hash
stringlengths 64
64
| content
stringlengths 0
1.51M
|
|---|---|
cff77fcba778e9e2f5e29dd63da171cc1db37c5fd824d175578485eb5d951491 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'd F Y'
TIME_FORMAT = 'g.i.A'
# DATETIME_FORMAT =
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'Y-m-d'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
# NUMBER_GROUPING =
|
164440b871c6be17824cee54f86e4367cbea085da943a019d9ca4a90533c7cc3 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'Y-m-d'
SHORT_DATETIME_FORMAT = 'Y-m-d H:i'
FIRST_DAY_OF_WEEK = 1
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', # '2006-10-25'
'%m/%d/%Y', # '10/25/2006'
'%m/%d/%y', # '10/25/06'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%m/%d/%Y %H:%M:%S', # '10/25/2006 14:30:59'
'%m/%d/%Y %H:%M:%S.%f', # '10/25/2006 14:30:59.000200'
'%m/%d/%Y %H:%M', # '10/25/2006 14:30'
'%m/%d/%Y', # '10/25/2006'
'%m/%d/%y %H:%M:%S', # '10/25/06 14:30:59'
'%m/%d/%y %H:%M:%S.%f', # '10/25/06 14:30:59.000200'
'%m/%d/%y %H:%M', # '10/25/06 14:30'
'%m/%d/%y', # '10/25/06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
f8ec538474005b0095adf54b0c092cb424147da007a5b26144f425a993bfc06a | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. F Y'
TIME_FORMAT = 'H:i'
# DATETIME_FORMAT =
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'j.n.Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
d4eeb7bcc0efe4c1bdba6e00bcc444280a2a94e6720b8e96304586f6af0f312f | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F, Y'
TIME_FORMAT = 'g:i A'
# DATETIME_FORMAT =
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M, Y'
# SHORT_DATETIME_FORMAT =
FIRST_DAY_OF_WEEK = 6 # Saturday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', # 25/10/2016
'%d/%m/%y', # 25/10/16
'%d-%m-%Y', # 25-10-2016
'%d-%m-%y', # 25-10-16
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # 14:30:59
'%H:%M', # 14:30
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S', # 25/10/2006 14:30:59
'%d/%m/%Y %H:%M', # 25/10/2006 14:30
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
# NUMBER_GROUPING =
|
acf58889b3e0f1bf30ecdc01cbbae885b14415cc533eb92b4a3bff30fd826016 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'j \d\e F \d\e Y'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = r'j \d\e F \d\e Y \a \l\e\s G:i'
YEAR_MONTH_FORMAT = r'F \d\e\l Y'
MONTH_DAY_FORMAT = r'j \d\e F'
SHORT_DATE_FORMAT = 'd/m/Y'
SHORT_DATETIME_FORMAT = 'd/m/Y G:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
# '31/12/2009', '31/12/09'
'%d/%m/%Y', '%d/%m/%y'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S',
'%d/%m/%Y %H:%M:%S.%f',
'%d/%m/%Y %H:%M',
'%d/%m/%y %H:%M:%S',
'%d/%m/%y %H:%M:%S.%f',
'%d/%m/%y %H:%M',
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
58aa7c177222212ae0c5722d4a9201d5cd1af31158f02b04cea5cc41161bb0f4 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y' # '25 Hydref 2006'
TIME_FORMAT = 'P' # '2:30 y.b.'
DATETIME_FORMAT = 'j F Y, P' # '25 Hydref 2006, 2:30 y.b.'
YEAR_MONTH_FORMAT = 'F Y' # 'Hydref 2006'
MONTH_DAY_FORMAT = 'j F' # '25 Hydref'
SHORT_DATE_FORMAT = 'd/m/Y' # '25/10/2006'
SHORT_DATETIME_FORMAT = 'd/m/Y P' # '25/10/2006 2:30 y.b.'
FIRST_DAY_OF_WEEK = 1 # 'Dydd Llun'
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', # '25/10/2006', '25/10/06'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%d/%m/%Y %H:%M:%S', # '25/10/2006 14:30:59'
'%d/%m/%Y %H:%M:%S.%f', # '25/10/2006 14:30:59.000200'
'%d/%m/%Y %H:%M', # '25/10/2006 14:30'
'%d/%m/%Y', # '25/10/2006'
'%d/%m/%y %H:%M:%S', # '25/10/06 14:30:59'
'%d/%m/%y %H:%M:%S.%f', # '25/10/06 14:30:59.000200'
'%d/%m/%y %H:%M', # '25/10/06 14:30'
'%d/%m/%y', # '25/10/06'
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
3bce2cc044e6bd5df2c4089f465e624c00f283e8af639adc5efb50cf6078aeb2 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'Y年n月j日'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'Y年n月j日G:i'
YEAR_MONTH_FORMAT = 'Y年n月'
MONTH_DAY_FORMAT = 'n月j日'
SHORT_DATE_FORMAT = 'Y/m/d'
SHORT_DATETIME_FORMAT = 'Y/m/d G:i'
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
# NUMBER_GROUPING =
|
bb04a9aa6185e8fcb2ddc9d8120c8d1f99bab6da17342fe9a1fa5b8eaa003bf2 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j N Y'
DATETIME_FORMAT = "j N Y, G.i"
TIME_FORMAT = 'G.i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd-m-Y'
SHORT_DATETIME_FORMAT = 'd-m-Y G.i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d-%m-%y', '%d/%m/%y', # '25-10-09', 25/10/09'
'%d-%m-%Y', '%d/%m/%Y', # '25-10-2009', 25/10/2009'
'%d %b %Y', # '25 Oct 2006',
'%d %B %Y', # '25 October 2006'
]
TIME_INPUT_FORMATS = [
'%H.%M.%S', # '14.30.59'
'%H.%M', # '14.30'
]
DATETIME_INPUT_FORMATS = [
'%d-%m-%Y %H.%M.%S', # '25-10-2009 14.30.59'
'%d-%m-%Y %H.%M.%S.%f', # '25-10-2009 14.30.59.000200'
'%d-%m-%Y %H.%M', # '25-10-2009 14.30'
'%d-%m-%Y', # '25-10-2009'
'%d-%m-%y %H.%M.%S', # '25-10-09' 14.30.59'
'%d-%m-%y %H.%M.%S.%f', # '25-10-09' 14.30.59.000200'
'%d-%m-%y %H.%M', # '25-10-09' 14.30'
'%d-%m-%y', # '25-10-09''
'%m/%d/%y %H.%M.%S', # '10/25/06 14.30.59'
'%m/%d/%y %H.%M.%S.%f', # '10/25/06 14.30.59.000200'
'%m/%d/%y %H.%M', # '10/25/06 14.30'
'%m/%d/%y', # '10/25/06'
'%m/%d/%Y %H.%M.%S', # '25/10/2009 14.30.59'
'%m/%d/%Y %H.%M.%S.%f', # '25/10/2009 14.30.59.000200'
'%m/%d/%Y %H.%M', # '25/10/2009 14.30'
'%m/%d/%Y', # '10/25/2009'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
4e755233a89478032ac9f0cd2e78c62b0062ce2540ee0c2fa241119b9e3d673c | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j M Y' # '25 Oct 2006'
TIME_FORMAT = 'P' # '2:30 p.m.'
DATETIME_FORMAT = 'j M Y, P' # '25 Oct 2006, 2:30 p.m.'
YEAR_MONTH_FORMAT = 'F Y' # 'October 2006'
MONTH_DAY_FORMAT = 'j F' # '25 October'
SHORT_DATE_FORMAT = 'd/m/Y' # '25/10/2006'
SHORT_DATETIME_FORMAT = 'd/m/Y P' # '25/10/2006 2:30 p.m.'
FIRST_DAY_OF_WEEK = 0 # Sunday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', # '25/10/2006', '25/10/06'
# '%b %d %Y', '%b %d, %Y', # 'Oct 25 2006', 'Oct 25, 2006'
# '%d %b %Y', '%d %b, %Y', # '25 Oct 2006', '25 Oct, 2006'
# '%B %d %Y', '%B %d, %Y', # 'October 25 2006', 'October 25, 2006'
# '%d %B %Y', '%d %B, %Y', # '25 October 2006', '25 October, 2006'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%d/%m/%Y %H:%M:%S', # '25/10/2006 14:30:59'
'%d/%m/%Y %H:%M:%S.%f', # '25/10/2006 14:30:59.000200'
'%d/%m/%Y %H:%M', # '25/10/2006 14:30'
'%d/%m/%Y', # '25/10/2006'
'%d/%m/%y %H:%M:%S', # '25/10/06 14:30:59'
'%d/%m/%y %H:%M:%S.%f', # '25/10/06 14:30:59.000200'
'%d/%m/%y %H:%M', # '25/10/06 14:30'
'%d/%m/%y', # '25/10/06'
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
d1617f2126d848dd0db4fb8e935b05b1821308f6f7206da311a0315525cb6aa5 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'd/m/Y'
TIME_FORMAT = 'P'
DATETIME_FORMAT = 'd/m/Y P'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd/m/Y'
SHORT_DATETIME_FORMAT = 'd/m/Y P'
FIRST_DAY_OF_WEEK = 0 # Sunday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', '%Y-%m-%d', # '25/10/2006', '25/10/06', '2006-10-25',
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S', # '25/10/2006 14:30:59'
'%d/%m/%Y %H:%M:%S.%f', # '25/10/2006 14:30:59.000200'
'%d/%m/%Y %H:%M', # '25/10/2006 14:30'
'%d/%m/%Y', # '25/10/2006'
'%d/%m/%y %H:%M:%S', # '25/10/06 14:30:59'
'%d/%m/%y %H:%M:%S.%f', # '25/10/06 14:30:59.000200'
'%d/%m/%y %H:%M', # '25/10/06 14:30'
'%d/%m/%y', # '25/10/06'
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
64b98a58580ac2b1de0de4cee9f3f244b8e0c645374022b77f42f19d884bbea8 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'Y \m. E j \d.'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'Y \m. E j \d., H:i'
YEAR_MONTH_FORMAT = r'Y \m. F'
MONTH_DAY_FORMAT = r'E j \d.'
SHORT_DATE_FORMAT = 'Y-m-d'
SHORT_DATETIME_FORMAT = 'Y-m-d H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%Y-%m-%d', '%d.%m.%Y', '%d.%m.%y', # '2006-10-25', '25.10.2006', '25.10.06'
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '14:30:59'
'%H:%M:%S.%f', # '14:30:59.000200'
'%H:%M', # '14:30'
'%H.%M.%S', # '14.30.59'
'%H.%M.%S.%f', # '14.30.59.000200'
'%H.%M', # '14.30'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y %H.%M.%S', # '25.10.06 14.30.59'
'%d.%m.%y %H.%M.%S.%f', # '25.10.06 14.30.59.000200'
'%d.%m.%y %H.%M', # '25.10.06 14.30'
'%d.%m.%y', # '25.10.06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
998296ba691f1849460cbf761b49cefe5a01a1238e14ab3492db08dfefa794b4 | # This file is distributed under the same license as the Django package.
#
DATE_FORMAT = r'j \d\e F \d\e Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'j \d\e F \d\e Y \a \l\a\s H:i'
YEAR_MONTH_FORMAT = r'F \d\e Y'
MONTH_DAY_FORMAT = r'j \d\e F'
SHORT_DATE_FORMAT = 'd/m/Y'
SHORT_DATETIME_FORMAT = 'd/m/Y H:i'
FIRST_DAY_OF_WEEK = 0 # Sunday
DATE_INPUT_FORMATS = [
# '31/12/2009', '31/12/09'
'%d/%m/%Y', '%d/%m/%y'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S',
'%d/%m/%Y %H:%M:%S.%f',
'%d/%m/%Y %H:%M',
'%d/%m/%y %H:%M:%S',
'%d/%m/%y %H:%M:%S.%f',
'%d/%m/%y %H:%M',
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
cbb5d63e1b8ebfb4240c1bf1e2a9307a19aa469ab02f39fbe455a7fb6e66bdc7 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j. F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'd.m.Y'
SHORT_DATETIME_FORMAT = 'd.m.Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', '%d.%m.%Y', '%d.%m.%y', # '2006-10-25', '25.10.2006', '25.10.06'
# '%d. %b %Y', '%d %b %Y', # '25. okt 2006', '25 okt 2006'
# '%d. %b. %Y', '%d %b. %Y', # '25. okt. 2006', '25 okt. 2006'
# '%d. %B %Y', '%d %B %Y', # '25. oktober 2006', '25 oktober 2006'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y', # '25.10.06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
fb01e9f871546ad9931201a243b7a408c14c07c8e90100f8502e269a18d14cbf | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
# DATE_FORMAT =
# TIME_FORMAT =
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
# MONTH_DAY_FORMAT =
# SHORT_DATE_FORMAT =
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
# DECIMAL_SEPARATOR =
# THOUSAND_SEPARATOR =
# NUMBER_GROUPING =
|
be11c5378964cce4004515e182de6cf0cec84d32d930c2d5c1b8dbcbe63f5049 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'j N Y'
TIME_FORMAT = r'H:i'
DATETIME_FORMAT = r'j N Y H:i'
YEAR_MONTH_FORMAT = r'F Y'
MONTH_DAY_FORMAT = r'j \d\e F'
SHORT_DATE_FORMAT = r'd/m/Y'
SHORT_DATETIME_FORMAT = r'd/m/Y H:i'
FIRST_DAY_OF_WEEK = 0 # 0: Sunday, 1: Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', # '31/12/2009'
'%d/%m/%y', # '31/12/09'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S',
'%d/%m/%Y %H:%M:%S.%f',
'%d/%m/%Y %H:%M',
'%d/%m/%y %H:%M:%S',
'%d/%m/%y %H:%M:%S.%f',
'%d/%m/%y %H:%M',
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
c64b3fe138d84d21b2cfd70861a13c38cdf06ee78fde8a0cd904eca8d3ce305f | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'j \d\e F \d\e Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'j \d\e F \d\e Y \a \l\a\s H:i'
YEAR_MONTH_FORMAT = r'F \d\e Y'
MONTH_DAY_FORMAT = r'j \d\e F'
SHORT_DATE_FORMAT = 'd/m/Y'
SHORT_DATETIME_FORMAT = 'd/m/Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
# '31/12/2009', '31/12/09'
'%d/%m/%Y', '%d/%m/%y'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S',
'%d/%m/%Y %H:%M:%S.%f',
'%d/%m/%Y %H:%M',
'%d/%m/%y %H:%M:%S',
'%d/%m/%y %H:%M:%S.%f',
'%d/%m/%y %H:%M',
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
acd781329bfaa7e7894b3759bd3c86b830c3226df163b14ab04a5ec85674e69d | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'j\-\a \d\e F Y' # '26-a de julio 1887'
TIME_FORMAT = 'H:i' # '18:59'
DATETIME_FORMAT = r'j\-\a \d\e F Y\, \j\e H:i' # '26-a de julio 1887, je 18:59'
YEAR_MONTH_FORMAT = r'F \d\e Y' # 'julio de 1887'
MONTH_DAY_FORMAT = r'j\-\a \d\e F' # '26-a de julio'
SHORT_DATE_FORMAT = 'Y-m-d' # '1887-07-26'
SHORT_DATETIME_FORMAT = 'Y-m-d H:i' # '1887-07-26 18:59'
FIRST_DAY_OF_WEEK = 1 # Monday (lundo)
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%Y-%m-%d', # '1887-07-26'
'%y-%m-%d', # '87-07-26'
'%Y %m %d', # '1887 07 26'
'%d-a de %b %Y', # '26-a de jul 1887'
'%d %b %Y', # '26 jul 1887'
'%d-a de %B %Y', # '26-a de julio 1887'
'%d %B %Y', # '26 julio 1887'
'%d %m %Y', # '26 07 1887'
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '18:59:00'
'%H:%M', # '18:59'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '1887-07-26 18:59:00'
'%Y-%m-%d %H:%M', # '1887-07-26 18:59'
'%Y-%m-%d', # '1887-07-26'
'%Y.%m.%d %H:%M:%S', # '1887.07.26 18:59:00'
'%Y.%m.%d %H:%M', # '1887.07.26 18:59'
'%Y.%m.%d', # '1887.07.26'
'%d/%m/%Y %H:%M:%S', # '26/07/1887 18:59:00'
'%d/%m/%Y %H:%M', # '26/07/1887 18:59'
'%d/%m/%Y', # '26/07/1887'
'%y-%m-%d %H:%M:%S', # '87-07-26 18:59:00'
'%y-%m-%d %H:%M', # '87-07-26 18:59'
'%y-%m-%d', # '87-07-26'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
b656da110f7de0fe818fe5258976a0316e18bb50ff9de1aca4339a40b2f91e55 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. E Y'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'j. E Y G:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'd.m.Y'
SHORT_DATETIME_FORMAT = 'd.m.Y G:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', '%d.%m.%y', # '05.01.2006', '05.01.06'
'%d. %m. %Y', '%d. %m. %y', # '5. 1. 2006', '5. 1. 06'
# '%d. %B %Y', '%d. %b. %Y', # '25. October 2006', '25. Oct. 2006'
]
# Kept ISO formats as one is in first position
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '04:30:59'
'%H.%M', # '04.30'
'%H:%M', # '04:30'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '05.01.2006 04:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '05.01.2006 04:30:59.000200'
'%d.%m.%Y %H.%M', # '05.01.2006 04.30'
'%d.%m.%Y %H:%M', # '05.01.2006 04:30'
'%d.%m.%Y', # '05.01.2006'
'%d. %m. %Y %H:%M:%S', # '05. 01. 2006 04:30:59'
'%d. %m. %Y %H:%M:%S.%f', # '05. 01. 2006 04:30:59.000200'
'%d. %m. %Y %H.%M', # '05. 01. 2006 04.30'
'%d. %m. %Y %H:%M', # '05. 01. 2006 04:30'
'%d. %m. %Y', # '05. 01. 2006'
'%Y-%m-%d %H.%M', # '2006-01-05 04.30'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
558430e49a452b818a381f4b85571448ba6b53bffae903f5241bb65d6b2ce0bd | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. E Y.'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j. E Y. H:i'
YEAR_MONTH_FORMAT = 'F Y.'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'j.m.Y.'
SHORT_DATETIME_FORMAT = 'j.m.Y. H:i'
FIRST_DAY_OF_WEEK = 1
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', # '2006-10-25'
'%d.%m.%Y.', '%d.%m.%y.', # '25.10.2006.', '25.10.06.'
'%d. %m. %Y.', '%d. %m. %y.', # '25. 10. 2006.', '25. 10. 06.'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%d.%m.%Y. %H:%M:%S', # '25.10.2006. 14:30:59'
'%d.%m.%Y. %H:%M:%S.%f', # '25.10.2006. 14:30:59.000200'
'%d.%m.%Y. %H:%M', # '25.10.2006. 14:30'
'%d.%m.%Y.', # '25.10.2006.'
'%d.%m.%y. %H:%M:%S', # '25.10.06. 14:30:59'
'%d.%m.%y. %H:%M:%S.%f', # '25.10.06. 14:30:59.000200'
'%d.%m.%y. %H:%M', # '25.10.06. 14:30'
'%d.%m.%y.', # '25.10.06.'
'%d. %m. %Y. %H:%M:%S', # '25. 10. 2006. 14:30:59'
'%d. %m. %Y. %H:%M:%S.%f', # '25. 10. 2006. 14:30:59.000200'
'%d. %m. %Y. %H:%M', # '25. 10. 2006. 14:30'
'%d. %m. %Y.', # '25. 10. 2006.'
'%d. %m. %y. %H:%M:%S', # '25. 10. 06. 14:30:59'
'%d. %m. %y. %H:%M:%S.%f', # '25. 10. 06. 14:30:59.000200'
'%d. %m. %y. %H:%M', # '25. 10. 06. 14:30'
'%d. %m. %y.', # '25. 10. 06.'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
f0a09256d9373785acae5c7a8460e3f0f6d557ab18b218257f22eda426c5af14 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'\N\gà\y d \t\há\n\g n \nă\m Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'H:i \N\gà\y d \t\há\n\g n \nă\m Y'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd-m-Y'
SHORT_DATETIME_FORMAT = 'H:i d-m-Y'
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
# NUMBER_GROUPING =
|
40c7c7a0459ca51ffcc8b684ebac3952398f8ed813014ed8962f091e04b11912 | # This file is distributed under the same license as the Django package.
#
DATE_FORMAT = r'j \d\e F \d\e Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'j \d\e F \d\e Y \a \l\a\s H:i'
YEAR_MONTH_FORMAT = r'F \d\e Y'
MONTH_DAY_FORMAT = r'j \d\e F'
SHORT_DATE_FORMAT = 'd/m/Y'
SHORT_DATETIME_FORMAT = 'd/m/Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday: ISO 8601
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', # '25/10/2006', '25/10/06'
'%Y%m%d', # '20061025'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S',
'%d/%m/%Y %H:%M:%S.%f',
'%d/%m/%Y %H:%M',
'%d/%m/%y %H:%M:%S',
'%d/%m/%y %H:%M:%S.%f',
'%d/%m/%y %H:%M',
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
8ae05a8f2e9b805fb65748f9c598eff7cdf64e82e750cc91bf35432b8bea3bbe | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. N Y.'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'j. N. Y. G:i T'
YEAR_MONTH_FORMAT = 'F Y.'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'Y M j'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
# NUMBER_GROUPING =
|
8322cea64eeed5eecb341a100c72ece24230d38cbbbe61a81bdbf56aaecd8e61 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F, Y'
TIME_FORMAT = 'g:i A'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M, Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
# DECIMAL_SEPARATOR =
# THOUSAND_SEPARATOR =
# NUMBER_GROUPING =
|
0c9545a9ba96eddaba18fce1fcc49142f40089c06d554c111d7f1148b82aa458 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'd F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j. F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'j.m.Y'
SHORT_DATETIME_FORMAT = 'j.m.Y H:i'
FIRST_DAY_OF_WEEK = 1
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', '%d.%m.%y', # '25.10.2006', '25.10.06'
'%d. %m. %Y', '%d. %m. %y', # '25. 10. 2006', '25. 10. 06'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y', # '25.10.06'
'%d. %m. %Y %H:%M:%S', # '25. 10. 2006 14:30:59'
'%d. %m. %Y %H:%M:%S.%f', # '25. 10. 2006 14:30:59.000200'
'%d. %m. %Y %H:%M', # '25. 10. 2006 14:30'
'%d. %m. %Y', # '25. 10. 2006'
'%d. %m. %y %H:%M:%S', # '25. 10. 06 14:30:59'
'%d. %m. %y %H:%M:%S.%f', # '25. 10. 06 14:30:59.000200'
'%d. %m. %y %H:%M', # '25. 10. 06 14:30'
'%d. %m. %y', # '25. 10. 06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
a352ba7dbf00c09e621ea4b15a2ac7fea2e1169e78bd1990d1c5037844091598 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'H:i'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
# NUMBER_GROUPING =
|
97f9744df438a57182dc79a18732b261a812ea2f4225368e71466f4f8cd4e0f6 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j E Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j E Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd-m-Y'
SHORT_DATETIME_FORMAT = 'd-m-Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', '%d.%m.%y', # '25.10.2006', '25.10.06'
'%y-%m-%d', # '06-10-25'
# '%d. %B %Y', '%d. %b. %Y', # '25. October 2006', '25. Oct. 2006'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = ' '
NUMBER_GROUPING = 3
|
d95d29612cd7aafd5c6e46000109e4ff727c7729e85f42e66ba27a3376cb9c18 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. F Y'
TIME_FORMAT = 'G:i'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'd.m.Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = ' ' # Non-breaking space
# NUMBER_GROUPING =
|
2bd25b909b97766afccf528000206f0f16bc98824843cf837c72e5be391f9b7f | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'd F Y'
TIME_FORMAT = 'H:i'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd.m.Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = ' ' # Non-breaking space
# NUMBER_GROUPING =
|
6b5df734fc3baf2d96606b3b6f75fb3c6042f861d4b4dd92e737232e9f424c9c | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'g:i A'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
# DECIMAL_SEPARATOR =
# THOUSAND_SEPARATOR =
# NUMBER_GROUPING =
|
92f4ec29268aee80d62ba6be49e3b75777bfffae128ed0c1316a2ad28b950c9e | # This file is distributed under the same license as the Django package.
#
DATE_FORMAT = r'j \d\e F \d\e Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'j \d\e F \d\e Y \a \l\a\s H:i'
YEAR_MONTH_FORMAT = r'F \d\e Y'
MONTH_DAY_FORMAT = r'j \d\e F'
SHORT_DATE_FORMAT = 'd/m/Y'
SHORT_DATETIME_FORMAT = 'd/m/Y H:i'
FIRST_DAY_OF_WEEK = 1
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', # '25/10/2006', '25/10/06'
'%Y%m%d', # '20061025'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S',
'%d/%m/%Y %H:%M:%S.%f',
'%d/%m/%Y %H:%M',
'%d/%m/%y %H:%M:%S',
'%d/%m/%y %H:%M:%S.%f',
'%d/%m/%y %H:%M',
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
e7ee47b78d26824d1ca2f620368a99362d325f595d8c2e55206b192dbe8217d1 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'Y년 n월 j일'
TIME_FORMAT = 'A g:i'
DATETIME_FORMAT = 'Y년 n월 j일 g:i A'
YEAR_MONTH_FORMAT = 'Y년 n월'
MONTH_DAY_FORMAT = 'n월 j일'
SHORT_DATE_FORMAT = 'Y-n-j.'
SHORT_DATETIME_FORMAT = 'Y-n-j H:i'
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', '%m/%d/%Y', '%m/%d/%y', # '2006-10-25', '10/25/2006', '10/25/06'
# '%b %d %Y', '%b %d, %Y', # 'Oct 25 2006', 'Oct 25, 2006'
# '%d %b %Y', '%d %b, %Y', # '25 Oct 2006', '25 Oct, 2006'
# '%B %d %Y', '%B %d, %Y', # 'October 25 2006', 'October 25, 2006'
# '%d %B %Y', '%d %B, %Y', # '25 October 2006', '25 October, 2006'
'%Y년 %m월 %d일', # '2006년 10월 25일', with localized suffix.
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '14:30:59'
'%H:%M:%S.%f', # '14:30:59.000200'
'%H:%M', # '14:30'
'%H시 %M분 %S초', # '14시 30분 59초'
'%H시 %M분', # '14시 30분'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%Y-%m-%d', # '2006-10-25'
'%m/%d/%Y %H:%M:%S', # '10/25/2006 14:30:59'
'%m/%d/%Y %H:%M:%S.%f', # '10/25/2006 14:30:59.000200'
'%m/%d/%Y %H:%M', # '10/25/2006 14:30'
'%m/%d/%Y', # '10/25/2006'
'%m/%d/%y %H:%M:%S', # '10/25/06 14:30:59'
'%m/%d/%y %H:%M:%S.%f', # '10/25/06 14:30:59.000200'
'%m/%d/%y %H:%M', # '10/25/06 14:30'
'%m/%d/%y', # '10/25/06'
'%Y년 %m월 %d일 %H시 %M분 %S초', # '2006년 10월 25일 14시 30분 59초'
'%Y년 %m월 %d일 %H시 %M분', # '2006년 10월 25일 14시 30분'
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
4b704ad856ce75975452c3e9f081cc6f81a90e6fdcb48204d73e195f72fb1752 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j N Y'
SHORT_DATETIME_FORMAT = 'j N Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', '%d/%m/%y', # '25/10/2006', '25/10/06'
'%d.%m.%Y', '%d.%m.%y', # Swiss [fr_CH), '25.10.2006', '25.10.06'
# '%d %B %Y', '%d %b %Y', # '25 octobre 2006', '25 oct. 2006'
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S', # '25/10/2006 14:30:59'
'%d/%m/%Y %H:%M:%S.%f', # '25/10/2006 14:30:59.000200'
'%d/%m/%Y %H:%M', # '25/10/2006 14:30'
'%d/%m/%Y', # '25/10/2006'
'%d.%m.%Y %H:%M:%S', # Swiss [fr_CH), '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # Swiss (fr_CH), '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # Swiss (fr_CH), '25.10.2006 14:30'
'%d.%m.%Y', # Swiss (fr_CH), '25.10.2006'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
4c23f4ac2692eef1658527ce2176da07143a2de25f3ac492a4dc2e7ddec56548 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'j F Y, G:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'j M Y'
SHORT_DATETIME_FORMAT = 'j M Y, G:i'
FIRST_DAY_OF_WEEK = 0 # Sunday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d/%m/%Y', # 25/10/2006
'%d %b %Y', # 25 ต.ค. 2006
'%d %B %Y', # 25 ตุลาคม 2006
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # 14:30:59
'%H:%M:%S.%f', # 14:30:59.000200
'%H:%M', # 14:30
]
DATETIME_INPUT_FORMATS = [
'%d/%m/%Y %H:%M:%S', # 25/10/2006 14:30:59
'%d/%m/%Y %H:%M:%S.%f', # 25/10/2006 14:30:59.000200
'%d/%m/%Y %H:%M', # 25/10/2006 14:30
]
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
NUMBER_GROUPING = 3
|
438dbe5d9e5a5ad7e82a12ae7f4ef5e3c22bebe52b8da58d35e03c7ab06d9421 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = r'Y. \g\a\d\a j. F'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = r'Y. \g\a\d\a j. F, H:i'
YEAR_MONTH_FORMAT = r'Y. \g. F'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = r'j.m.Y'
SHORT_DATETIME_FORMAT = 'j.m.Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# Kept ISO formats as they are in first position
DATE_INPUT_FORMATS = [
'%Y-%m-%d', '%d.%m.%Y', '%d.%m.%y', # '2006-10-25', '25.10.2006', '25.10.06'
]
TIME_INPUT_FORMATS = [
'%H:%M:%S', # '14:30:59'
'%H:%M:%S.%f', # '14:30:59.000200'
'%H:%M', # '14:30'
'%H.%M.%S', # '14.30.59'
'%H.%M.%S.%f', # '14.30.59.000200'
'%H.%M', # '14.30'
]
DATETIME_INPUT_FORMATS = [
'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
'%Y-%m-%d %H:%M:%S.%f', # '2006-10-25 14:30:59.000200'
'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y %H.%M.%S', # '25.10.06 14.30.59'
'%d.%m.%y %H.%M.%S.%f', # '25.10.06 14.30.59.000200'
'%d.%m.%y %H.%M', # '25.10.06 14.30'
'%d.%m.%y', # '25.10.06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = ' ' # Non-breaking space
NUMBER_GROUPING = 3
|
61068bf18dc7d0038fbc9cf1c220d7c2daab6d8d04c87346b5f32ee011a16b46 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j. F Y'
TIME_FORMAT = 'H:i'
DATETIME_FORMAT = 'j. F Y H:i'
YEAR_MONTH_FORMAT = 'F Y'
MONTH_DAY_FORMAT = 'j. F'
SHORT_DATE_FORMAT = 'd.m.Y'
SHORT_DATETIME_FORMAT = 'd.m.Y H:i'
FIRST_DAY_OF_WEEK = 1
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', # '25.10.2006'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '.'
NUMBER_GROUPING = 3
|
cb43b91780b7d708093173dd56b42f36a60a572afcf99d617f9a3437d3f78bb3 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j F Y'
TIME_FORMAT = 'g:i A'
# DATETIME_FORMAT =
# YEAR_MONTH_FORMAT =
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd-m-Y'
# SHORT_DATETIME_FORMAT =
# FIRST_DAY_OF_WEEK =
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
# DATE_INPUT_FORMATS =
# TIME_INPUT_FORMATS =
# DATETIME_INPUT_FORMATS =
DECIMAL_SEPARATOR = '.'
THOUSAND_SEPARATOR = ','
# NUMBER_GROUPING =
|
c47d76ebdf6237fd5207f49e0482dc3193534b9d4fa95cd998d7e84ceffd2b90 | # This file is distributed under the same license as the Django package.
#
# The *_FORMAT strings use the Django date format syntax,
# see http://docs.djangoproject.com/en/dev/ref/templates/builtins/#date
DATE_FORMAT = 'j E Y г.'
TIME_FORMAT = 'G:i'
DATETIME_FORMAT = 'j E Y г. G:i'
YEAR_MONTH_FORMAT = 'F Y г.'
MONTH_DAY_FORMAT = 'j F'
SHORT_DATE_FORMAT = 'd.m.Y'
SHORT_DATETIME_FORMAT = 'd.m.Y H:i'
FIRST_DAY_OF_WEEK = 1 # Monday
# The *_INPUT_FORMATS strings use the Python strftime format syntax,
# see http://docs.python.org/library/datetime.html#strftime-strptime-behavior
DATE_INPUT_FORMATS = [
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y', # '25.10.06'
]
DATETIME_INPUT_FORMATS = [
'%d.%m.%Y %H:%M:%S', # '25.10.2006 14:30:59'
'%d.%m.%Y %H:%M:%S.%f', # '25.10.2006 14:30:59.000200'
'%d.%m.%Y %H:%M', # '25.10.2006 14:30'
'%d.%m.%Y', # '25.10.2006'
'%d.%m.%y %H:%M:%S', # '25.10.06 14:30:59'
'%d.%m.%y %H:%M:%S.%f', # '25.10.06 14:30:59.000200'
'%d.%m.%y %H:%M', # '25.10.06 14:30'
'%d.%m.%y', # '25.10.06'
]
DECIMAL_SEPARATOR = ','
THOUSAND_SEPARATOR = '\xa0' # non-breaking space
NUMBER_GROUPING = 3
|
c36e892478a571c0130c9ade9f4dc4c0e52836f3d0b46438a8734f6ae52a1ca9 | """Translation helper functions."""
import functools
import gettext as gettext_module
import os
import re
import sys
import warnings
from collections import OrderedDict
from threading import local
from django.apps import apps
from django.conf import settings
from django.conf.locale import LANG_INFO
from django.core.exceptions import AppRegistryNotReady
from django.core.signals import setting_changed
from django.dispatch import receiver
from django.utils.safestring import SafeData, mark_safe
from . import LANGUAGE_SESSION_KEY, to_language, to_locale
# Translations are cached in a dictionary for every language.
# The active translations are stored by threadid to make them thread local.
_translations = {}
_active = local()
# The default translation is based on the settings file.
_default = None
# magic gettext number to separate context from message
CONTEXT_SEPARATOR = "\x04"
# Format of Accept-Language header values. From RFC 2616, section 14.4 and 3.9
# and RFC 3066, section 2.1
accept_language_re = re.compile(r'''
([A-Za-z]{1,8}(?:-[A-Za-z0-9]{1,8})*|\*) # "en", "en-au", "x-y-z", "es-419", "*"
(?:\s*;\s*q=(0(?:\.\d{,3})?|1(?:\.0{,3})?))? # Optional "q=1.00", "q=0.8"
(?:\s*,\s*|$) # Multiple accepts per header.
''', re.VERBOSE)
language_code_re = re.compile(
r'^[a-z]{1,8}(?:-[a-z0-9]{1,8})*(?:@[a-z0-9]{1,20})?$',
re.IGNORECASE
)
language_code_prefix_re = re.compile(r'^/(\w+([@-]\w+)?)(/|$)')
@receiver(setting_changed)
def reset_cache(**kwargs):
"""
Reset global state when LANGUAGES setting has been changed, as some
languages should no longer be accepted.
"""
if kwargs['setting'] in ('LANGUAGES', 'LANGUAGE_CODE'):
check_for_language.cache_clear()
get_languages.cache_clear()
get_supported_language_variant.cache_clear()
class DjangoTranslation(gettext_module.GNUTranslations):
"""
Set up the GNUTranslations context with regard to output charset.
This translation object will be constructed out of multiple GNUTranslations
objects by merging their catalogs. It will construct an object for the
requested language and add a fallback to the default language, if it's
different from the requested language.
"""
domain = 'django'
def __init__(self, language, domain=None, localedirs=None):
"""Create a GNUTranslations() using many locale directories"""
gettext_module.GNUTranslations.__init__(self)
if domain is not None:
self.domain = domain
self.__language = language
self.__to_language = to_language(language)
self.__locale = to_locale(language)
self._catalog = None
# If a language doesn't have a catalog, use the Germanic default for
# pluralization: anything except one is pluralized.
self.plural = lambda n: int(n != 1)
if self.domain == 'django':
if localedirs is not None:
# A module-level cache is used for caching 'django' translations
warnings.warn("localedirs is ignored when domain is 'django'.", RuntimeWarning)
localedirs = None
self._init_translation_catalog()
if localedirs:
for localedir in localedirs:
translation = self._new_gnu_trans(localedir)
self.merge(translation)
else:
self._add_installed_apps_translations()
self._add_local_translations()
if self.__language == settings.LANGUAGE_CODE and self.domain == 'django' and self._catalog is None:
# default lang should have at least one translation file available.
raise IOError("No translation files found for default language %s." % settings.LANGUAGE_CODE)
self._add_fallback(localedirs)
if self._catalog is None:
# No catalogs found for this language, set an empty catalog.
self._catalog = {}
def __repr__(self):
return "<DjangoTranslation lang:%s>" % self.__language
def _new_gnu_trans(self, localedir, use_null_fallback=True):
"""
Return a mergeable gettext.GNUTranslations instance.
A convenience wrapper. By default gettext uses 'fallback=False'.
Using param `use_null_fallback` to avoid confusion with any other
references to 'fallback'.
"""
return gettext_module.translation(
domain=self.domain,
localedir=localedir,
languages=[self.__locale],
codeset='utf-8',
fallback=use_null_fallback,
)
def _init_translation_catalog(self):
"""Create a base catalog using global django translations."""
settingsfile = sys.modules[settings.__module__].__file__
localedir = os.path.join(os.path.dirname(settingsfile), 'locale')
translation = self._new_gnu_trans(localedir)
self.merge(translation)
def _add_installed_apps_translations(self):
"""Merge translations from each installed app."""
try:
app_configs = reversed(list(apps.get_app_configs()))
except AppRegistryNotReady:
raise AppRegistryNotReady(
"The translation infrastructure cannot be initialized before the "
"apps registry is ready. Check that you don't make non-lazy "
"gettext calls at import time.")
for app_config in app_configs:
localedir = os.path.join(app_config.path, 'locale')
if os.path.exists(localedir):
translation = self._new_gnu_trans(localedir)
self.merge(translation)
def _add_local_translations(self):
"""Merge translations defined in LOCALE_PATHS."""
for localedir in reversed(settings.LOCALE_PATHS):
translation = self._new_gnu_trans(localedir)
self.merge(translation)
def _add_fallback(self, localedirs=None):
"""Set the GNUTranslations() fallback with the default language."""
# Don't set a fallback for the default language or any English variant
# (as it's empty, so it'll ALWAYS fall back to the default language)
if self.__language == settings.LANGUAGE_CODE or self.__language.startswith('en'):
return
if self.domain == 'django':
# Get from cache
default_translation = translation(settings.LANGUAGE_CODE)
else:
default_translation = DjangoTranslation(
settings.LANGUAGE_CODE, domain=self.domain, localedirs=localedirs
)
self.add_fallback(default_translation)
def merge(self, other):
"""Merge another translation into this catalog."""
if not getattr(other, '_catalog', None):
return # NullTranslations() has no _catalog
if self._catalog is None:
# Take plural and _info from first catalog found (generally Django's).
self.plural = other.plural
self._info = other._info.copy()
self._catalog = other._catalog.copy()
else:
self._catalog.update(other._catalog)
if other._fallback:
self.add_fallback(other._fallback)
def language(self):
"""Return the translation language."""
return self.__language
def to_language(self):
"""Return the translation language name."""
return self.__to_language
def translation(language):
"""
Return a translation object in the default 'django' domain.
"""
global _translations
if language not in _translations:
_translations[language] = DjangoTranslation(language)
return _translations[language]
def activate(language):
"""
Fetch the translation object for a given language and install it as the
current translation object for the current thread.
"""
if not language:
return
_active.value = translation(language)
def deactivate():
"""
Uninstall the active translation object so that further _() calls resolve
to the default translation object.
"""
if hasattr(_active, "value"):
del _active.value
def deactivate_all():
"""
Make the active translation object a NullTranslations() instance. This is
useful when we want delayed translations to appear as the original string
for some reason.
"""
_active.value = gettext_module.NullTranslations()
_active.value.to_language = lambda *args: None
def get_language():
"""Return the currently selected language."""
t = getattr(_active, "value", None)
if t is not None:
try:
return t.to_language()
except AttributeError:
pass
# If we don't have a real translation object, assume it's the default language.
return settings.LANGUAGE_CODE
def get_language_bidi():
"""
Return selected language's BiDi layout.
* False = left-to-right layout
* True = right-to-left layout
"""
lang = get_language()
if lang is None:
return False
else:
base_lang = get_language().split('-')[0]
return base_lang in settings.LANGUAGES_BIDI
def catalog():
"""
Return the current active catalog for further processing.
This can be used if you need to modify the catalog or want to access the
whole message catalog instead of just translating one string.
"""
global _default
t = getattr(_active, "value", None)
if t is not None:
return t
if _default is None:
_default = translation(settings.LANGUAGE_CODE)
return _default
def gettext(message):
"""
Translate the 'message' string. It uses the current thread to find the
translation object to use. If no current translation is activated, the
message will be run through the default translation object.
"""
global _default
eol_message = message.replace('\r\n', '\n').replace('\r', '\n')
if eol_message:
_default = _default or translation(settings.LANGUAGE_CODE)
translation_object = getattr(_active, "value", _default)
result = translation_object.gettext(eol_message)
else:
# Return an empty value of the corresponding type if an empty message
# is given, instead of metadata, which is the default gettext behavior.
result = type(message)('')
if isinstance(message, SafeData):
return mark_safe(result)
return result
def pgettext(context, message):
msg_with_ctxt = "%s%s%s" % (context, CONTEXT_SEPARATOR, message)
result = gettext(msg_with_ctxt)
if CONTEXT_SEPARATOR in result:
# Translation not found
result = message
elif isinstance(message, SafeData):
result = mark_safe(result)
return result
def gettext_noop(message):
"""
Mark strings for translation but don't translate them now. This can be
used to store strings in global variables that should stay in the base
language (because they might be used externally) and will be translated
later.
"""
return message
def do_ntranslate(singular, plural, number, translation_function):
global _default
t = getattr(_active, "value", None)
if t is not None:
return getattr(t, translation_function)(singular, plural, number)
if _default is None:
_default = translation(settings.LANGUAGE_CODE)
return getattr(_default, translation_function)(singular, plural, number)
def ngettext(singular, plural, number):
"""
Return a string of the translation of either the singular or plural,
based on the number.
"""
return do_ntranslate(singular, plural, number, 'ngettext')
def npgettext(context, singular, plural, number):
msgs_with_ctxt = ("%s%s%s" % (context, CONTEXT_SEPARATOR, singular),
"%s%s%s" % (context, CONTEXT_SEPARATOR, plural),
number)
result = ngettext(*msgs_with_ctxt)
if CONTEXT_SEPARATOR in result:
# Translation not found
result = ngettext(singular, plural, number)
return result
def all_locale_paths():
"""
Return a list of paths to user-provides languages files.
"""
globalpath = os.path.join(
os.path.dirname(sys.modules[settings.__module__].__file__), 'locale')
app_paths = []
for app_config in apps.get_app_configs():
locale_path = os.path.join(app_config.path, 'locale')
if os.path.exists(locale_path):
app_paths.append(locale_path)
return [globalpath] + list(settings.LOCALE_PATHS) + app_paths
@functools.lru_cache(maxsize=1000)
def check_for_language(lang_code):
"""
Check whether there is a global language file for the given language
code. This is used to decide whether a user-provided language is
available.
lru_cache should have a maxsize to prevent from memory exhaustion attacks,
as the provided language codes are taken from the HTTP request. See also
<https://www.djangoproject.com/weblog/2007/oct/26/security-fix/>.
"""
# First, a quick check to make sure lang_code is well-formed (#21458)
if lang_code is None or not language_code_re.search(lang_code):
return False
return any(
gettext_module.find('django', path, [to_locale(lang_code)]) is not None
for path in all_locale_paths()
)
@functools.lru_cache()
def get_languages():
"""
Cache of settings.LANGUAGES in an OrderedDict for easy lookups by key.
"""
return OrderedDict(settings.LANGUAGES)
@functools.lru_cache(maxsize=1000)
def get_supported_language_variant(lang_code, strict=False):
"""
Return the language code that's listed in supported languages, possibly
selecting a more generic variant. Raise LookupError if nothing is found.
If `strict` is False (the default), look for a country-specific variant
when neither the language code nor its generic variant is found.
lru_cache should have a maxsize to prevent from memory exhaustion attacks,
as the provided language codes are taken from the HTTP request. See also
<https://www.djangoproject.com/weblog/2007/oct/26/security-fix/>.
"""
if lang_code:
# If 'fr-ca' is not supported, try special fallback or language-only 'fr'.
possible_lang_codes = [lang_code]
try:
possible_lang_codes.extend(LANG_INFO[lang_code]['fallback'])
except KeyError:
pass
generic_lang_code = lang_code.split('-')[0]
possible_lang_codes.append(generic_lang_code)
supported_lang_codes = get_languages()
for code in possible_lang_codes:
if code in supported_lang_codes and check_for_language(code):
return code
if not strict:
# if fr-fr is not supported, try fr-ca.
for supported_code in supported_lang_codes:
if supported_code.startswith(generic_lang_code + '-'):
return supported_code
raise LookupError(lang_code)
def get_language_from_path(path, strict=False):
"""
Return the language code if there's a valid language code found in `path`.
If `strict` is False (the default), look for a country-specific variant
when neither the language code nor its generic variant is found.
"""
regex_match = language_code_prefix_re.match(path)
if not regex_match:
return None
lang_code = regex_match.group(1)
try:
return get_supported_language_variant(lang_code, strict=strict)
except LookupError:
return None
def get_language_from_request(request, check_path=False):
"""
Analyze the request to find what language the user wants the system to
show. Only languages listed in settings.LANGUAGES are taken into account.
If the user requests a sublanguage where we have a main language, we send
out the main language.
If check_path is True, the URL path prefix will be checked for a language
code, otherwise this is skipped for backwards compatibility.
"""
if check_path:
lang_code = get_language_from_path(request.path_info)
if lang_code is not None:
return lang_code
supported_lang_codes = get_languages()
if hasattr(request, 'session'):
lang_code = request.session.get(LANGUAGE_SESSION_KEY)
if lang_code in supported_lang_codes and lang_code is not None and check_for_language(lang_code):
return lang_code
lang_code = request.COOKIES.get(settings.LANGUAGE_COOKIE_NAME)
try:
return get_supported_language_variant(lang_code)
except LookupError:
pass
accept = request.META.get('HTTP_ACCEPT_LANGUAGE', '')
for accept_lang, unused in parse_accept_lang_header(accept):
if accept_lang == '*':
break
if not language_code_re.search(accept_lang):
continue
try:
return get_supported_language_variant(accept_lang)
except LookupError:
continue
try:
return get_supported_language_variant(settings.LANGUAGE_CODE)
except LookupError:
return settings.LANGUAGE_CODE
@functools.lru_cache(maxsize=1000)
def parse_accept_lang_header(lang_string):
"""
Parse the lang_string, which is the body of an HTTP Accept-Language
header, and return a tuple of (lang, q-value), ordered by 'q' values.
Return an empty tuple if there are any format errors in lang_string.
"""
result = []
pieces = accept_language_re.split(lang_string.lower())
if pieces[-1]:
return ()
for i in range(0, len(pieces) - 1, 3):
first, lang, priority = pieces[i:i + 3]
if first:
return ()
if priority:
priority = float(priority)
else:
priority = 1.0
result.append((lang, priority))
result.sort(key=lambda k: k[1], reverse=True)
return tuple(result)
|
11a1be74fadbd1b4240c9cfee435f9d8bc98fb0793d95c7295a8ad5ba6d486d9 | """
Internationalization support.
"""
import re
from contextlib import ContextDecorator
from django.utils.functional import lazy
__all__ = [
'activate', 'deactivate', 'override', 'deactivate_all',
'get_language', 'get_language_from_request',
'get_language_info', 'get_language_bidi',
'check_for_language', 'to_language', 'to_locale', 'templatize',
'gettext', 'gettext_lazy', 'gettext_noop',
'ugettext', 'ugettext_lazy', 'ugettext_noop',
'ngettext', 'ngettext_lazy',
'ungettext', 'ungettext_lazy',
'pgettext', 'pgettext_lazy',
'npgettext', 'npgettext_lazy',
'LANGUAGE_SESSION_KEY',
]
LANGUAGE_SESSION_KEY = '_language'
class TranslatorCommentWarning(SyntaxWarning):
pass
# Here be dragons, so a short explanation of the logic won't hurt:
# We are trying to solve two problems: (1) access settings, in particular
# settings.USE_I18N, as late as possible, so that modules can be imported
# without having to first configure Django, and (2) if some other code creates
# a reference to one of these functions, don't break that reference when we
# replace the functions with their real counterparts (once we do access the
# settings).
class Trans:
"""
The purpose of this class is to store the actual translation function upon
receiving the first call to that function. After this is done, changes to
USE_I18N will have no effect to which function is served upon request. If
your tests rely on changing USE_I18N, you can delete all the functions
from _trans.__dict__.
Note that storing the function with setattr will have a noticeable
performance effect, as access to the function goes the normal path,
instead of using __getattr__.
"""
def __getattr__(self, real_name):
from django.conf import settings
if settings.USE_I18N:
from django.utils.translation import trans_real as trans
else:
from django.utils.translation import trans_null as trans
setattr(self, real_name, getattr(trans, real_name))
return getattr(trans, real_name)
_trans = Trans()
# The Trans class is no more needed, so remove it from the namespace.
del Trans
def gettext_noop(message):
return _trans.gettext_noop(message)
ugettext_noop = gettext_noop
def gettext(message):
return _trans.gettext(message)
# An alias since Django 2.0
ugettext = gettext
def ngettext(singular, plural, number):
return _trans.ngettext(singular, plural, number)
# An alias since Django 2.0
ungettext = ngettext
def pgettext(context, message):
return _trans.pgettext(context, message)
def npgettext(context, singular, plural, number):
return _trans.npgettext(context, singular, plural, number)
gettext_lazy = ugettext_lazy = lazy(gettext, str)
pgettext_lazy = lazy(pgettext, str)
def lazy_number(func, resultclass, number=None, **kwargs):
if isinstance(number, int):
kwargs['number'] = number
proxy = lazy(func, resultclass)(**kwargs)
else:
original_kwargs = kwargs.copy()
class NumberAwareString(resultclass):
def __bool__(self):
return bool(kwargs['singular'])
def __mod__(self, rhs):
if isinstance(rhs, dict) and number:
try:
number_value = rhs[number]
except KeyError:
raise KeyError(
"Your dictionary lacks key '%s\'. Please provide "
"it, because it is required to determine whether "
"string is singular or plural." % number
)
else:
number_value = rhs
kwargs['number'] = number_value
translated = func(**kwargs)
try:
translated = translated % rhs
except TypeError:
# String doesn't contain a placeholder for the number.
pass
return translated
proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs)
proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs))
return proxy
def _lazy_number_unpickle(func, resultclass, number, kwargs):
return lazy_number(func, resultclass, number=number, **kwargs)
def ngettext_lazy(singular, plural, number=None):
return lazy_number(ngettext, str, singular=singular, plural=plural, number=number)
# An alias since Django 2.0
ungettext_lazy = ngettext_lazy
def npgettext_lazy(context, singular, plural, number=None):
return lazy_number(npgettext, str, context=context, singular=singular, plural=plural, number=number)
def activate(language):
return _trans.activate(language)
def deactivate():
return _trans.deactivate()
class override(ContextDecorator):
def __init__(self, language, deactivate=False):
self.language = language
self.deactivate = deactivate
def __enter__(self):
self.old_language = get_language()
if self.language is not None:
activate(self.language)
else:
deactivate_all()
def __exit__(self, exc_type, exc_value, traceback):
if self.old_language is None:
deactivate_all()
elif self.deactivate:
deactivate()
else:
activate(self.old_language)
def get_language():
return _trans.get_language()
def get_language_bidi():
return _trans.get_language_bidi()
def check_for_language(lang_code):
return _trans.check_for_language(lang_code)
def to_language(locale):
"""Turn a locale name (en_US) into a language name (en-us)."""
p = locale.find('_')
if p >= 0:
return locale[:p].lower() + '-' + locale[p + 1:].lower()
else:
return locale.lower()
def to_locale(language):
"""Turn a language name (en-us) into a locale name (en_US)."""
language = language.lower()
parts = language.split('-')
try:
country = parts[1]
except IndexError:
return language
# A language with > 2 characters after the dash only has its first
# character after the dash capitalized; e.g. sr-latn becomes sr_Latn.
# A language with 2 characters after the dash has both characters
# capitalized; e.g. en-us becomes en_US.
parts[1] = country.title() if len(country) > 2 else country.upper()
return parts[0] + '_' + '-'.join(parts[1:])
def get_language_from_request(request, check_path=False):
return _trans.get_language_from_request(request, check_path)
def get_language_from_path(path):
return _trans.get_language_from_path(path)
def get_supported_language_variant(lang_code, *, strict=False):
return _trans.get_supported_language_variant(lang_code, strict)
def templatize(src, **kwargs):
from .template import templatize
return templatize(src, **kwargs)
def deactivate_all():
return _trans.deactivate_all()
def get_language_info(lang_code):
from django.conf.locale import LANG_INFO
try:
lang_info = LANG_INFO[lang_code]
if 'fallback' in lang_info and 'name' not in lang_info:
info = get_language_info(lang_info['fallback'][0])
else:
info = lang_info
except KeyError:
if '-' not in lang_code:
raise KeyError("Unknown language code %s." % lang_code)
generic_lang_code = lang_code.split('-')[0]
try:
info = LANG_INFO[generic_lang_code]
except KeyError:
raise KeyError("Unknown language code %s and %s." % (lang_code, generic_lang_code))
if info:
info['name_translated'] = gettext_lazy(info['name'])
return info
trim_whitespace_re = re.compile(r'\s*\n\s*')
def trim_whitespace(s):
return trim_whitespace_re.sub(' ', s.strip())
|
601e05fbe6d88d3660a3b305621105c57408c4b9591c4b46775eb15b00d58add | import re
import warnings
from io import StringIO
from django.template.base import TRANSLATOR_COMMENT_MARK, Lexer, TokenType
from . import TranslatorCommentWarning, trim_whitespace
dot_re = re.compile(r'\S')
def blankout(src, char):
"""
Change every non-whitespace character to the given char.
Used in the templatize function.
"""
return dot_re.sub(char, src)
context_re = re.compile(r"""^\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?'))\s*""")
inline_re = re.compile(
# Match the trans 'some text' part
r"""^\s*trans\s+((?:"[^"]*?")|(?:'[^']*?'))"""
# Match and ignore optional filters
r"""(?:\s*\|\s*[^\s:]+(?::(?:[^\s'":]+|(?:"[^"]*?")|(?:'[^']*?')))?)*"""
# Match the optional context part
r"""(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?\s*"""
)
block_re = re.compile(r"""^\s*blocktrans(\s+.*context\s+((?:"[^"]*?")|(?:'[^']*?')))?(?:\s+|$)""")
endblock_re = re.compile(r"""^\s*endblocktrans$""")
plural_re = re.compile(r"""^\s*plural$""")
constant_re = re.compile(r"""_\(((?:".*?")|(?:'.*?'))\)""")
def templatize(src, origin=None):
"""
Turn a Django template into something that is understood by xgettext. It
does so by translating the Django translation tags into standard gettext
function invocations.
"""
out = StringIO('')
message_context = None
intrans = False
inplural = False
trimmed = False
singular = []
plural = []
incomment = False
comment = []
lineno_comment_map = {}
comment_lineno_cache = None
# Adding the u prefix allows gettext to recognize the string (#26093).
raw_prefix = 'u'
def join_tokens(tokens, trim=False):
message = ''.join(tokens)
if trim:
message = trim_whitespace(message)
return message
for t in Lexer(src).tokenize():
if incomment:
if t.token_type == TokenType.BLOCK and t.contents == 'endcomment':
content = ''.join(comment)
translators_comment_start = None
for lineno, line in enumerate(content.splitlines(True)):
if line.lstrip().startswith(TRANSLATOR_COMMENT_MARK):
translators_comment_start = lineno
for lineno, line in enumerate(content.splitlines(True)):
if translators_comment_start is not None and lineno >= translators_comment_start:
out.write(' # %s' % line)
else:
out.write(' #\n')
incomment = False
comment = []
else:
comment.append(t.contents)
elif intrans:
if t.token_type == TokenType.BLOCK:
endbmatch = endblock_re.match(t.contents)
pluralmatch = plural_re.match(t.contents)
if endbmatch:
if inplural:
if message_context:
out.write(' npgettext({p}{!r}, {p}{!r}, {p}{!r},count) '.format(
message_context,
join_tokens(singular, trimmed),
join_tokens(plural, trimmed),
p=raw_prefix,
))
else:
out.write(' ngettext({p}{!r}, {p}{!r}, count) '.format(
join_tokens(singular, trimmed),
join_tokens(plural, trimmed),
p=raw_prefix,
))
for part in singular:
out.write(blankout(part, 'S'))
for part in plural:
out.write(blankout(part, 'P'))
else:
if message_context:
out.write(' pgettext({p}{!r}, {p}{!r}) '.format(
message_context,
join_tokens(singular, trimmed),
p=raw_prefix,
))
else:
out.write(' gettext({p}{!r}) '.format(
join_tokens(singular, trimmed),
p=raw_prefix,
))
for part in singular:
out.write(blankout(part, 'S'))
message_context = None
intrans = False
inplural = False
singular = []
plural = []
elif pluralmatch:
inplural = True
else:
filemsg = ''
if origin:
filemsg = 'file %s, ' % origin
raise SyntaxError(
"Translation blocks must not include other block tags: "
"%s (%sline %d)" % (t.contents, filemsg, t.lineno)
)
elif t.token_type == TokenType.VAR:
if inplural:
plural.append('%%(%s)s' % t.contents)
else:
singular.append('%%(%s)s' % t.contents)
elif t.token_type == TokenType.TEXT:
contents = t.contents.replace('%', '%%')
if inplural:
plural.append(contents)
else:
singular.append(contents)
else:
# Handle comment tokens (`{# ... #}`) plus other constructs on
# the same line:
if comment_lineno_cache is not None:
cur_lineno = t.lineno + t.contents.count('\n')
if comment_lineno_cache == cur_lineno:
if t.token_type != TokenType.COMMENT:
for c in lineno_comment_map[comment_lineno_cache]:
filemsg = ''
if origin:
filemsg = 'file %s, ' % origin
warn_msg = (
"The translator-targeted comment '%s' "
"(%sline %d) was ignored, because it wasn't "
"the last item on the line."
) % (c, filemsg, comment_lineno_cache)
warnings.warn(warn_msg, TranslatorCommentWarning)
lineno_comment_map[comment_lineno_cache] = []
else:
out.write('# %s' % ' | '.join(lineno_comment_map[comment_lineno_cache]))
comment_lineno_cache = None
if t.token_type == TokenType.BLOCK:
imatch = inline_re.match(t.contents)
bmatch = block_re.match(t.contents)
cmatches = constant_re.findall(t.contents)
if imatch:
g = imatch.group(1)
if g[0] == '"':
g = g.strip('"')
elif g[0] == "'":
g = g.strip("'")
g = g.replace('%', '%%')
if imatch.group(2):
# A context is provided
context_match = context_re.match(imatch.group(2))
message_context = context_match.group(1)
if message_context[0] == '"':
message_context = message_context.strip('"')
elif message_context[0] == "'":
message_context = message_context.strip("'")
out.write(' pgettext({p}{!r}, {p}{!r}) '.format(
message_context, g, p=raw_prefix
))
message_context = None
else:
out.write(' gettext({p}{!r}) '.format(g, p=raw_prefix))
elif bmatch:
for fmatch in constant_re.findall(t.contents):
out.write(' _(%s) ' % fmatch)
if bmatch.group(1):
# A context is provided
context_match = context_re.match(bmatch.group(1))
message_context = context_match.group(1)
if message_context[0] == '"':
message_context = message_context.strip('"')
elif message_context[0] == "'":
message_context = message_context.strip("'")
intrans = True
inplural = False
trimmed = 'trimmed' in t.split_contents()
singular = []
plural = []
elif cmatches:
for cmatch in cmatches:
out.write(' _(%s) ' % cmatch)
elif t.contents == 'comment':
incomment = True
else:
out.write(blankout(t.contents, 'B'))
elif t.token_type == TokenType.VAR:
parts = t.contents.split('|')
cmatch = constant_re.match(parts[0])
if cmatch:
out.write(' _(%s) ' % cmatch.group(1))
for p in parts[1:]:
if p.find(':_(') >= 0:
out.write(' %s ' % p.split(':', 1)[1])
else:
out.write(blankout(p, 'F'))
elif t.token_type == TokenType.COMMENT:
if t.contents.lstrip().startswith(TRANSLATOR_COMMENT_MARK):
lineno_comment_map.setdefault(t.lineno, []).append(t.contents)
comment_lineno_cache = t.lineno
else:
out.write(blankout(t.contents, 'X'))
return out.getvalue()
|
ca9f366c7b79a2aa8bf796793c5a1809978434eba5c73a7e22a326916cf497d6 | # These are versions of the functions in django.utils.translation.trans_real
# that don't actually do anything. This is purely for performance, so that
# settings.USE_I18N = False can use this module rather than trans_real.py.
from django.conf import settings
def gettext(message):
return message
gettext_noop = gettext_lazy = _ = gettext
def ngettext(singular, plural, number):
if number == 1:
return singular
return plural
ngettext_lazy = ngettext
def pgettext(context, message):
return gettext(message)
def npgettext(context, singular, plural, number):
return ngettext(singular, plural, number)
def activate(x):
return None
def deactivate():
return None
deactivate_all = deactivate
def get_language():
return settings.LANGUAGE_CODE
def get_language_bidi():
return settings.LANGUAGE_CODE in settings.LANGUAGES_BIDI
def check_for_language(x):
return True
def get_language_from_request(request, check_path=False):
return settings.LANGUAGE_CODE
def get_language_from_path(request):
return None
def get_supported_language_variant(lang_code, strict=False):
if lang_code == settings.LANGUAGE_CODE:
return lang_code
else:
raise LookupError(lang_code)
|
c376bce04017597d76c3b1750b2c4843f945893c31152ef17f7ac211c9d4ab27 | """
Wrapper for loading templates from "templates" directories in INSTALLED_APPS
packages.
"""
from django.template.utils import get_app_template_dirs
from .filesystem import Loader as FilesystemLoader
class Loader(FilesystemLoader):
def get_dirs(self):
return get_app_template_dirs('templates')
|
92f8e637e507c5d77a3f08247b1c3b2072f461e2508175dbbb3fed763e5c88a7 | from django.template import Template, TemplateDoesNotExist
class Loader:
def __init__(self, engine):
self.engine = engine
def get_template(self, template_name, skip=None):
"""
Call self.get_template_sources() and return a Template object for
the first template matching template_name. If skip is provided, ignore
template origins in skip. This is used to avoid recursion during
template extending.
"""
tried = []
for origin in self.get_template_sources(template_name):
if skip is not None and origin in skip:
tried.append((origin, 'Skipped'))
continue
try:
contents = self.get_contents(origin)
except TemplateDoesNotExist:
tried.append((origin, 'Source does not exist'))
continue
else:
return Template(
contents, origin, origin.template_name, self.engine,
)
raise TemplateDoesNotExist(template_name, tried=tried)
def get_template_sources(self, template_name):
"""
An iterator that yields possible matching template paths for a
template name.
"""
raise NotImplementedError(
'subclasses of Loader must provide a get_template_sources() method'
)
def reset(self):
"""
Reset any state maintained by the loader instance (e.g. cached
templates or cached loader modules).
"""
pass
|
3964e723059b563f9377956b3a42b0d46ffaa48bb3d559e1e4279d64de609725 | """
Wrapper for loading templates from the filesystem.
"""
from django.core.exceptions import SuspiciousFileOperation
from django.template import Origin, TemplateDoesNotExist
from django.utils._os import safe_join
from .base import Loader as BaseLoader
class Loader(BaseLoader):
def __init__(self, engine, dirs=None):
super().__init__(engine)
self.dirs = dirs
def get_dirs(self):
return self.dirs if self.dirs is not None else self.engine.dirs
def get_contents(self, origin):
try:
with open(origin.name, encoding=self.engine.file_charset) as fp:
return fp.read()
except FileNotFoundError:
raise TemplateDoesNotExist(origin)
def get_template_sources(self, template_name):
"""
Return an Origin object pointing to an absolute path in each directory
in template_dirs. For security reasons, if a path doesn't lie inside
one of the template_dirs it is excluded from the result set.
"""
for template_dir in self.get_dirs():
try:
name = safe_join(template_dir, template_name)
except SuspiciousFileOperation:
# The joined path was located outside of this template_dir
# (it might be inside another one, so this isn't fatal).
continue
yield Origin(
name=name,
template_name=template_name,
loader=self,
)
|
b5b91211a30ec97f58b36f68a53a48f16ba2e7d6de3b6e4524e1c79b630fe95a | """
Wrapper class that takes a list of template loaders as an argument and attempts
to load templates from them in order, caching the result.
"""
import hashlib
from django.template import TemplateDoesNotExist
from django.template.backends.django import copy_exception
from .base import Loader as BaseLoader
class Loader(BaseLoader):
def __init__(self, engine, loaders):
self.template_cache = {}
self.get_template_cache = {}
self.loaders = engine.get_template_loaders(loaders)
super().__init__(engine)
def get_contents(self, origin):
return origin.loader.get_contents(origin)
def get_template(self, template_name, skip=None):
"""
Perform the caching that gives this loader its name. Often many of the
templates attempted will be missing, so memory use is of concern here.
To keep it in check, caching behavior is a little complicated when a
template is not found. See ticket #26306 for more details.
With template debugging disabled, cache the TemplateDoesNotExist class
for every missing template and raise a new instance of it after
fetching it from the cache.
With template debugging enabled, a unique TemplateDoesNotExist object
is cached for each missing template to preserve debug data. When
raising an exception, Python sets __traceback__, __context__, and
__cause__ attributes on it. Those attributes can contain references to
all sorts of objects up the call chain and caching them creates a
memory leak. Thus, unraised copies of the exceptions are cached and
copies of those copies are raised after they're fetched from the cache.
"""
key = self.cache_key(template_name, skip)
cached = self.get_template_cache.get(key)
if cached:
if isinstance(cached, type) and issubclass(cached, TemplateDoesNotExist):
raise cached(template_name)
elif isinstance(cached, TemplateDoesNotExist):
raise copy_exception(cached)
return cached
try:
template = super().get_template(template_name, skip)
except TemplateDoesNotExist as e:
self.get_template_cache[key] = copy_exception(e) if self.engine.debug else TemplateDoesNotExist
raise
else:
self.get_template_cache[key] = template
return template
def get_template_sources(self, template_name):
for loader in self.loaders:
yield from loader.get_template_sources(template_name)
def cache_key(self, template_name, skip=None):
"""
Generate a cache key for the template name, dirs, and skip.
If skip is provided, only origins that match template_name are included
in the cache key. This ensures each template is only parsed and cached
once if contained in different extend chains like:
x -> a -> a
y -> a -> a
z -> a -> a
"""
dirs_prefix = ''
skip_prefix = ''
if skip:
matching = [origin.name for origin in skip if origin.template_name == template_name]
if matching:
skip_prefix = self.generate_hash(matching)
return '-'.join(s for s in (str(template_name), skip_prefix, dirs_prefix) if s)
def generate_hash(self, values):
return hashlib.sha1('|'.join(values).encode()).hexdigest()
def reset(self):
"Empty the template cache."
self.template_cache.clear()
self.get_template_cache.clear()
|
f1c05823cc0f38e9c8c7fdefedf0b98decc0ffaa492ea82a39b78bc075d024aa | """
Wrapper for loading templates from a plain Python dict.
"""
from django.template import Origin, TemplateDoesNotExist
from .base import Loader as BaseLoader
class Loader(BaseLoader):
def __init__(self, engine, templates_dict):
self.templates_dict = templates_dict
super().__init__(engine)
def get_contents(self, origin):
try:
return self.templates_dict[origin.name]
except KeyError:
raise TemplateDoesNotExist(origin)
def get_template_sources(self, template_name):
yield Origin(
name=template_name,
template_name=template_name,
loader=self,
)
|
3fc76f3a6429a49f18319e7f5f2389183ceca5b40c34657cd86c4be48c2b3053 | from django.core.exceptions import (
ImproperlyConfigured, SuspiciousFileOperation,
)
from django.template.utils import get_app_template_dirs
from django.utils._os import safe_join
from django.utils.functional import cached_property
class BaseEngine:
# Core methods: engines have to provide their own implementation
# (except for from_string which is optional).
def __init__(self, params):
"""
Initialize the template engine.
`params` is a dict of configuration settings.
"""
params = params.copy()
self.name = params.pop('NAME')
self.dirs = list(params.pop('DIRS'))
self.app_dirs = params.pop('APP_DIRS')
if params:
raise ImproperlyConfigured(
"Unknown parameters: {}".format(", ".join(params)))
@property
def app_dirname(self):
raise ImproperlyConfigured(
"{} doesn't support loading templates from installed "
"applications.".format(self.__class__.__name__))
def from_string(self, template_code):
"""
Create and return a template for the given source code.
This method is optional.
"""
raise NotImplementedError(
"subclasses of BaseEngine should provide "
"a from_string() method")
def get_template(self, template_name):
"""
Load and return a template for the given name.
Raise TemplateDoesNotExist if no such template exists.
"""
raise NotImplementedError(
"subclasses of BaseEngine must provide "
"a get_template() method")
# Utility methods: they are provided to minimize code duplication and
# security issues in third-party backends.
@cached_property
def template_dirs(self):
"""
Return a list of directories to search for templates.
"""
# Immutable return value because it's cached and shared by callers.
template_dirs = tuple(self.dirs)
if self.app_dirs:
template_dirs += get_app_template_dirs(self.app_dirname)
return template_dirs
def iter_template_filenames(self, template_name):
"""
Iterate over candidate files for template_name.
Ignore files that don't lie inside configured template dirs to avoid
directory traversal attacks.
"""
for template_dir in self.template_dirs:
try:
yield safe_join(template_dir, template_name)
except SuspiciousFileOperation:
# The joined path was located outside of this template_dir
# (it might be inside another one, so this isn't fatal).
pass
|
e48c71d3ca227e78e9205a1dd6df4844927f4be5021a4ffe087ea84ee219a971 | from django.middleware.csrf import get_token
from django.utils.functional import lazy
from django.utils.html import format_html
from django.utils.safestring import SafeText
def csrf_input(request):
return format_html(
'<input type="hidden" name="csrfmiddlewaretoken" value="{}">',
get_token(request))
csrf_input_lazy = lazy(csrf_input, SafeText, str)
csrf_token_lazy = lazy(get_token, str)
|
365df5dd2c57d6bc44d45fb90070a58e07a3ad8a580b1f905c9a4d5244165d1e | import string
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.template import Origin, TemplateDoesNotExist
from django.utils.html import conditional_escape
from .base import BaseEngine
from .utils import csrf_input_lazy, csrf_token_lazy
class TemplateStrings(BaseEngine):
app_dirname = 'template_strings'
def __init__(self, params):
params = params.copy()
options = params.pop('OPTIONS').copy()
if options:
raise ImproperlyConfigured(
"Unknown options: {}".format(", ".join(options)))
super().__init__(params)
def from_string(self, template_code):
return Template(template_code)
def get_template(self, template_name):
tried = []
for template_file in self.iter_template_filenames(template_name):
try:
with open(template_file, encoding=settings.FILE_CHARSET) as fp:
template_code = fp.read()
except FileNotFoundError:
tried.append((
Origin(template_file, template_name, self),
'Source does not exist',
))
else:
return Template(template_code)
raise TemplateDoesNotExist(template_name, tried=tried, backend=self)
class Template(string.Template):
def render(self, context=None, request=None):
if context is None:
context = {}
else:
context = {k: conditional_escape(v) for k, v in context.items()}
if request is not None:
context['csrf_input'] = csrf_input_lazy(request)
context['csrf_token'] = csrf_token_lazy(request)
return self.safe_substitute(context)
|
6f1f03700d8faaacc399c81e818d75a66e448660ff8164d32dab86a3dd6298be | import jinja2
from django.conf import settings
from django.template import TemplateDoesNotExist, TemplateSyntaxError
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from .base import BaseEngine
class Jinja2(BaseEngine):
app_dirname = 'jinja2'
def __init__(self, params):
params = params.copy()
options = params.pop('OPTIONS').copy()
super().__init__(params)
self.context_processors = options.pop('context_processors', [])
environment = options.pop('environment', 'jinja2.Environment')
environment_cls = import_string(environment)
if 'loader' not in options:
options['loader'] = jinja2.FileSystemLoader(self.template_dirs)
options.setdefault('autoescape', True)
options.setdefault('auto_reload', settings.DEBUG)
options.setdefault('undefined',
jinja2.DebugUndefined if settings.DEBUG else jinja2.Undefined)
self.env = environment_cls(**options)
def from_string(self, template_code):
return Template(self.env.from_string(template_code), self)
def get_template(self, template_name):
try:
return Template(self.env.get_template(template_name), self)
except jinja2.TemplateNotFound as exc:
raise TemplateDoesNotExist(exc.name, backend=self) from exc
except jinja2.TemplateSyntaxError as exc:
new = TemplateSyntaxError(exc.args)
new.template_debug = get_exception_info(exc)
raise new from exc
@cached_property
def template_context_processors(self):
return [import_string(path) for path in self.context_processors]
class Template:
def __init__(self, template, backend):
self.template = template
self.backend = backend
self.origin = Origin(
name=template.filename, template_name=template.name,
)
def render(self, context=None, request=None):
from .utils import csrf_input_lazy, csrf_token_lazy
if context is None:
context = {}
if request is not None:
context['request'] = request
context['csrf_input'] = csrf_input_lazy(request)
context['csrf_token'] = csrf_token_lazy(request)
for context_processor in self.backend.template_context_processors:
context.update(context_processor(request))
return self.template.render(context)
class Origin:
"""
A container to hold debug information as described in the template API
documentation.
"""
def __init__(self, name, template_name):
self.name = name
self.template_name = template_name
def get_exception_info(exception):
"""
Format exception information for display on the debug page using the
structure described in the template API documentation.
"""
context_lines = 10
lineno = exception.lineno
lines = list(enumerate(exception.source.strip().split("\n"), start=1))
during = lines[lineno - 1][1]
total = len(lines)
top = max(0, lineno - context_lines - 1)
bottom = min(total, lineno + context_lines)
return {
'name': exception.filename,
'message': exception.message,
'source_lines': lines[top:bottom],
'line': lineno,
'before': '',
'during': during,
'after': '',
'total': total,
'top': top,
'bottom': bottom,
}
|
ff0df9d2d98700c48b3b0f9bda8f6b4745a7e985f740c9291e4929bdba3f1302 | from importlib import import_module
from pkgutil import walk_packages
from django.apps import apps
from django.conf import settings
from django.template import TemplateDoesNotExist
from django.template.context import make_context
from django.template.engine import Engine
from django.template.library import InvalidTemplateLibrary
from .base import BaseEngine
class DjangoTemplates(BaseEngine):
app_dirname = 'templates'
def __init__(self, params):
params = params.copy()
options = params.pop('OPTIONS').copy()
options.setdefault('autoescape', True)
options.setdefault('debug', settings.DEBUG)
options.setdefault('file_charset', settings.FILE_CHARSET)
libraries = options.get('libraries', {})
options['libraries'] = self.get_templatetag_libraries(libraries)
super().__init__(params)
self.engine = Engine(self.dirs, self.app_dirs, **options)
def from_string(self, template_code):
return Template(self.engine.from_string(template_code), self)
def get_template(self, template_name):
try:
return Template(self.engine.get_template(template_name), self)
except TemplateDoesNotExist as exc:
reraise(exc, self)
def get_templatetag_libraries(self, custom_libraries):
"""
Return a collation of template tag libraries from installed
applications and the supplied custom_libraries argument.
"""
libraries = get_installed_libraries()
libraries.update(custom_libraries)
return libraries
class Template:
def __init__(self, template, backend):
self.template = template
self.backend = backend
@property
def origin(self):
return self.template.origin
def render(self, context=None, request=None):
context = make_context(context, request, autoescape=self.backend.engine.autoescape)
try:
return self.template.render(context)
except TemplateDoesNotExist as exc:
reraise(exc, self.backend)
def copy_exception(exc, backend=None):
"""
Create a new TemplateDoesNotExist. Preserve its declared attributes and
template debug data but discard __traceback__, __context__, and __cause__
to make this object suitable for keeping around (in a cache, for example).
"""
backend = backend or exc.backend
new = exc.__class__(*exc.args, tried=exc.tried, backend=backend, chain=exc.chain)
if hasattr(exc, 'template_debug'):
new.template_debug = exc.template_debug
return new
def reraise(exc, backend):
"""
Reraise TemplateDoesNotExist while maintaining template debug information.
"""
new = copy_exception(exc, backend)
raise new from exc
def get_installed_libraries():
"""
Return the built-in template tag libraries and those from installed
applications. Libraries are stored in a dictionary where keys are the
individual module names, not the full module paths. Example:
django.templatetags.i18n is stored as i18n.
"""
libraries = {}
candidates = ['django.templatetags']
candidates.extend(
'%s.templatetags' % app_config.name
for app_config in apps.get_app_configs())
for candidate in candidates:
try:
pkg = import_module(candidate)
except ImportError:
# No templatetags package defined. This is safe to ignore.
continue
if hasattr(pkg, '__path__'):
for name in get_package_libraries(pkg):
libraries[name[len(candidate) + 1:]] = name
return libraries
def get_package_libraries(pkg):
"""
Recursively yield template tag libraries defined in submodules of a
package.
"""
for entry in walk_packages(pkg.__path__, pkg.__name__ + '.'):
try:
module = import_module(entry[1])
except ImportError as e:
raise InvalidTemplateLibrary(
"Invalid template library specified. ImportError raised when "
"trying to load '%s': %s" % (entry[1], e)
)
if hasattr(module, 'register'):
yield entry[1]
|
29f1569a594d5b478a225a827ec10dba93c13c71d7b1c61b2448bcdbb9f14642 | from django.apps.registry import apps as global_apps
from django.db import migrations, router
from .exceptions import InvalidMigrationPlan
from .loader import MigrationLoader
from .recorder import MigrationRecorder
from .state import ProjectState
class MigrationExecutor:
"""
End-to-end migration execution - load migrations and run them up or down
to a specified set of targets.
"""
def __init__(self, connection, progress_callback=None):
self.connection = connection
self.loader = MigrationLoader(self.connection)
self.recorder = MigrationRecorder(self.connection)
self.progress_callback = progress_callback
def migration_plan(self, targets, clean_start=False):
"""
Given a set of targets, return a list of (Migration instance, backwards?).
"""
plan = []
if clean_start:
applied = set()
else:
applied = set(self.loader.applied_migrations)
for target in targets:
# If the target is (app_label, None), that means unmigrate everything
if target[1] is None:
for root in self.loader.graph.root_nodes():
if root[0] == target[0]:
for migration in self.loader.graph.backwards_plan(root):
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
applied.remove(migration)
# If the migration is already applied, do backwards mode,
# otherwise do forwards mode.
elif target in applied:
# Don't migrate backwards all the way to the target node (that
# may roll back dependencies in other apps that don't need to
# be rolled back); instead roll back through target's immediate
# child(ren) in the same app, and no further.
next_in_app = sorted(
n for n in
self.loader.graph.node_map[target].children
if n[0] == target[0]
)
for node in next_in_app:
for migration in self.loader.graph.backwards_plan(node):
if migration in applied:
plan.append((self.loader.graph.nodes[migration], True))
applied.remove(migration)
else:
for migration in self.loader.graph.forwards_plan(target):
if migration not in applied:
plan.append((self.loader.graph.nodes[migration], False))
applied.add(migration)
return plan
def _create_project_state(self, with_applied_migrations=False):
"""
Create a project state including all the applications without
migrations and applied migrations if with_applied_migrations=True.
"""
state = ProjectState(real_apps=list(self.loader.unmigrated_apps))
if with_applied_migrations:
# Create the forwards plan Django would follow on an empty database
full_plan = self.migration_plan(self.loader.graph.leaf_nodes(), clean_start=True)
applied_migrations = {
self.loader.graph.nodes[key] for key in self.loader.applied_migrations
if key in self.loader.graph.nodes
}
for migration, _ in full_plan:
if migration in applied_migrations:
migration.mutate_state(state, preserve=False)
return state
def migrate(self, targets, plan=None, state=None, fake=False, fake_initial=False):
"""
Migrate the database up to the given targets.
Django first needs to create all project states before a migration is
(un)applied and in a second step run all the database operations.
"""
# The django_migrations table must be present to record applied
# migrations.
self.recorder.ensure_schema()
if plan is None:
plan = self.migration_plan(targets)
# Create the forwards plan Django would follow on an empty database
full_plan = self.migration_plan(self.loader.graph.leaf_nodes(), clean_start=True)
all_forwards = all(not backwards for mig, backwards in plan)
all_backwards = all(backwards for mig, backwards in plan)
if not plan:
if state is None:
# The resulting state should include applied migrations.
state = self._create_project_state(with_applied_migrations=True)
elif all_forwards == all_backwards:
# This should only happen if there's a mixed plan
raise InvalidMigrationPlan(
"Migration plans with both forwards and backwards migrations "
"are not supported. Please split your migration process into "
"separate plans of only forwards OR backwards migrations.",
plan
)
elif all_forwards:
if state is None:
# The resulting state should still include applied migrations.
state = self._create_project_state(with_applied_migrations=True)
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
else:
# No need to check for `elif all_backwards` here, as that condition
# would always evaluate to true.
state = self._migrate_all_backwards(plan, full_plan, fake=fake)
self.check_replacements()
return state
def _migrate_all_forwards(self, state, plan, full_plan, fake, fake_initial):
"""
Take a list of 2-tuples of the form (migration instance, False) and
apply them in the order they occur in the full_plan.
"""
migrations_to_run = {m[0] for m in plan}
for migration, _ in full_plan:
if not migrations_to_run:
# We remove every migration that we applied from these sets so
# that we can bail out once the last migration has been applied
# and don't always run until the very end of the migration
# process.
break
if migration in migrations_to_run:
if 'apps' not in state.__dict__:
if self.progress_callback:
self.progress_callback("render_start")
state.apps # Render all -- performance critical
if self.progress_callback:
self.progress_callback("render_success")
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
migrations_to_run.remove(migration)
return state
def _migrate_all_backwards(self, plan, full_plan, fake):
"""
Take a list of 2-tuples of the form (migration instance, True) and
unapply them in reverse order they occur in the full_plan.
Since unapplying a migration requires the project state prior to that
migration, Django will compute the migration states before each of them
in a first run over the plan and then unapply them in a second run over
the plan.
"""
migrations_to_run = {m[0] for m in plan}
# Holds all migration states prior to the migrations being unapplied
states = {}
state = self._create_project_state()
applied_migrations = {
self.loader.graph.nodes[key] for key in self.loader.applied_migrations
if key in self.loader.graph.nodes
}
if self.progress_callback:
self.progress_callback("render_start")
for migration, _ in full_plan:
if not migrations_to_run:
# We remove every migration that we applied from this set so
# that we can bail out once the last migration has been applied
# and don't always run until the very end of the migration
# process.
break
if migration in migrations_to_run:
if 'apps' not in state.__dict__:
state.apps # Render all -- performance critical
# The state before this migration
states[migration] = state
# The old state keeps as-is, we continue with the new state
state = migration.mutate_state(state, preserve=True)
migrations_to_run.remove(migration)
elif migration in applied_migrations:
# Only mutate the state if the migration is actually applied
# to make sure the resulting state doesn't include changes
# from unrelated migrations.
migration.mutate_state(state, preserve=False)
if self.progress_callback:
self.progress_callback("render_success")
for migration, _ in plan:
self.unapply_migration(states[migration], migration, fake=fake)
applied_migrations.remove(migration)
# Generate the post migration state by starting from the state before
# the last migration is unapplied and mutating it to include all the
# remaining applied migrations.
last_unapplied_migration = plan[-1][0]
state = states[last_unapplied_migration]
for index, (migration, _) in enumerate(full_plan):
if migration == last_unapplied_migration:
for migration, _ in full_plan[index:]:
if migration in applied_migrations:
migration.mutate_state(state, preserve=False)
break
return state
def collect_sql(self, plan):
"""
Take a migration plan and return a list of collected SQL statements
that represent the best-efforts version of that plan.
"""
statements = []
state = None
for migration, backwards in plan:
with self.connection.schema_editor(collect_sql=True, atomic=migration.atomic) as schema_editor:
if state is None:
state = self.loader.project_state((migration.app_label, migration.name), at_end=False)
if not backwards:
state = migration.apply(state, schema_editor, collect_sql=True)
else:
state = migration.unapply(state, schema_editor, collect_sql=True)
statements.extend(schema_editor.collected_sql)
return statements
def apply_migration(self, state, migration, fake=False, fake_initial=False):
"""Run a migration forwards."""
if self.progress_callback:
self.progress_callback("apply_start", migration, fake)
if not fake:
if fake_initial:
# Test to see if this is an already-applied initial migration
applied, state = self.detect_soft_applied(state, migration)
if applied:
fake = True
if not fake:
# Alright, do it normally
with self.connection.schema_editor(atomic=migration.atomic) as schema_editor:
state = migration.apply(state, schema_editor)
# For replacement migrations, record individual statuses
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_applied(app_label, name)
else:
self.recorder.record_applied(migration.app_label, migration.name)
# Report progress
if self.progress_callback:
self.progress_callback("apply_success", migration, fake)
return state
def unapply_migration(self, state, migration, fake=False):
"""Run a migration backwards."""
if self.progress_callback:
self.progress_callback("unapply_start", migration, fake)
if not fake:
with self.connection.schema_editor(atomic=migration.atomic) as schema_editor:
state = migration.unapply(state, schema_editor)
# For replacement migrations, record individual statuses
if migration.replaces:
for app_label, name in migration.replaces:
self.recorder.record_unapplied(app_label, name)
else:
self.recorder.record_unapplied(migration.app_label, migration.name)
# Report progress
if self.progress_callback:
self.progress_callback("unapply_success", migration, fake)
return state
def check_replacements(self):
"""
Mark replacement migrations applied if their replaced set all are.
Do this unconditionally on every migrate, rather than just when
migrations are applied or unapplied, to correctly handle the case
when a new squash migration is pushed to a deployment that already had
all its replaced migrations applied. In this case no new migration will
be applied, but the applied state of the squashed migration must be
maintained.
"""
applied = self.recorder.applied_migrations()
for key, migration in self.loader.replacements.items():
all_applied = all(m in applied for m in migration.replaces)
if all_applied and key not in applied:
self.recorder.record_applied(*key)
def detect_soft_applied(self, project_state, migration):
"""
Test whether a migration has been implicitly applied - that the
tables or columns it would create exist. This is intended only for use
on initial migrations (as it only looks for CreateModel and AddField).
"""
def should_skip_detecting_model(migration, model):
"""
No need to detect tables for proxy models, unmanaged models, or
models that can't be migrated on the current database.
"""
return (
model._meta.proxy or not model._meta.managed or not
router.allow_migrate(
self.connection.alias, migration.app_label,
model_name=model._meta.model_name,
)
)
if migration.initial is None:
# Bail if the migration isn't the first one in its app
if any(app == migration.app_label for app, name in migration.dependencies):
return False, project_state
elif migration.initial is False:
# Bail if it's NOT an initial migration
return False, project_state
if project_state is None:
after_state = self.loader.project_state((migration.app_label, migration.name), at_end=True)
else:
after_state = migration.mutate_state(project_state)
apps = after_state.apps
found_create_model_migration = False
found_add_field_migration = False
with self.connection.cursor() as cursor:
existing_table_names = self.connection.introspection.table_names(cursor)
# Make sure all create model and add field operations are done
for operation in migration.operations:
if isinstance(operation, migrations.CreateModel):
model = apps.get_model(migration.app_label, operation.name)
if model._meta.swapped:
# We have to fetch the model to test with from the
# main app cache, as it's not a direct dependency.
model = global_apps.get_model(model._meta.swapped)
if should_skip_detecting_model(migration, model):
continue
if model._meta.db_table not in existing_table_names:
return False, project_state
found_create_model_migration = True
elif isinstance(operation, migrations.AddField):
model = apps.get_model(migration.app_label, operation.model_name)
if model._meta.swapped:
# We have to fetch the model to test with from the
# main app cache, as it's not a direct dependency.
model = global_apps.get_model(model._meta.swapped)
if should_skip_detecting_model(migration, model):
continue
table = model._meta.db_table
field = model._meta.get_field(operation.name)
# Handle implicit many-to-many tables created by AddField.
if field.many_to_many:
if field.remote_field.through._meta.db_table not in existing_table_names:
return False, project_state
else:
found_add_field_migration = True
continue
column_names = [
column.name for column in
self.connection.introspection.get_table_description(self.connection.cursor(), table)
]
if field.column not in column_names:
return False, project_state
found_add_field_migration = True
# If we get this far and we found at least one CreateModel or AddField migration,
# the migration is considered implicitly applied.
return (found_create_model_migration or found_add_field_migration), after_state
|
84c3dd431dafa79216b149e003dc6b1a25d082aaa3335d4f9d007f98af71a48d | def topological_sort_as_sets(dependency_graph):
"""
Variation of Kahn's algorithm (1962) that returns sets.
Take a dependency graph as a dictionary of node => dependencies.
Yield sets of items in topological order, where the first set contains
all nodes without dependencies, and each following set contains all
nodes that may depend on the nodes only in the previously yielded sets.
"""
todo = dependency_graph.copy()
while todo:
current = {node for node, deps in todo.items() if not deps}
if not current:
raise ValueError('Cyclic dependency in graph: {}'.format(
', '.join(repr(x) for x in todo.items())))
yield current
# remove current from todo's nodes & dependencies
todo = {node: (dependencies - current) for node, dependencies in
todo.items() if node not in current}
def stable_topological_sort(l, dependency_graph):
result = []
for layer in topological_sort_as_sets(dependency_graph):
for node in l:
if node in layer:
result.append(node)
return result
|
188ad83a71af46255fba40143b4094e233120df4086e22b2f6f2f4d259a6ce18 | import copy
from collections import OrderedDict
from contextlib import contextmanager
from django.apps import AppConfig
from django.apps.registry import Apps, apps as global_apps
from django.conf import settings
from django.db import models
from django.db.models.fields.proxy import OrderWrt
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
from django.db.models.options import DEFAULT_NAMES, normalize_together
from django.db.models.utils import make_model_tuple
from django.utils.functional import cached_property
from django.utils.module_loading import import_string
from django.utils.version import get_docs_version
from .exceptions import InvalidBasesError
def _get_app_label_and_model_name(model, app_label=''):
if isinstance(model, str):
split = model.split('.', 1)
return tuple(split) if len(split) == 2 else (app_label, split[0])
else:
return model._meta.app_label, model._meta.model_name
def _get_related_models(m):
"""Return all models that have a direct relationship to the given model."""
related_models = [
subclass for subclass in m.__subclasses__()
if issubclass(subclass, models.Model)
]
related_fields_models = set()
for f in m._meta.get_fields(include_parents=True, include_hidden=True):
if f.is_relation and f.related_model is not None and not isinstance(f.related_model, str):
related_fields_models.add(f.model)
related_models.append(f.related_model)
# Reverse accessors of foreign keys to proxy models are attached to their
# concrete proxied model.
opts = m._meta
if opts.proxy and m in related_fields_models:
related_models.append(opts.concrete_model)
return related_models
def get_related_models_tuples(model):
"""
Return a list of typical (app_label, model_name) tuples for all related
models for the given model.
"""
return {
(rel_mod._meta.app_label, rel_mod._meta.model_name)
for rel_mod in _get_related_models(model)
}
def get_related_models_recursive(model):
"""
Return all models that have a direct or indirect relationship
to the given model.
Relationships are either defined by explicit relational fields, like
ForeignKey, ManyToManyField or OneToOneField, or by inheriting from another
model (a superclass is related to its subclasses, but not vice versa). Note,
however, that a model inheriting from a concrete model is also related to
its superclass through the implicit *_ptr OneToOneField on the subclass.
"""
seen = set()
queue = _get_related_models(model)
for rel_mod in queue:
rel_app_label, rel_model_name = rel_mod._meta.app_label, rel_mod._meta.model_name
if (rel_app_label, rel_model_name) in seen:
continue
seen.add((rel_app_label, rel_model_name))
queue.extend(_get_related_models(rel_mod))
return seen - {(model._meta.app_label, model._meta.model_name)}
class ProjectState:
"""
Represent the entire project's overall state. This is the item that is
passed around - do it here rather than at the app level so that cross-app
FKs/etc. resolve properly.
"""
def __init__(self, models=None, real_apps=None):
self.models = models or {}
# Apps to include from main registry, usually unmigrated ones
self.real_apps = real_apps or []
self.is_delayed = False
def add_model(self, model_state):
app_label, model_name = model_state.app_label, model_state.name_lower
self.models[(app_label, model_name)] = model_state
if 'apps' in self.__dict__: # hasattr would cache the property
self.reload_model(app_label, model_name)
def remove_model(self, app_label, model_name):
del self.models[app_label, model_name]
if 'apps' in self.__dict__: # hasattr would cache the property
self.apps.unregister_model(app_label, model_name)
# Need to do this explicitly since unregister_model() doesn't clear
# the cache automatically (#24513)
self.apps.clear_cache()
def _find_reload_model(self, app_label, model_name, delay=False):
if delay:
self.is_delayed = True
related_models = set()
try:
old_model = self.apps.get_model(app_label, model_name)
except LookupError:
pass
else:
# Get all relations to and from the old model before reloading,
# as _meta.apps may change
if delay:
related_models = get_related_models_tuples(old_model)
else:
related_models = get_related_models_recursive(old_model)
# Get all outgoing references from the model to be rendered
model_state = self.models[(app_label, model_name)]
# Directly related models are the models pointed to by ForeignKeys,
# OneToOneFields, and ManyToManyFields.
direct_related_models = set()
for name, field in model_state.fields:
if field.is_relation:
if field.remote_field.model == RECURSIVE_RELATIONSHIP_CONSTANT:
continue
rel_app_label, rel_model_name = _get_app_label_and_model_name(field.related_model, app_label)
direct_related_models.add((rel_app_label, rel_model_name.lower()))
# For all direct related models recursively get all related models.
related_models.update(direct_related_models)
for rel_app_label, rel_model_name in direct_related_models:
try:
rel_model = self.apps.get_model(rel_app_label, rel_model_name)
except LookupError:
pass
else:
if delay:
related_models.update(get_related_models_tuples(rel_model))
else:
related_models.update(get_related_models_recursive(rel_model))
# Include the model itself
related_models.add((app_label, model_name))
return related_models
def reload_model(self, app_label, model_name, delay=False):
if 'apps' in self.__dict__: # hasattr would cache the property
related_models = self._find_reload_model(app_label, model_name, delay)
self._reload(related_models)
def reload_models(self, models, delay=True):
if 'apps' in self.__dict__: # hasattr would cache the property
related_models = set()
for app_label, model_name in models:
related_models.update(self._find_reload_model(app_label, model_name, delay))
self._reload(related_models)
def _reload(self, related_models):
# Unregister all related models
with self.apps.bulk_update():
for rel_app_label, rel_model_name in related_models:
self.apps.unregister_model(rel_app_label, rel_model_name)
states_to_be_rendered = []
# Gather all models states of those models that will be rerendered.
# This includes:
# 1. All related models of unmigrated apps
for model_state in self.apps.real_models:
if (model_state.app_label, model_state.name_lower) in related_models:
states_to_be_rendered.append(model_state)
# 2. All related models of migrated apps
for rel_app_label, rel_model_name in related_models:
try:
model_state = self.models[rel_app_label, rel_model_name]
except KeyError:
pass
else:
states_to_be_rendered.append(model_state)
# Render all models
self.apps.render_multiple(states_to_be_rendered)
def clone(self):
"""Return an exact copy of this ProjectState."""
new_state = ProjectState(
models={k: v.clone() for k, v in self.models.items()},
real_apps=self.real_apps,
)
if 'apps' in self.__dict__:
new_state.apps = self.apps.clone()
new_state.is_delayed = self.is_delayed
return new_state
def clear_delayed_apps_cache(self):
if self.is_delayed and 'apps' in self.__dict__:
del self.__dict__['apps']
@cached_property
def apps(self):
return StateApps(self.real_apps, self.models)
@property
def concrete_apps(self):
self.apps = StateApps(self.real_apps, self.models, ignore_swappable=True)
return self.apps
@classmethod
def from_apps(cls, apps):
"""Take an Apps and return a ProjectState matching it."""
app_models = {}
for model in apps.get_models(include_swapped=True):
model_state = ModelState.from_model(model)
app_models[(model_state.app_label, model_state.name_lower)] = model_state
return cls(app_models)
def __eq__(self, other):
return self.models == other.models and set(self.real_apps) == set(other.real_apps)
class AppConfigStub(AppConfig):
"""Stub of an AppConfig. Only provides a label and a dict of models."""
# Not used, but required by AppConfig.__init__
path = ''
def __init__(self, label):
self.label = label
# App-label and app-name are not the same thing, so technically passing
# in the label here is wrong. In practice, migrations don't care about
# the app name, but we need something unique, and the label works fine.
super().__init__(label, None)
def import_models(self):
self.models = self.apps.all_models[self.label]
class StateApps(Apps):
"""
Subclass of the global Apps registry class to better handle dynamic model
additions and removals.
"""
def __init__(self, real_apps, models, ignore_swappable=False):
# Any apps in self.real_apps should have all their models included
# in the render. We don't use the original model instances as there
# are some variables that refer to the Apps object.
# FKs/M2Ms from real apps are also not included as they just
# mess things up with partial states (due to lack of dependencies)
self.real_models = []
for app_label in real_apps:
app = global_apps.get_app_config(app_label)
for model in app.get_models():
self.real_models.append(ModelState.from_model(model, exclude_rels=True))
# Populate the app registry with a stub for each application.
app_labels = {model_state.app_label for model_state in models.values()}
app_configs = [AppConfigStub(label) for label in sorted(real_apps + list(app_labels))]
super().__init__(app_configs)
# The lock gets in the way of copying as implemented in clone(), which
# is called whenever Django duplicates a StateApps before updating it.
self._lock = None
self.render_multiple(list(models.values()) + self.real_models)
# There shouldn't be any operations pending at this point.
from django.core.checks.model_checks import _check_lazy_references
ignore = {make_model_tuple(settings.AUTH_USER_MODEL)} if ignore_swappable else set()
errors = _check_lazy_references(self, ignore=ignore)
if errors:
raise ValueError("\n".join(error.msg for error in errors))
@contextmanager
def bulk_update(self):
# Avoid clearing each model's cache for each change. Instead, clear
# all caches when we're finished updating the model instances.
ready = self.ready
self.ready = False
try:
yield
finally:
self.ready = ready
self.clear_cache()
def render_multiple(self, model_states):
# We keep trying to render the models in a loop, ignoring invalid
# base errors, until the size of the unrendered models doesn't
# decrease by at least one, meaning there's a base dependency loop/
# missing base.
if not model_states:
return
# Prevent that all model caches are expired for each render.
with self.bulk_update():
unrendered_models = model_states
while unrendered_models:
new_unrendered_models = []
for model in unrendered_models:
try:
model.render(self)
except InvalidBasesError:
new_unrendered_models.append(model)
if len(new_unrendered_models) == len(unrendered_models):
raise InvalidBasesError(
"Cannot resolve bases for %r\nThis can happen if you are inheriting models from an "
"app with migrations (e.g. contrib.auth)\n in an app with no migrations; see "
"https://docs.djangoproject.com/en/%s/topics/migrations/#dependencies "
"for more" % (new_unrendered_models, get_docs_version())
)
unrendered_models = new_unrendered_models
def clone(self):
"""Return a clone of this registry."""
clone = StateApps([], {})
clone.all_models = copy.deepcopy(self.all_models)
clone.app_configs = copy.deepcopy(self.app_configs)
# Set the pointer to the correct app registry.
for app_config in clone.app_configs.values():
app_config.apps = clone
# No need to actually clone them, they'll never change
clone.real_models = self.real_models
return clone
def register_model(self, app_label, model):
self.all_models[app_label][model._meta.model_name] = model
if app_label not in self.app_configs:
self.app_configs[app_label] = AppConfigStub(app_label)
self.app_configs[app_label].apps = self
self.app_configs[app_label].models = OrderedDict()
self.app_configs[app_label].models[model._meta.model_name] = model
self.do_pending_operations(model)
self.clear_cache()
def unregister_model(self, app_label, model_name):
try:
del self.all_models[app_label][model_name]
del self.app_configs[app_label].models[model_name]
except KeyError:
pass
class ModelState:
"""
Represent a Django Model. Don't use the actual Model class as it's not
designed to have its options changed - instead, mutate this one and then
render it into a Model as required.
Note that while you are allowed to mutate .fields, you are not allowed
to mutate the Field instances inside there themselves - you must instead
assign new ones, as these are not detached during a clone.
"""
def __init__(self, app_label, name, fields, options=None, bases=None, managers=None):
self.app_label = app_label
self.name = name
self.fields = fields
self.options = options or {}
self.options.setdefault('indexes', [])
self.bases = bases or (models.Model,)
self.managers = managers or []
# Sanity-check that fields is NOT a dict. It must be ordered.
if isinstance(self.fields, dict):
raise ValueError("ModelState.fields cannot be a dict - it must be a list of 2-tuples.")
for name, field in fields:
# Sanity-check that fields are NOT already bound to a model.
if hasattr(field, 'model'):
raise ValueError(
'ModelState.fields cannot be bound to a model - "%s" is.' % name
)
# Sanity-check that relation fields are NOT referring to a model class.
if field.is_relation and hasattr(field.related_model, '_meta'):
raise ValueError(
'ModelState.fields cannot refer to a model class - "%s.to" does. '
'Use a string reference instead.' % name
)
if field.many_to_many and hasattr(field.remote_field.through, '_meta'):
raise ValueError(
'ModelState.fields cannot refer to a model class - "%s.through" does. '
'Use a string reference instead.' % name
)
# Sanity-check that indexes have their name set.
for index in self.options['indexes']:
if not index.name:
raise ValueError(
"Indexes passed to ModelState require a name attribute. "
"%r doesn't have one." % index
)
@cached_property
def name_lower(self):
return self.name.lower()
@classmethod
def from_model(cls, model, exclude_rels=False):
"""Given a model, return a ModelState representing it."""
# Deconstruct the fields
fields = []
for field in model._meta.local_fields:
if getattr(field, "remote_field", None) and exclude_rels:
continue
if isinstance(field, OrderWrt):
continue
name = field.name
try:
fields.append((name, field.clone()))
except TypeError as e:
raise TypeError("Couldn't reconstruct field %s on %s: %s" % (
name,
model._meta.label,
e,
))
if not exclude_rels:
for field in model._meta.local_many_to_many:
name = field.name
try:
fields.append((name, field.clone()))
except TypeError as e:
raise TypeError("Couldn't reconstruct m2m field %s on %s: %s" % (
name,
model._meta.object_name,
e,
))
# Extract the options
options = {}
for name in DEFAULT_NAMES:
# Ignore some special options
if name in ["apps", "app_label"]:
continue
elif name in model._meta.original_attrs:
if name == "unique_together":
ut = model._meta.original_attrs["unique_together"]
options[name] = set(normalize_together(ut))
elif name == "index_together":
it = model._meta.original_attrs["index_together"]
options[name] = set(normalize_together(it))
elif name == "indexes":
indexes = [idx.clone() for idx in model._meta.indexes]
for index in indexes:
if not index.name:
index.set_name_with_model(model)
options['indexes'] = indexes
else:
options[name] = model._meta.original_attrs[name]
# If we're ignoring relationships, remove all field-listing model
# options (that option basically just means "make a stub model")
if exclude_rels:
for key in ["unique_together", "index_together", "order_with_respect_to"]:
if key in options:
del options[key]
# Private fields are ignored, so remove options that refer to them.
elif options.get('order_with_respect_to') in {field.name for field in model._meta.private_fields}:
del options['order_with_respect_to']
def flatten_bases(model):
bases = []
for base in model.__bases__:
if hasattr(base, "_meta") and base._meta.abstract:
bases.extend(flatten_bases(base))
else:
bases.append(base)
return bases
# We can't rely on __mro__ directly because we only want to flatten
# abstract models and not the whole tree. However by recursing on
# __bases__ we may end up with duplicates and ordering issues, we
# therefore discard any duplicates and reorder the bases according
# to their index in the MRO.
flattened_bases = sorted(set(flatten_bases(model)), key=lambda x: model.__mro__.index(x))
# Make our record
bases = tuple(
(
base._meta.label_lower
if hasattr(base, "_meta") else
base
)
for base in flattened_bases
)
# Ensure at least one base inherits from models.Model
if not any((isinstance(base, str) or issubclass(base, models.Model)) for base in bases):
bases = (models.Model,)
managers = []
manager_names = set()
default_manager_shim = None
for manager in model._meta.managers:
if manager.name in manager_names:
# Skip overridden managers.
continue
elif manager.use_in_migrations:
# Copy managers usable in migrations.
new_manager = copy.copy(manager)
new_manager._set_creation_counter()
elif manager is model._base_manager or manager is model._default_manager:
# Shim custom managers used as default and base managers.
new_manager = models.Manager()
new_manager.model = manager.model
new_manager.name = manager.name
if manager is model._default_manager:
default_manager_shim = new_manager
else:
continue
manager_names.add(manager.name)
managers.append((manager.name, new_manager))
# Ignore a shimmed default manager called objects if it's the only one.
if managers == [('objects', default_manager_shim)]:
managers = []
# Construct the new ModelState
return cls(
model._meta.app_label,
model._meta.object_name,
fields,
options,
bases,
managers,
)
def construct_managers(self):
"""Deep-clone the managers using deconstruction."""
# Sort all managers by their creation counter
sorted_managers = sorted(self.managers, key=lambda v: v[1].creation_counter)
for mgr_name, manager in sorted_managers:
as_manager, manager_path, qs_path, args, kwargs = manager.deconstruct()
if as_manager:
qs_class = import_string(qs_path)
yield mgr_name, qs_class.as_manager()
else:
manager_class = import_string(manager_path)
yield mgr_name, manager_class(*args, **kwargs)
def clone(self):
"""Return an exact copy of this ModelState."""
return self.__class__(
app_label=self.app_label,
name=self.name,
fields=list(self.fields),
# Since options are shallow-copied here, operations such as
# AddIndex must replace their option (e.g 'indexes') rather
# than mutating it.
options=dict(self.options),
bases=self.bases,
managers=list(self.managers),
)
def render(self, apps):
"""Create a Model object from our current state into the given apps."""
# First, make a Meta object
meta_contents = {'app_label': self.app_label, 'apps': apps, **self.options}
meta = type("Meta", (), meta_contents)
# Then, work out our bases
try:
bases = tuple(
(apps.get_model(base) if isinstance(base, str) else base)
for base in self.bases
)
except LookupError:
raise InvalidBasesError("Cannot resolve one or more bases from %r" % (self.bases,))
# Turn fields into a dict for the body, add other bits
body = {name: field.clone() for name, field in self.fields}
body['Meta'] = meta
body['__module__'] = "__fake__"
# Restore managers
body.update(self.construct_managers())
# Then, make a Model object (apps.register_model is called in __new__)
return type(self.name, bases, body)
def get_field_by_name(self, name):
for fname, field in self.fields:
if fname == name:
return field
raise ValueError("No field called %s on model %s" % (name, self.name))
def get_index_by_name(self, name):
for index in self.options['indexes']:
if index.name == name:
return index
raise ValueError("No index named %s on model %s" % (name, self.name))
def __repr__(self):
return "<%s: '%s.%s'>" % (self.__class__.__name__, self.app_label, self.name)
def __eq__(self, other):
return (
(self.app_label == other.app_label) and
(self.name == other.name) and
(len(self.fields) == len(other.fields)) and
all((k1 == k2 and (f1.deconstruct()[1:] == f2.deconstruct()[1:]))
for (k1, f1), (k2, f2) in zip(self.fields, other.fields)) and
(self.options == other.options) and
(self.bases == other.bases) and
(self.managers == other.managers)
)
|
39ae11bdf11aea12130aa75cab05d80bae9892714aca5baecbbbed35b49cf8be | from .migration import Migration, swappable_dependency # NOQA
from .operations import * # NOQA
|
bc0f168ebc6d702edac3f1217d2abe7c542b1dfd7461fc321b2b22c8019740bf | import pkgutil
import sys
from importlib import import_module, reload
from django.apps import apps
from django.conf import settings
from django.db.migrations.graph import MigrationGraph
from django.db.migrations.recorder import MigrationRecorder
from .exceptions import (
AmbiguityError, BadMigrationError, InconsistentMigrationHistory,
NodeNotFoundError,
)
MIGRATIONS_MODULE_NAME = 'migrations'
class MigrationLoader:
"""
Load migration files from disk and their status from the database.
Migration files are expected to live in the "migrations" directory of
an app. Their names are entirely unimportant from a code perspective,
but will probably follow the 1234_name.py convention.
On initialization, this class will scan those directories, and open and
read the python files, looking for a class called Migration, which should
inherit from django.db.migrations.Migration. See
django.db.migrations.migration for what that looks like.
Some migrations will be marked as "replacing" another set of migrations.
These are loaded into a separate set of migrations away from the main ones.
If all the migrations they replace are either unapplied or missing from
disk, then they are injected into the main set, replacing the named migrations.
Any dependency pointers to the replaced migrations are re-pointed to the
new migration.
This does mean that this class MUST also talk to the database as well as
to disk, but this is probably fine. We're already not just operating
in memory.
"""
def __init__(self, connection, load=True, ignore_no_migrations=False):
self.connection = connection
self.disk_migrations = None
self.applied_migrations = None
self.ignore_no_migrations = ignore_no_migrations
if load:
self.build_graph()
@classmethod
def migrations_module(cls, app_label):
"""
Return the path to the migrations module for the specified app_label
and a boolean indicating if the module is specified in
settings.MIGRATION_MODULE.
"""
if app_label in settings.MIGRATION_MODULES:
return settings.MIGRATION_MODULES[app_label], True
else:
app_package_name = apps.get_app_config(app_label).name
return '%s.%s' % (app_package_name, MIGRATIONS_MODULE_NAME), False
def load_disk(self):
"""Load the migrations from all INSTALLED_APPS from disk."""
self.disk_migrations = {}
self.unmigrated_apps = set()
self.migrated_apps = set()
for app_config in apps.get_app_configs():
# Get the migrations module directory
module_name, explicit = self.migrations_module(app_config.label)
if module_name is None:
self.unmigrated_apps.add(app_config.label)
continue
was_loaded = module_name in sys.modules
try:
module = import_module(module_name)
except ImportError as e:
# I hate doing this, but I don't want to squash other import errors.
# Might be better to try a directory check directly.
if ((explicit and self.ignore_no_migrations) or (
not explicit and "No module named" in str(e) and MIGRATIONS_MODULE_NAME in str(e))):
self.unmigrated_apps.add(app_config.label)
continue
raise
else:
# Empty directories are namespaces.
# getattr() needed on PY36 and older (replace w/attribute access).
if getattr(module, '__file__', None) is None:
self.unmigrated_apps.add(app_config.label)
continue
# Module is not a package (e.g. migrations.py).
if not hasattr(module, '__path__'):
self.unmigrated_apps.add(app_config.label)
continue
# Force a reload if it's already loaded (tests need this)
if was_loaded:
reload(module)
self.migrated_apps.add(app_config.label)
migration_names = {name for _, name, is_pkg in pkgutil.iter_modules(module.__path__) if not is_pkg}
# Load migrations
for migration_name in migration_names:
migration_path = '%s.%s' % (module_name, migration_name)
try:
migration_module = import_module(migration_path)
except ImportError as e:
if 'bad magic number' in str(e):
raise ImportError(
"Couldn't import %r as it appears to be a stale "
".pyc file." % migration_path
) from e
else:
raise
if not hasattr(migration_module, "Migration"):
raise BadMigrationError(
"Migration %s in app %s has no Migration class" % (migration_name, app_config.label)
)
self.disk_migrations[app_config.label, migration_name] = migration_module.Migration(
migration_name,
app_config.label,
)
def get_migration(self, app_label, name_prefix):
"""Return the named migration or raise NodeNotFoundError."""
return self.graph.nodes[app_label, name_prefix]
def get_migration_by_prefix(self, app_label, name_prefix):
"""
Return the migration(s) which match the given app label and name_prefix.
"""
# Do the search
results = []
for migration_app_label, migration_name in self.disk_migrations:
if migration_app_label == app_label and migration_name.startswith(name_prefix):
results.append((migration_app_label, migration_name))
if len(results) > 1:
raise AmbiguityError(
"There is more than one migration for '%s' with the prefix '%s'" % (app_label, name_prefix)
)
elif not results:
raise KeyError("There no migrations for '%s' with the prefix '%s'" % (app_label, name_prefix))
else:
return self.disk_migrations[results[0]]
def check_key(self, key, current_app):
if (key[1] != "__first__" and key[1] != "__latest__") or key in self.graph:
return key
# Special-case __first__, which means "the first migration" for
# migrated apps, and is ignored for unmigrated apps. It allows
# makemigrations to declare dependencies on apps before they even have
# migrations.
if key[0] == current_app:
# Ignore __first__ references to the same app (#22325)
return
if key[0] in self.unmigrated_apps:
# This app isn't migrated, but something depends on it.
# The models will get auto-added into the state, though
# so we're fine.
return
if key[0] in self.migrated_apps:
try:
if key[1] == "__first__":
return self.graph.root_nodes(key[0])[0]
else: # "__latest__"
return self.graph.leaf_nodes(key[0])[0]
except IndexError:
if self.ignore_no_migrations:
return None
else:
raise ValueError("Dependency on app with no migrations: %s" % key[0])
raise ValueError("Dependency on unknown app: %s" % key[0])
def add_internal_dependencies(self, key, migration):
"""
Internal dependencies need to be added first to ensure `__first__`
dependencies find the correct root node.
"""
for parent in migration.dependencies:
# Ignore __first__ references to the same app.
if parent[0] == key[0] and parent[1] != '__first__':
self.graph.add_dependency(migration, key, parent, skip_validation=True)
def add_external_dependencies(self, key, migration):
for parent in migration.dependencies:
# Skip internal dependencies
if key[0] == parent[0]:
continue
parent = self.check_key(parent, key[0])
if parent is not None:
self.graph.add_dependency(migration, key, parent, skip_validation=True)
for child in migration.run_before:
child = self.check_key(child, key[0])
if child is not None:
self.graph.add_dependency(migration, child, key, skip_validation=True)
def build_graph(self):
"""
Build a migration dependency graph using both the disk and database.
You'll need to rebuild the graph if you apply migrations. This isn't
usually a problem as generally migration stuff runs in a one-shot process.
"""
# Load disk data
self.load_disk()
# Load database data
if self.connection is None:
self.applied_migrations = set()
else:
recorder = MigrationRecorder(self.connection)
self.applied_migrations = recorder.applied_migrations()
# To start, populate the migration graph with nodes for ALL migrations
# and their dependencies. Also make note of replacing migrations at this step.
self.graph = MigrationGraph()
self.replacements = {}
for key, migration in self.disk_migrations.items():
self.graph.add_node(key, migration)
# Internal (aka same-app) dependencies.
self.add_internal_dependencies(key, migration)
# Replacing migrations.
if migration.replaces:
self.replacements[key] = migration
# Add external dependencies now that the internal ones have been resolved.
for key, migration in self.disk_migrations.items():
self.add_external_dependencies(key, migration)
# Carry out replacements where possible.
for key, migration in self.replacements.items():
# Get applied status of each of this migration's replacement targets.
applied_statuses = [(target in self.applied_migrations) for target in migration.replaces]
# Ensure the replacing migration is only marked as applied if all of
# its replacement targets are.
if all(applied_statuses):
self.applied_migrations.add(key)
else:
self.applied_migrations.discard(key)
# A replacing migration can be used if either all or none of its
# replacement targets have been applied.
if all(applied_statuses) or (not any(applied_statuses)):
self.graph.remove_replaced_nodes(key, migration.replaces)
else:
# This replacing migration cannot be used because it is partially applied.
# Remove it from the graph and remap dependencies to it (#25945).
self.graph.remove_replacement_node(key, migration.replaces)
# Ensure the graph is consistent.
try:
self.graph.validate_consistency()
except NodeNotFoundError as exc:
# Check if the missing node could have been replaced by any squash
# migration but wasn't because the squash migration was partially
# applied before. In that case raise a more understandable exception
# (#23556).
# Get reverse replacements.
reverse_replacements = {}
for key, migration in self.replacements.items():
for replaced in migration.replaces:
reverse_replacements.setdefault(replaced, set()).add(key)
# Try to reraise exception with more detail.
if exc.node in reverse_replacements:
candidates = reverse_replacements.get(exc.node, set())
is_replaced = any(candidate in self.graph.nodes for candidate in candidates)
if not is_replaced:
tries = ', '.join('%s.%s' % c for c in candidates)
raise NodeNotFoundError(
"Migration {0} depends on nonexistent node ('{1}', '{2}'). "
"Django tried to replace migration {1}.{2} with any of [{3}] "
"but wasn't able to because some of the replaced migrations "
"are already applied.".format(
exc.origin, exc.node[0], exc.node[1], tries
),
exc.node
) from exc
raise exc
def check_consistent_history(self, connection):
"""
Raise InconsistentMigrationHistory if any applied migrations have
unapplied dependencies.
"""
recorder = MigrationRecorder(connection)
applied = recorder.applied_migrations()
for migration in applied:
# If the migration is unknown, skip it.
if migration not in self.graph.nodes:
continue
for parent in self.graph.node_map[migration].parents:
if parent not in applied:
# Skip unapplied squashed migrations that have all of their
# `replaces` applied.
if parent in self.replacements:
if all(m in applied for m in self.replacements[parent].replaces):
continue
raise InconsistentMigrationHistory(
"Migration {}.{} is applied before its dependency "
"{}.{} on database '{}'.".format(
migration[0], migration[1], parent[0], parent[1],
connection.alias,
)
)
def detect_conflicts(self):
"""
Look through the loaded graph and detect any conflicts - apps
with more than one leaf migration. Return a dict of the app labels
that conflict with the migration names that conflict.
"""
seen_apps = {}
conflicting_apps = set()
for app_label, migration_name in self.graph.leaf_nodes():
if app_label in seen_apps:
conflicting_apps.add(app_label)
seen_apps.setdefault(app_label, set()).add(migration_name)
return {app_label: seen_apps[app_label] for app_label in conflicting_apps}
def project_state(self, nodes=None, at_end=True):
"""
Return a ProjectState object representing the most recent state
that the loaded migrations represent.
See graph.make_state() for the meaning of "nodes" and "at_end".
"""
return self.graph.make_state(nodes=nodes, at_end=at_end, real_apps=list(self.unmigrated_apps))
|
71f6baabd59546c4e6c08b9c363abc5b631bbd203e08d0a17a7637bc589ee318 | from django.db.utils import DatabaseError
class AmbiguityError(Exception):
"""More than one migration matches a name prefix."""
pass
class BadMigrationError(Exception):
"""There's a bad migration (unreadable/bad format/etc.)."""
pass
class CircularDependencyError(Exception):
"""There's an impossible-to-resolve circular dependency."""
pass
class InconsistentMigrationHistory(Exception):
"""An applied migration has some of its dependencies not applied."""
pass
class InvalidBasesError(ValueError):
"""A model's base classes can't be resolved."""
pass
class IrreversibleError(RuntimeError):
"""An irreversible migration is about to be reversed."""
pass
class NodeNotFoundError(LookupError):
"""An attempt on a node is made that is not available in the graph."""
def __init__(self, message, node, origin=None):
self.message = message
self.origin = origin
self.node = node
def __str__(self):
return self.message
def __repr__(self):
return "NodeNotFoundError(%r)" % (self.node,)
class MigrationSchemaMissing(DatabaseError):
pass
class InvalidMigrationPlan(ValueError):
pass
|
6c08a35516d0b29fa2c4ce835905757cda0a4830b9b9dc269dd016384db958de | import os
import re
from importlib import import_module
from django import get_version
from django.apps import apps
from django.db import migrations
from django.db.migrations.loader import MigrationLoader
from django.db.migrations.serializer import serializer_factory
from django.utils.inspect import get_func_args
from django.utils.module_loading import module_dir
from django.utils.timezone import now
class SettingsReference(str):
"""
Special subclass of string which actually references a current settings
value. It's treated as the value in memory, but serializes out to a
settings.NAME attribute reference.
"""
def __new__(self, value, setting_name):
return str.__new__(self, value)
def __init__(self, value, setting_name):
self.setting_name = setting_name
class OperationWriter:
def __init__(self, operation, indentation=2):
self.operation = operation
self.buff = []
self.indentation = indentation
def serialize(self):
def _write(_arg_name, _arg_value):
if (_arg_name in self.operation.serialization_expand_args and
isinstance(_arg_value, (list, tuple, dict))):
if isinstance(_arg_value, dict):
self.feed('%s={' % _arg_name)
self.indent()
for key, value in _arg_value.items():
key_string, key_imports = MigrationWriter.serialize(key)
arg_string, arg_imports = MigrationWriter.serialize(value)
args = arg_string.splitlines()
if len(args) > 1:
self.feed('%s: %s' % (key_string, args[0]))
for arg in args[1:-1]:
self.feed(arg)
self.feed('%s,' % args[-1])
else:
self.feed('%s: %s,' % (key_string, arg_string))
imports.update(key_imports)
imports.update(arg_imports)
self.unindent()
self.feed('},')
else:
self.feed('%s=[' % _arg_name)
self.indent()
for item in _arg_value:
arg_string, arg_imports = MigrationWriter.serialize(item)
args = arg_string.splitlines()
if len(args) > 1:
for arg in args[:-1]:
self.feed(arg)
self.feed('%s,' % args[-1])
else:
self.feed('%s,' % arg_string)
imports.update(arg_imports)
self.unindent()
self.feed('],')
else:
arg_string, arg_imports = MigrationWriter.serialize(_arg_value)
args = arg_string.splitlines()
if len(args) > 1:
self.feed('%s=%s' % (_arg_name, args[0]))
for arg in args[1:-1]:
self.feed(arg)
self.feed('%s,' % args[-1])
else:
self.feed('%s=%s,' % (_arg_name, arg_string))
imports.update(arg_imports)
imports = set()
name, args, kwargs = self.operation.deconstruct()
operation_args = get_func_args(self.operation.__init__)
# See if this operation is in django.db.migrations. If it is,
# We can just use the fact we already have that imported,
# otherwise, we need to add an import for the operation class.
if getattr(migrations, name, None) == self.operation.__class__:
self.feed('migrations.%s(' % name)
else:
imports.add('import %s' % (self.operation.__class__.__module__))
self.feed('%s.%s(' % (self.operation.__class__.__module__, name))
self.indent()
for i, arg in enumerate(args):
arg_value = arg
arg_name = operation_args[i]
_write(arg_name, arg_value)
i = len(args)
# Only iterate over remaining arguments
for arg_name in operation_args[i:]:
if arg_name in kwargs: # Don't sort to maintain signature order
arg_value = kwargs[arg_name]
_write(arg_name, arg_value)
self.unindent()
self.feed('),')
return self.render(), imports
def indent(self):
self.indentation += 1
def unindent(self):
self.indentation -= 1
def feed(self, line):
self.buff.append(' ' * (self.indentation * 4) + line)
def render(self):
return '\n'.join(self.buff)
class MigrationWriter:
"""
Take a Migration instance and is able to produce the contents
of the migration file from it.
"""
def __init__(self, migration):
self.migration = migration
self.needs_manual_porting = False
def as_string(self):
"""Return a string of the file contents."""
items = {
"replaces_str": "",
"initial_str": "",
}
imports = set()
# Deconstruct operations
operations = []
for operation in self.migration.operations:
operation_string, operation_imports = OperationWriter(operation).serialize()
imports.update(operation_imports)
operations.append(operation_string)
items["operations"] = "\n".join(operations) + "\n" if operations else ""
# Format dependencies and write out swappable dependencies right
dependencies = []
for dependency in self.migration.dependencies:
if dependency[0] == "__setting__":
dependencies.append(" migrations.swappable_dependency(settings.%s)," % dependency[1])
imports.add("from django.conf import settings")
else:
dependencies.append(" %s," % self.serialize(dependency)[0])
items["dependencies"] = "\n".join(dependencies) + "\n" if dependencies else ""
# Format imports nicely, swapping imports of functions from migration files
# for comments
migration_imports = set()
for line in list(imports):
if re.match(r"^import (.*)\.\d+[^\s]*$", line):
migration_imports.add(line.split("import")[1].strip())
imports.remove(line)
self.needs_manual_porting = True
# django.db.migrations is always used, but models import may not be.
# If models import exists, merge it with migrations import.
if "from django.db import models" in imports:
imports.discard("from django.db import models")
imports.add("from django.db import migrations, models")
else:
imports.add("from django.db import migrations")
# Sort imports by the package / module to be imported (the part after
# "from" in "from ... import ..." or after "import" in "import ...").
sorted_imports = sorted(imports, key=lambda i: i.split()[1])
items["imports"] = "\n".join(sorted_imports) + "\n" if imports else ""
if migration_imports:
items["imports"] += (
"\n\n# Functions from the following migrations need manual "
"copying.\n# Move them and any dependencies into this file, "
"then update the\n# RunPython operations to refer to the local "
"versions:\n# %s"
) % "\n# ".join(sorted(migration_imports))
# If there's a replaces, make a string for it
if self.migration.replaces:
items['replaces_str'] = "\n replaces = %s\n" % self.serialize(self.migration.replaces)[0]
# Hinting that goes into comment
items.update(
version=get_version(),
timestamp=now().strftime("%Y-%m-%d %H:%M"),
)
if self.migration.initial:
items['initial_str'] = "\n initial = True\n"
return MIGRATION_TEMPLATE % items
@property
def basedir(self):
migrations_package_name, _ = MigrationLoader.migrations_module(self.migration.app_label)
if migrations_package_name is None:
raise ValueError(
"Django can't create migrations for app '%s' because "
"migrations have been disabled via the MIGRATION_MODULES "
"setting." % self.migration.app_label
)
# See if we can import the migrations module directly
try:
migrations_module = import_module(migrations_package_name)
except ImportError:
pass
else:
try:
return module_dir(migrations_module)
except ValueError:
pass
# Alright, see if it's a direct submodule of the app
app_config = apps.get_app_config(self.migration.app_label)
maybe_app_name, _, migrations_package_basename = migrations_package_name.rpartition(".")
if app_config.name == maybe_app_name:
return os.path.join(app_config.path, migrations_package_basename)
# In case of using MIGRATION_MODULES setting and the custom package
# doesn't exist, create one, starting from an existing package
existing_dirs, missing_dirs = migrations_package_name.split("."), []
while existing_dirs:
missing_dirs.insert(0, existing_dirs.pop(-1))
try:
base_module = import_module(".".join(existing_dirs))
except (ImportError, ValueError):
continue
else:
try:
base_dir = module_dir(base_module)
except ValueError:
continue
else:
break
else:
raise ValueError(
"Could not locate an appropriate location to create "
"migrations package %s. Make sure the toplevel "
"package exists and can be imported." %
migrations_package_name)
final_dir = os.path.join(base_dir, *missing_dirs)
if not os.path.isdir(final_dir):
os.makedirs(final_dir)
for missing_dir in missing_dirs:
base_dir = os.path.join(base_dir, missing_dir)
with open(os.path.join(base_dir, "__init__.py"), "w"):
pass
return final_dir
@property
def filename(self):
return "%s.py" % self.migration.name
@property
def path(self):
return os.path.join(self.basedir, self.filename)
@classmethod
def serialize(cls, value):
return serializer_factory(value).serialize()
MIGRATION_TEMPLATE = """\
# Generated by Django %(version)s on %(timestamp)s
%(imports)s
class Migration(migrations.Migration):
%(replaces_str)s%(initial_str)s
dependencies = [
%(dependencies)s\
]
operations = [
%(operations)s\
]
"""
|
ecbe9f72fd272af3071917d12d2fcaf17182b31b5d3df03ac10c91990df4f960 | import importlib
import os
import sys
from django.apps import apps
from django.db.models.fields import NOT_PROVIDED
from django.utils import datetime_safe, timezone
from .loader import MigrationLoader
class MigrationQuestioner:
"""
Give the autodetector responses to questions it might have.
This base class has a built-in noninteractive mode, but the
interactive subclass is what the command-line arguments will use.
"""
def __init__(self, defaults=None, specified_apps=None, dry_run=None):
self.defaults = defaults or {}
self.specified_apps = specified_apps or set()
self.dry_run = dry_run
def ask_initial(self, app_label):
"""Should we create an initial migration for the app?"""
# If it was specified on the command line, definitely true
if app_label in self.specified_apps:
return True
# Otherwise, we look to see if it has a migrations module
# without any Python files in it, apart from __init__.py.
# Apps from the new app template will have these; the python
# file check will ensure we skip South ones.
try:
app_config = apps.get_app_config(app_label)
except LookupError: # It's a fake app.
return self.defaults.get("ask_initial", False)
migrations_import_path, _ = MigrationLoader.migrations_module(app_config.label)
if migrations_import_path is None:
# It's an application with migrations disabled.
return self.defaults.get("ask_initial", False)
try:
migrations_module = importlib.import_module(migrations_import_path)
except ImportError:
return self.defaults.get("ask_initial", False)
else:
# getattr() needed on PY36 and older (replace with attribute access).
if getattr(migrations_module, "__file__", None):
filenames = os.listdir(os.path.dirname(migrations_module.__file__))
elif hasattr(migrations_module, "__path__"):
if len(migrations_module.__path__) > 1:
return False
filenames = os.listdir(list(migrations_module.__path__)[0])
return not any(x.endswith(".py") for x in filenames if x != "__init__.py")
def ask_not_null_addition(self, field_name, model_name):
"""Adding a NOT NULL field to a model."""
# None means quit
return None
def ask_not_null_alteration(self, field_name, model_name):
"""Changing a NULL field to NOT NULL."""
# None means quit
return None
def ask_rename(self, model_name, old_name, new_name, field_instance):
"""Was this field really renamed?"""
return self.defaults.get("ask_rename", False)
def ask_rename_model(self, old_model_state, new_model_state):
"""Was this model really renamed?"""
return self.defaults.get("ask_rename_model", False)
def ask_merge(self, app_label):
"""Do you really want to merge these migrations?"""
return self.defaults.get("ask_merge", False)
def ask_auto_now_add_addition(self, field_name, model_name):
"""Adding an auto_now_add field to a model."""
# None means quit
return None
class InteractiveMigrationQuestioner(MigrationQuestioner):
def _boolean_input(self, question, default=None):
result = input("%s " % question)
if not result and default is not None:
return default
while not result or result[0].lower() not in "yn":
result = input("Please answer yes or no: ")
return result[0].lower() == "y"
def _choice_input(self, question, choices):
print(question)
for i, choice in enumerate(choices):
print(" %s) %s" % (i + 1, choice))
result = input("Select an option: ")
while True:
try:
value = int(result)
except ValueError:
pass
else:
if 0 < value <= len(choices):
return value
result = input("Please select a valid option: ")
def _ask_default(self, default=''):
"""
Prompt for a default value.
The ``default`` argument allows providing a custom default value (as a
string) which will be shown to the user and used as the return value
if the user doesn't provide any other input.
"""
print("Please enter the default value now, as valid Python")
if default:
print(
"You can accept the default '{}' by pressing 'Enter' or you "
"can provide another value.".format(default)
)
print("The datetime and django.utils.timezone modules are available, so you can do e.g. timezone.now")
print("Type 'exit' to exit this prompt")
while True:
if default:
prompt = "[default: {}] >>> ".format(default)
else:
prompt = ">>> "
code = input(prompt)
if not code and default:
code = default
if not code:
print("Please enter some code, or 'exit' (with no quotes) to exit.")
elif code == "exit":
sys.exit(1)
else:
try:
return eval(code, {}, {"datetime": datetime_safe, "timezone": timezone})
except (SyntaxError, NameError) as e:
print("Invalid input: %s" % e)
def ask_not_null_addition(self, field_name, model_name):
"""Adding a NOT NULL field to a model."""
if not self.dry_run:
choice = self._choice_input(
"You are trying to add a non-nullable field '%s' to %s without a default; "
"we can't do that (the database needs something to populate existing rows).\n"
"Please select a fix:" % (field_name, model_name),
[
("Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"),
"Quit, and let me add a default in models.py",
]
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default()
return None
def ask_not_null_alteration(self, field_name, model_name):
"""Changing a NULL field to NOT NULL."""
if not self.dry_run:
choice = self._choice_input(
"You are trying to change the nullable field '%s' on %s to non-nullable "
"without a default; we can't do that (the database needs something to "
"populate existing rows).\n"
"Please select a fix:" % (field_name, model_name),
[
("Provide a one-off default now (will be set on all existing "
"rows with a null value for this column)"),
("Ignore for now, and let me handle existing rows with NULL myself "
"(e.g. because you added a RunPython or RunSQL operation to handle "
"NULL values in a previous data migration)"),
"Quit, and let me add a default in models.py",
]
)
if choice == 2:
return NOT_PROVIDED
elif choice == 3:
sys.exit(3)
else:
return self._ask_default()
return None
def ask_rename(self, model_name, old_name, new_name, field_instance):
"""Was this field really renamed?"""
msg = "Did you rename %s.%s to %s.%s (a %s)? [y/N]"
return self._boolean_input(msg % (model_name, old_name, model_name, new_name,
field_instance.__class__.__name__), False)
def ask_rename_model(self, old_model_state, new_model_state):
"""Was this model really renamed?"""
msg = "Did you rename the %s.%s model to %s? [y/N]"
return self._boolean_input(msg % (old_model_state.app_label, old_model_state.name,
new_model_state.name), False)
def ask_merge(self, app_label):
return self._boolean_input(
"\nMerging will only work if the operations printed above do not conflict\n" +
"with each other (working on different fields or models)\n" +
"Do you want to merge these migration branches? [y/N]",
False,
)
def ask_auto_now_add_addition(self, field_name, model_name):
"""Adding an auto_now_add field to a model."""
if not self.dry_run:
choice = self._choice_input(
"You are trying to add the field '{}' with 'auto_now_add=True' "
"to {} without a default; the database needs something to "
"populate existing rows.\n".format(field_name, model_name),
[
"Provide a one-off default now (will be set on all "
"existing rows)",
"Quit, and let me add a default in models.py",
]
)
if choice == 2:
sys.exit(3)
else:
return self._ask_default(default='timezone.now')
return None
class NonInteractiveMigrationQuestioner(MigrationQuestioner):
def ask_not_null_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
sys.exit(3)
def ask_not_null_alteration(self, field_name, model_name):
# We can't ask the user, so set as not provided.
return NOT_PROVIDED
def ask_auto_now_add_addition(self, field_name, model_name):
# We can't ask the user, so act like the user aborted.
sys.exit(3)
|
b3bb1756579ae81880800156c68ad51d34a86241171658c3f00c8a452c5c4168 | import warnings
from functools import total_ordering
from django.db.migrations.state import ProjectState
from django.utils.datastructures import OrderedSet
from .exceptions import CircularDependencyError, NodeNotFoundError
RECURSION_DEPTH_WARNING = (
"Maximum recursion depth exceeded while generating migration graph, "
"falling back to iterative approach. If you're experiencing performance issues, "
"consider squashing migrations as described at "
"https://docs.djangoproject.com/en/dev/topics/migrations/#squashing-migrations."
)
@total_ordering
class Node:
"""
A single node in the migration graph. Contains direct links to adjacent
nodes in either direction.
"""
def __init__(self, key):
self.key = key
self.children = set()
self.parents = set()
def __eq__(self, other):
return self.key == other
def __lt__(self, other):
return self.key < other
def __hash__(self):
return hash(self.key)
def __getitem__(self, item):
return self.key[item]
def __str__(self):
return str(self.key)
def __repr__(self):
return '<%s: (%r, %r)>' % (self.__class__.__name__, self.key[0], self.key[1])
def add_child(self, child):
self.children.add(child)
def add_parent(self, parent):
self.parents.add(parent)
# Use manual caching, @cached_property effectively doubles the
# recursion depth for each recursion.
def ancestors(self):
# Use self.key instead of self to speed up the frequent hashing
# when constructing an OrderedSet.
if '_ancestors' not in self.__dict__:
ancestors = []
for parent in sorted(self.parents, reverse=True):
ancestors += parent.ancestors()
ancestors.append(self.key)
self.__dict__['_ancestors'] = list(OrderedSet(ancestors))
return self.__dict__['_ancestors']
# Use manual caching, @cached_property effectively doubles the
# recursion depth for each recursion.
def descendants(self):
# Use self.key instead of self to speed up the frequent hashing
# when constructing an OrderedSet.
if '_descendants' not in self.__dict__:
descendants = []
for child in sorted(self.children, reverse=True):
descendants += child.descendants()
descendants.append(self.key)
self.__dict__['_descendants'] = list(OrderedSet(descendants))
return self.__dict__['_descendants']
class DummyNode(Node):
def __init__(self, key, origin, error_message):
super().__init__(key)
self.origin = origin
self.error_message = error_message
def promote(self):
"""
Transition dummy to a normal node and clean off excess attribs.
Creating a Node object from scratch would be too much of a
hassle as many dependendies would need to be remapped.
"""
del self.origin
del self.error_message
self.__class__ = Node
def raise_error(self):
raise NodeNotFoundError(self.error_message, self.key, origin=self.origin)
class MigrationGraph:
"""
Represent the digraph of all migrations in a project.
Each migration is a node, and each dependency is an edge. There are
no implicit dependencies between numbered migrations - the numbering is
merely a convention to aid file listing. Every new numbered migration
has a declared dependency to the previous number, meaning that VCS
branch merges can be detected and resolved.
Migrations files can be marked as replacing another set of migrations -
this is to support the "squash" feature. The graph handler isn't responsible
for these; instead, the code to load them in here should examine the
migration files and if the replaced migrations are all either unapplied
or not present, it should ignore the replaced ones, load in just the
replacing migration, and repoint any dependencies that pointed to the
replaced migrations to point to the replacing one.
A node should be a tuple: (app_path, migration_name). The tree special-cases
things within an app - namely, root nodes and leaf nodes ignore dependencies
to other apps.
"""
def __init__(self):
self.node_map = {}
self.nodes = {}
self.cached = False
def add_node(self, key, migration):
# If the key already exists, then it must be a dummy node.
dummy_node = self.node_map.get(key)
if dummy_node:
# Promote DummyNode to Node.
dummy_node.promote()
else:
node = Node(key)
self.node_map[key] = node
self.nodes[key] = migration
self.clear_cache()
def add_dummy_node(self, key, origin, error_message):
node = DummyNode(key, origin, error_message)
self.node_map[key] = node
self.nodes[key] = None
def add_dependency(self, migration, child, parent, skip_validation=False):
"""
This may create dummy nodes if they don't yet exist. If
`skip_validation=True`, validate_consistency() should be called
afterwards.
"""
if child not in self.nodes:
error_message = (
"Migration %s dependencies reference nonexistent"
" child node %r" % (migration, child)
)
self.add_dummy_node(child, migration, error_message)
if parent not in self.nodes:
error_message = (
"Migration %s dependencies reference nonexistent"
" parent node %r" % (migration, parent)
)
self.add_dummy_node(parent, migration, error_message)
self.node_map[child].add_parent(self.node_map[parent])
self.node_map[parent].add_child(self.node_map[child])
if not skip_validation:
self.validate_consistency()
self.clear_cache()
def remove_replaced_nodes(self, replacement, replaced):
"""
Remove each of the `replaced` nodes (when they exist). Any
dependencies that were referencing them are changed to reference the
`replacement` node instead.
"""
# Cast list of replaced keys to set to speed up lookup later.
replaced = set(replaced)
try:
replacement_node = self.node_map[replacement]
except KeyError as err:
raise NodeNotFoundError(
"Unable to find replacement node %r. It was either never added"
" to the migration graph, or has been removed." % (replacement,),
replacement
) from err
for replaced_key in replaced:
self.nodes.pop(replaced_key, None)
replaced_node = self.node_map.pop(replaced_key, None)
if replaced_node:
for child in replaced_node.children:
child.parents.remove(replaced_node)
# We don't want to create dependencies between the replaced
# node and the replacement node as this would lead to
# self-referencing on the replacement node at a later iteration.
if child.key not in replaced:
replacement_node.add_child(child)
child.add_parent(replacement_node)
for parent in replaced_node.parents:
parent.children.remove(replaced_node)
# Again, to avoid self-referencing.
if parent.key not in replaced:
replacement_node.add_parent(parent)
parent.add_child(replacement_node)
self.clear_cache()
def remove_replacement_node(self, replacement, replaced):
"""
The inverse operation to `remove_replaced_nodes`. Almost. Remove the
replacement node `replacement` and remap its child nodes to `replaced`
- the list of nodes it would have replaced. Don't remap its parent
nodes as they are expected to be correct already.
"""
self.nodes.pop(replacement, None)
try:
replacement_node = self.node_map.pop(replacement)
except KeyError as err:
raise NodeNotFoundError(
"Unable to remove replacement node %r. It was either never added"
" to the migration graph, or has been removed already." % (replacement,),
replacement
) from err
replaced_nodes = set()
replaced_nodes_parents = set()
for key in replaced:
replaced_node = self.node_map.get(key)
if replaced_node:
replaced_nodes.add(replaced_node)
replaced_nodes_parents |= replaced_node.parents
# We're only interested in the latest replaced node, so filter out
# replaced nodes that are parents of other replaced nodes.
replaced_nodes -= replaced_nodes_parents
for child in replacement_node.children:
child.parents.remove(replacement_node)
for replaced_node in replaced_nodes:
replaced_node.add_child(child)
child.add_parent(replaced_node)
for parent in replacement_node.parents:
parent.children.remove(replacement_node)
# NOTE: There is no need to remap parent dependencies as we can
# assume the replaced nodes already have the correct ancestry.
self.clear_cache()
def validate_consistency(self):
"""Ensure there are no dummy nodes remaining in the graph."""
[n.raise_error() for n in self.node_map.values() if isinstance(n, DummyNode)]
def clear_cache(self):
if self.cached:
for node in self.nodes:
self.node_map[node].__dict__.pop('_ancestors', None)
self.node_map[node].__dict__.pop('_descendants', None)
self.cached = False
def forwards_plan(self, target):
"""
Given a node, return a list of which previous nodes (dependencies) must
be applied, ending with the node itself. This is the list you would
follow if applying the migrations to a database.
"""
if target not in self.nodes:
raise NodeNotFoundError("Node %r not a valid node" % (target,), target)
# Use parent.key instead of parent to speed up the frequent hashing in ensure_not_cyclic
self.ensure_not_cyclic(target, lambda x: (parent.key for parent in self.node_map[x].parents))
self.cached = True
node = self.node_map[target]
try:
return node.ancestors()
except RuntimeError:
# fallback to iterative dfs
warnings.warn(RECURSION_DEPTH_WARNING, RuntimeWarning)
return self.iterative_dfs(node)
def backwards_plan(self, target):
"""
Given a node, return a list of which dependent nodes (dependencies)
must be unapplied, ending with the node itself. This is the list you
would follow if removing the migrations from a database.
"""
if target not in self.nodes:
raise NodeNotFoundError("Node %r not a valid node" % (target,), target)
# Use child.key instead of child to speed up the frequent hashing in ensure_not_cyclic
self.ensure_not_cyclic(target, lambda x: (child.key for child in self.node_map[x].children))
self.cached = True
node = self.node_map[target]
try:
return node.descendants()
except RuntimeError:
# fallback to iterative dfs
warnings.warn(RECURSION_DEPTH_WARNING, RuntimeWarning)
return self.iterative_dfs(node, forwards=False)
def iterative_dfs(self, start, forwards=True):
"""Iterative depth-first search for finding dependencies."""
visited = []
stack = [start]
while stack:
node = stack.pop()
visited.append(node)
stack += sorted(node.parents if forwards else node.children)
return list(OrderedSet(reversed(visited)))
def root_nodes(self, app=None):
"""
Return all root nodes - that is, nodes with no dependencies inside
their app. These are the starting point for an app.
"""
roots = set()
for node in self.nodes:
if all(key[0] != node[0] for key in self.node_map[node].parents) and (not app or app == node[0]):
roots.add(node)
return sorted(roots)
def leaf_nodes(self, app=None):
"""
Return all leaf nodes - that is, nodes with no dependents in their app.
These are the "most current" version of an app's schema.
Having more than one per app is technically an error, but one that
gets handled further up, in the interactive command - it's usually the
result of a VCS merge and needs some user input.
"""
leaves = set()
for node in self.nodes:
if all(key[0] != node[0] for key in self.node_map[node].children) and (not app or app == node[0]):
leaves.add(node)
return sorted(leaves)
def ensure_not_cyclic(self, start, get_children):
# Algo from GvR:
# http://neopythonic.blogspot.co.uk/2009/01/detecting-cycles-in-directed-graph.html
todo = set(self.nodes)
while todo:
node = todo.pop()
stack = [node]
while stack:
top = stack[-1]
for node in get_children(top):
if node in stack:
cycle = stack[stack.index(node):]
raise CircularDependencyError(", ".join("%s.%s" % n for n in cycle))
if node in todo:
stack.append(node)
todo.remove(node)
break
else:
node = stack.pop()
def __str__(self):
return 'Graph: %s nodes, %s edges' % self._nodes_and_edges()
def __repr__(self):
nodes, edges = self._nodes_and_edges()
return '<%s: nodes=%s, edges=%s>' % (self.__class__.__name__, nodes, edges)
def _nodes_and_edges(self):
return len(self.nodes), sum(len(node.parents) for node in self.node_map.values())
def _generate_plan(self, nodes, at_end):
plan = []
for node in nodes:
for migration in self.forwards_plan(node):
if migration not in plan and (at_end or migration not in nodes):
plan.append(migration)
return plan
def make_state(self, nodes=None, at_end=True, real_apps=None):
"""
Given a migration node or nodes, return a complete ProjectState for it.
If at_end is False, return the state before the migration has run.
If nodes is not provided, return the overall most current project state.
"""
if nodes is None:
nodes = list(self.leaf_nodes())
if not nodes:
return ProjectState()
if not isinstance(nodes[0], tuple):
nodes = [nodes]
plan = self._generate_plan(nodes, at_end)
project_state = ProjectState(real_apps=real_apps)
for node in plan:
project_state = self.nodes[node].mutate_state(project_state, preserve=False)
return project_state
def __contains__(self, node):
return node in self.nodes
|
6d88c943648cbe824b4f8c005d301f4e0a0c491757110c145f7613337de4178f | import functools
import re
from itertools import chain
from django.conf import settings
from django.db import models
from django.db.migrations import operations
from django.db.migrations.migration import Migration
from django.db.migrations.operations.models import AlterModelOptions
from django.db.migrations.optimizer import MigrationOptimizer
from django.db.migrations.questioner import MigrationQuestioner
from django.db.migrations.utils import (
COMPILED_REGEX_TYPE, RegexObject, get_migration_name_timestamp,
)
from .topological_sort import stable_topological_sort
class MigrationAutodetector:
"""
Take a pair of ProjectStates and compare them to see what the first would
need doing to make it match the second (the second usually being the
project's current state).
Note that this naturally operates on entire projects at a time,
as it's likely that changes interact (for example, you can't
add a ForeignKey without having a migration to add the table it
depends on first). A user interface may offer single-app usage
if it wishes, with the caveat that it may not always be possible.
"""
def __init__(self, from_state, to_state, questioner=None):
self.from_state = from_state
self.to_state = to_state
self.questioner = questioner or MigrationQuestioner()
self.existing_apps = {app for app, model in from_state.models}
def changes(self, graph, trim_to_apps=None, convert_apps=None, migration_name=None):
"""
Main entry point to produce a list of applicable changes.
Take a graph to base names on and an optional set of apps
to try and restrict to (restriction is not guaranteed)
"""
changes = self._detect_changes(convert_apps, graph)
changes = self.arrange_for_graph(changes, graph, migration_name)
if trim_to_apps:
changes = self._trim_to_apps(changes, trim_to_apps)
return changes
def deep_deconstruct(self, obj):
"""
Recursive deconstruction for a field and its arguments.
Used for full comparison for rename/alter; sometimes a single-level
deconstruction will not compare correctly.
"""
if isinstance(obj, list):
return [self.deep_deconstruct(value) for value in obj]
elif isinstance(obj, tuple):
return tuple(self.deep_deconstruct(value) for value in obj)
elif isinstance(obj, dict):
return {
key: self.deep_deconstruct(value)
for key, value in obj.items()
}
elif isinstance(obj, functools.partial):
return (obj.func, self.deep_deconstruct(obj.args), self.deep_deconstruct(obj.keywords))
elif isinstance(obj, COMPILED_REGEX_TYPE):
return RegexObject(obj)
elif isinstance(obj, type):
# If this is a type that implements 'deconstruct' as an instance method,
# avoid treating this as being deconstructible itself - see #22951
return obj
elif hasattr(obj, 'deconstruct'):
deconstructed = obj.deconstruct()
if isinstance(obj, models.Field):
# we have a field which also returns a name
deconstructed = deconstructed[1:]
path, args, kwargs = deconstructed
return (
path,
[self.deep_deconstruct(value) for value in args],
{
key: self.deep_deconstruct(value)
for key, value in kwargs.items()
},
)
else:
return obj
def only_relation_agnostic_fields(self, fields):
"""
Return a definition of the fields that ignores field names and
what related fields actually relate to. Used for detecting renames (as,
of course, the related fields change during renames).
"""
fields_def = []
for name, field in sorted(fields):
deconstruction = self.deep_deconstruct(field)
if field.remote_field and field.remote_field.model:
del deconstruction[2]['to']
fields_def.append(deconstruction)
return fields_def
def _detect_changes(self, convert_apps=None, graph=None):
"""
Return a dict of migration plans which will achieve the
change from from_state to to_state. The dict has app labels
as keys and a list of migrations as values.
The resulting migrations aren't specially named, but the names
do matter for dependencies inside the set.
convert_apps is the list of apps to convert to use migrations
(i.e. to make initial migrations for, in the usual case)
graph is an optional argument that, if provided, can help improve
dependency generation and avoid potential circular dependencies.
"""
# The first phase is generating all the operations for each app
# and gathering them into a big per-app list.
# Then go through that list, order it, and split into migrations to
# resolve dependencies caused by M2Ms and FKs.
self.generated_operations = {}
self.altered_indexes = {}
# Prepare some old/new state and model lists, separating
# proxy models and ignoring unmigrated apps.
self.old_apps = self.from_state.concrete_apps
self.new_apps = self.to_state.apps
self.old_model_keys = set()
self.old_proxy_keys = set()
self.old_unmanaged_keys = set()
self.new_model_keys = set()
self.new_proxy_keys = set()
self.new_unmanaged_keys = set()
for al, mn in self.from_state.models:
model = self.old_apps.get_model(al, mn)
if not model._meta.managed:
self.old_unmanaged_keys.add((al, mn))
elif al not in self.from_state.real_apps:
if model._meta.proxy:
self.old_proxy_keys.add((al, mn))
else:
self.old_model_keys.add((al, mn))
for al, mn in self.to_state.models:
model = self.new_apps.get_model(al, mn)
if not model._meta.managed:
self.new_unmanaged_keys.add((al, mn))
elif (
al not in self.from_state.real_apps or
(convert_apps and al in convert_apps)
):
if model._meta.proxy:
self.new_proxy_keys.add((al, mn))
else:
self.new_model_keys.add((al, mn))
# Renames have to come first
self.generate_renamed_models()
# Prepare lists of fields and generate through model map
self._prepare_field_lists()
self._generate_through_model_map()
# Generate non-rename model operations
self.generate_deleted_models()
self.generate_created_models()
self.generate_deleted_proxies()
self.generate_created_proxies()
self.generate_altered_options()
self.generate_altered_managers()
# Create the altered indexes and store them in self.altered_indexes.
# This avoids the same computation in generate_removed_indexes()
# and generate_added_indexes().
self.create_altered_indexes()
# Generate index removal operations before field is removed
self.generate_removed_indexes()
# Generate field operations
self.generate_renamed_fields()
self.generate_removed_fields()
self.generate_added_fields()
self.generate_altered_fields()
self.generate_altered_unique_together()
self.generate_altered_index_together()
self.generate_added_indexes()
self.generate_altered_db_table()
self.generate_altered_order_with_respect_to()
self._sort_migrations()
self._build_migration_list(graph)
self._optimize_migrations()
return self.migrations
def _prepare_field_lists(self):
"""
Prepare field lists and a list of the fields that used through models
in the old state so dependencies can be made from the through model
deletion to the field that uses it.
"""
self.kept_model_keys = self.old_model_keys & self.new_model_keys
self.kept_proxy_keys = self.old_proxy_keys & self.new_proxy_keys
self.kept_unmanaged_keys = self.old_unmanaged_keys & self.new_unmanaged_keys
self.through_users = {}
self.old_field_keys = {
(app_label, model_name, x)
for app_label, model_name in self.kept_model_keys
for x, y in self.from_state.models[
app_label,
self.renamed_models.get((app_label, model_name), model_name)
].fields
}
self.new_field_keys = {
(app_label, model_name, x)
for app_label, model_name in self.kept_model_keys
for x, y in self.to_state.models[app_label, model_name].fields
}
def _generate_through_model_map(self):
"""Through model map generation."""
for app_label, model_name in sorted(self.old_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
for field_name, field in old_model_state.fields:
old_field = self.old_apps.get_model(app_label, old_model_name)._meta.get_field(field_name)
if (hasattr(old_field, "remote_field") and getattr(old_field.remote_field, "through", None) and
not old_field.remote_field.through._meta.auto_created):
through_key = (
old_field.remote_field.through._meta.app_label,
old_field.remote_field.through._meta.model_name,
)
self.through_users[through_key] = (app_label, old_model_name, field_name)
def _build_migration_list(self, graph=None):
"""
Chop the lists of operations up into migrations with dependencies on
each other. Do this by going through an app's list of operations until
one is found that has an outgoing dependency that isn't in another
app's migration yet (hasn't been chopped off its list). Then chop off
the operations before it into a migration and move onto the next app.
If the loops completes without doing anything, there's a circular
dependency (which _should_ be impossible as the operations are
all split at this point so they can't depend and be depended on).
"""
self.migrations = {}
num_ops = sum(len(x) for x in self.generated_operations.values())
chop_mode = False
while num_ops:
# On every iteration, we step through all the apps and see if there
# is a completed set of operations.
# If we find that a subset of the operations are complete we can
# try to chop it off from the rest and continue, but we only
# do this if we've already been through the list once before
# without any chopping and nothing has changed.
for app_label in sorted(self.generated_operations):
chopped = []
dependencies = set()
for operation in list(self.generated_operations[app_label]):
deps_satisfied = True
operation_dependencies = set()
for dep in operation._auto_deps:
is_swappable_dep = dep[0] == '__setting__'
if is_swappable_dep:
# We need to temporarily resolve the swappable dependency to prevent
# circular references. While keeping the dependency checks on the
# resolved model we still add the swappable dependencies.
# See #23322
resolved_app_label, resolved_object_name = getattr(settings, dep[1]).split('.')
original_dep = dep
dep = (resolved_app_label, resolved_object_name.lower(), dep[2], dep[3])
if dep[0] != app_label and dep[0] != "__setting__":
# External app dependency. See if it's not yet
# satisfied.
for other_operation in self.generated_operations.get(dep[0], []):
if self.check_dependency(other_operation, dep):
deps_satisfied = False
break
if not deps_satisfied:
break
else:
if is_swappable_dep:
operation_dependencies.add((original_dep[0], original_dep[1]))
elif dep[0] in self.migrations:
operation_dependencies.add((dep[0], self.migrations[dep[0]][-1].name))
else:
# If we can't find the other app, we add a first/last dependency,
# but only if we've already been through once and checked everything
if chop_mode:
# If the app already exists, we add a dependency on the last migration,
# as we don't know which migration contains the target field.
# If it's not yet migrated or has no migrations, we use __first__
if graph and graph.leaf_nodes(dep[0]):
operation_dependencies.add(graph.leaf_nodes(dep[0])[0])
else:
operation_dependencies.add((dep[0], "__first__"))
else:
deps_satisfied = False
if deps_satisfied:
chopped.append(operation)
dependencies.update(operation_dependencies)
del self.generated_operations[app_label][0]
else:
break
# Make a migration! Well, only if there's stuff to put in it
if dependencies or chopped:
if not self.generated_operations[app_label] or chop_mode:
subclass = type("Migration", (Migration,), {"operations": [], "dependencies": []})
instance = subclass("auto_%i" % (len(self.migrations.get(app_label, [])) + 1), app_label)
instance.dependencies = list(dependencies)
instance.operations = chopped
instance.initial = app_label not in self.existing_apps
self.migrations.setdefault(app_label, []).append(instance)
chop_mode = False
else:
self.generated_operations[app_label] = chopped + self.generated_operations[app_label]
new_num_ops = sum(len(x) for x in self.generated_operations.values())
if new_num_ops == num_ops:
if not chop_mode:
chop_mode = True
else:
raise ValueError("Cannot resolve operation dependencies: %r" % self.generated_operations)
num_ops = new_num_ops
def _sort_migrations(self):
"""
Reorder to make things possible. Reordering may be needed so FKs work
nicely inside the same app.
"""
for app_label, ops in sorted(self.generated_operations.items()):
# construct a dependency graph for intra-app dependencies
dependency_graph = {op: set() for op in ops}
for op in ops:
for dep in op._auto_deps:
if dep[0] == app_label:
for op2 in ops:
if self.check_dependency(op2, dep):
dependency_graph[op].add(op2)
# we use a stable sort for deterministic tests & general behavior
self.generated_operations[app_label] = stable_topological_sort(ops, dependency_graph)
def _optimize_migrations(self):
# Add in internal dependencies among the migrations
for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name))
# De-dupe dependencies
for migrations in self.migrations.values():
for migration in migrations:
migration.dependencies = list(set(migration.dependencies))
# Optimize migrations
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.operations = MigrationOptimizer().optimize(migration.operations, app_label=app_label)
def check_dependency(self, operation, dependency):
"""
Return True if the given operation depends on the given dependency,
False otherwise.
"""
# Created model
if dependency[2] is None and dependency[3] is True:
return (
isinstance(operation, operations.CreateModel) and
operation.name_lower == dependency[1].lower()
)
# Created field
elif dependency[2] is not None and dependency[3] is True:
return (
(
isinstance(operation, operations.CreateModel) and
operation.name_lower == dependency[1].lower() and
any(dependency[2] == x for x, y in operation.fields)
) or
(
isinstance(operation, operations.AddField) and
operation.model_name_lower == dependency[1].lower() and
operation.name_lower == dependency[2].lower()
)
)
# Removed field
elif dependency[2] is not None and dependency[3] is False:
return (
isinstance(operation, operations.RemoveField) and
operation.model_name_lower == dependency[1].lower() and
operation.name_lower == dependency[2].lower()
)
# Removed model
elif dependency[2] is None and dependency[3] is False:
return (
isinstance(operation, operations.DeleteModel) and
operation.name_lower == dependency[1].lower()
)
# Field being altered
elif dependency[2] is not None and dependency[3] == "alter":
return (
isinstance(operation, operations.AlterField) and
operation.model_name_lower == dependency[1].lower() and
operation.name_lower == dependency[2].lower()
)
# order_with_respect_to being unset for a field
elif dependency[2] is not None and dependency[3] == "order_wrt_unset":
return (
isinstance(operation, operations.AlterOrderWithRespectTo) and
operation.name_lower == dependency[1].lower() and
(operation.order_with_respect_to or "").lower() != dependency[2].lower()
)
# Field is removed and part of an index/unique_together
elif dependency[2] is not None and dependency[3] == "foo_together_change":
return (
isinstance(operation, (operations.AlterUniqueTogether,
operations.AlterIndexTogether)) and
operation.name_lower == dependency[1].lower()
)
# Unknown dependency. Raise an error.
else:
raise ValueError("Can't handle dependency %r" % (dependency,))
def add_operation(self, app_label, operation, dependencies=None, beginning=False):
# Dependencies are (app_label, model_name, field_name, create/delete as True/False)
operation._auto_deps = dependencies or []
if beginning:
self.generated_operations.setdefault(app_label, []).insert(0, operation)
else:
self.generated_operations.setdefault(app_label, []).append(operation)
def swappable_first_key(self, item):
"""
Place potential swappable models first in lists of created models (only
real way to solve #22783).
"""
try:
model = self.new_apps.get_model(item[0], item[1])
base_names = [base.__name__ for base in model.__bases__]
string_version = "%s.%s" % (item[0], item[1])
if (
model._meta.swappable or
"AbstractUser" in base_names or
"AbstractBaseUser" in base_names or
settings.AUTH_USER_MODEL.lower() == string_version.lower()
):
return ("___" + item[0], "___" + item[1])
except LookupError:
pass
return item
def generate_renamed_models(self):
"""
Find any renamed models, generate the operations for them, and remove
the old entry from the model lists. Must be run before other
model-level generation.
"""
self.renamed_models = {}
self.renamed_models_rel = {}
added_models = self.new_model_keys - self.old_model_keys
for app_label, model_name in sorted(added_models):
model_state = self.to_state.models[app_label, model_name]
model_fields_def = self.only_relation_agnostic_fields(model_state.fields)
removed_models = self.old_model_keys - self.new_model_keys
for rem_app_label, rem_model_name in removed_models:
if rem_app_label == app_label:
rem_model_state = self.from_state.models[rem_app_label, rem_model_name]
rem_model_fields_def = self.only_relation_agnostic_fields(rem_model_state.fields)
if model_fields_def == rem_model_fields_def:
if self.questioner.ask_rename_model(rem_model_state, model_state):
model_opts = self.new_apps.get_model(app_label, model_name)._meta
dependencies = []
for field in model_opts.get_fields():
if field.is_relation:
dependencies.extend(self._get_dependencies_for_foreign_key(field))
self.add_operation(
app_label,
operations.RenameModel(
old_name=rem_model_state.name,
new_name=model_state.name,
),
dependencies=dependencies,
)
self.renamed_models[app_label, model_name] = rem_model_name
renamed_models_rel_key = '%s.%s' % (rem_model_state.app_label, rem_model_state.name)
self.renamed_models_rel[renamed_models_rel_key] = '%s.%s' % (
model_state.app_label,
model_state.name,
)
self.old_model_keys.remove((rem_app_label, rem_model_name))
self.old_model_keys.add((app_label, model_name))
break
def generate_created_models(self):
"""
Find all new models (both managed and unmanaged) and make create
operations for them as well as separate operations to create any
foreign key or M2M relationships (these are optimized later, if
possible).
Defer any model options that refer to collections of fields that might
be deferred (e.g. unique_together, index_together).
"""
old_keys = self.old_model_keys | self.old_unmanaged_keys
added_models = self.new_model_keys - old_keys
added_unmanaged_models = self.new_unmanaged_keys - old_keys
all_added_models = chain(
sorted(added_models, key=self.swappable_first_key, reverse=True),
sorted(added_unmanaged_models, key=self.swappable_first_key, reverse=True)
)
for app_label, model_name in all_added_models:
model_state = self.to_state.models[app_label, model_name]
model_opts = self.new_apps.get_model(app_label, model_name)._meta
# Gather related fields
related_fields = {}
primary_key_rel = None
for field in model_opts.local_fields:
if field.remote_field:
if field.remote_field.model:
if field.primary_key:
primary_key_rel = field.remote_field.model
elif not field.remote_field.parent_link:
related_fields[field.name] = field
# through will be none on M2Ms on swapped-out models;
# we can treat lack of through as auto_created=True, though.
if (getattr(field.remote_field, "through", None) and
not field.remote_field.through._meta.auto_created):
related_fields[field.name] = field
for field in model_opts.local_many_to_many:
if field.remote_field.model:
related_fields[field.name] = field
if getattr(field.remote_field, "through", None) and not field.remote_field.through._meta.auto_created:
related_fields[field.name] = field
# Are there indexes/unique|index_together to defer?
indexes = model_state.options.pop('indexes')
unique_together = model_state.options.pop('unique_together', None)
index_together = model_state.options.pop('index_together', None)
order_with_respect_to = model_state.options.pop('order_with_respect_to', None)
# Depend on the deletion of any possible proxy version of us
dependencies = [
(app_label, model_name, None, False),
]
# Depend on all bases
for base in model_state.bases:
if isinstance(base, str) and "." in base:
base_app_label, base_name = base.split(".", 1)
dependencies.append((base_app_label, base_name, None, True))
# Depend on the other end of the primary key if it's a relation
if primary_key_rel:
dependencies.append((
primary_key_rel._meta.app_label,
primary_key_rel._meta.object_name,
None,
True
))
# Generate creation operation
self.add_operation(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[d for d in model_state.fields if d[0] not in related_fields],
options=model_state.options,
bases=model_state.bases,
managers=model_state.managers,
),
dependencies=dependencies,
beginning=True,
)
# Don't add operations which modify the database for unmanaged models
if not model_opts.managed:
continue
# Generate operations for each related field
for name, field in sorted(related_fields.items()):
dependencies = self._get_dependencies_for_foreign_key(field)
# Depend on our own model being created
dependencies.append((app_label, model_name, None, True))
# Make operation
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=name,
field=field,
),
dependencies=list(set(dependencies)),
)
# Generate other opns
related_dependencies = [
(app_label, model_name, name, True)
for name in sorted(related_fields)
]
related_dependencies.append((app_label, model_name, None, True))
for index in indexes:
self.add_operation(
app_label,
operations.AddIndex(
model_name=model_name,
index=index,
),
dependencies=related_dependencies,
)
if unique_together:
self.add_operation(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=unique_together,
),
dependencies=related_dependencies
)
if index_together:
self.add_operation(
app_label,
operations.AlterIndexTogether(
name=model_name,
index_together=index_together,
),
dependencies=related_dependencies
)
if order_with_respect_to:
self.add_operation(
app_label,
operations.AlterOrderWithRespectTo(
name=model_name,
order_with_respect_to=order_with_respect_to,
),
dependencies=[
(app_label, model_name, order_with_respect_to, True),
(app_label, model_name, None, True),
]
)
# Fix relationships if the model changed from a proxy model to a
# concrete model.
if (app_label, model_name) in self.old_proxy_keys:
for related_object in model_opts.related_objects:
self.add_operation(
related_object.related_model._meta.app_label,
operations.AlterField(
model_name=related_object.related_model._meta.object_name,
name=related_object.field.name,
field=related_object.field,
),
dependencies=[(app_label, model_name, None, True)],
)
def generate_created_proxies(self):
"""
Make CreateModel statements for proxy models. Use the same statements
as that way there's less code duplication, but of course for proxy
models it's safe to skip all the pointless field stuff and just chuck
out an operation.
"""
added = self.new_proxy_keys - self.old_proxy_keys
for app_label, model_name in sorted(added):
model_state = self.to_state.models[app_label, model_name]
assert model_state.options.get("proxy")
# Depend on the deletion of any possible non-proxy version of us
dependencies = [
(app_label, model_name, None, False),
]
# Depend on all bases
for base in model_state.bases:
if isinstance(base, str) and "." in base:
base_app_label, base_name = base.split(".", 1)
dependencies.append((base_app_label, base_name, None, True))
# Generate creation operation
self.add_operation(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[],
options=model_state.options,
bases=model_state.bases,
managers=model_state.managers,
),
# Depend on the deletion of any possible non-proxy version of us
dependencies=dependencies,
)
def generate_deleted_models(self):
"""
Find all deleted models (managed and unmanaged) and make delete
operations for them as well as separate operations to delete any
foreign key or M2M relationships (these are optimized later, if
possible).
Also bring forward removal of any model options that refer to
collections of fields - the inverse of generate_created_models().
"""
new_keys = self.new_model_keys | self.new_unmanaged_keys
deleted_models = self.old_model_keys - new_keys
deleted_unmanaged_models = self.old_unmanaged_keys - new_keys
all_deleted_models = chain(sorted(deleted_models), sorted(deleted_unmanaged_models))
for app_label, model_name in all_deleted_models:
model_state = self.from_state.models[app_label, model_name]
model = self.old_apps.get_model(app_label, model_name)
if not model._meta.managed:
# Skip here, no need to handle fields for unmanaged models
continue
# Gather related fields
related_fields = {}
for field in model._meta.local_fields:
if field.remote_field:
if field.remote_field.model:
related_fields[field.name] = field
# through will be none on M2Ms on swapped-out models;
# we can treat lack of through as auto_created=True, though.
if (getattr(field.remote_field, "through", None) and
not field.remote_field.through._meta.auto_created):
related_fields[field.name] = field
for field in model._meta.local_many_to_many:
if field.remote_field.model:
related_fields[field.name] = field
if getattr(field.remote_field, "through", None) and not field.remote_field.through._meta.auto_created:
related_fields[field.name] = field
# Generate option removal first
unique_together = model_state.options.pop('unique_together', None)
index_together = model_state.options.pop('index_together', None)
if unique_together:
self.add_operation(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=None,
)
)
if index_together:
self.add_operation(
app_label,
operations.AlterIndexTogether(
name=model_name,
index_together=None,
)
)
# Then remove each related field
for name in sorted(related_fields):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=name,
)
)
# Finally, remove the model.
# This depends on both the removal/alteration of all incoming fields
# and the removal of all its own related fields, and if it's
# a through model the field that references it.
dependencies = []
for related_object in model._meta.related_objects:
related_object_app_label = related_object.related_model._meta.app_label
object_name = related_object.related_model._meta.object_name
field_name = related_object.field.name
dependencies.append((related_object_app_label, object_name, field_name, False))
if not related_object.many_to_many:
dependencies.append((related_object_app_label, object_name, field_name, "alter"))
for name in sorted(related_fields):
dependencies.append((app_label, model_name, name, False))
# We're referenced in another field's through=
through_user = self.through_users.get((app_label, model_state.name_lower))
if through_user:
dependencies.append((through_user[0], through_user[1], through_user[2], False))
# Finally, make the operation, deduping any dependencies
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
dependencies=list(set(dependencies)),
)
def generate_deleted_proxies(self):
"""Make DeleteModel options for proxy models."""
deleted = self.old_proxy_keys - self.new_proxy_keys
for app_label, model_name in sorted(deleted):
model_state = self.from_state.models[app_label, model_name]
assert model_state.options.get("proxy")
self.add_operation(
app_label,
operations.DeleteModel(
name=model_state.name,
),
)
def generate_renamed_fields(self):
"""Work out renamed fields."""
self.renamed_fields = {}
for app_label, model_name, field_name in sorted(self.new_field_keys - self.old_field_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
field = self.new_apps.get_model(app_label, model_name)._meta.get_field(field_name)
# Scan to see if this is actually a rename!
field_dec = self.deep_deconstruct(field)
for rem_app_label, rem_model_name, rem_field_name in sorted(self.old_field_keys - self.new_field_keys):
if rem_app_label == app_label and rem_model_name == model_name:
old_field = old_model_state.get_field_by_name(rem_field_name)
old_field_dec = self.deep_deconstruct(old_field)
if field.remote_field and field.remote_field.model and 'to' in old_field_dec[2]:
old_rel_to = old_field_dec[2]['to']
if old_rel_to in self.renamed_models_rel:
old_field_dec[2]['to'] = self.renamed_models_rel[old_rel_to]
old_field.set_attributes_from_name(rem_field_name)
old_db_column = old_field.get_attname_column()[1]
if (old_field_dec == field_dec or (
# Was the field renamed and db_column equal to the
# old field's column added?
old_field_dec[0:2] == field_dec[0:2] and
dict(old_field_dec[2], db_column=old_db_column) == field_dec[2])):
if self.questioner.ask_rename(model_name, rem_field_name, field_name, field):
self.add_operation(
app_label,
operations.RenameField(
model_name=model_name,
old_name=rem_field_name,
new_name=field_name,
)
)
self.old_field_keys.remove((rem_app_label, rem_model_name, rem_field_name))
self.old_field_keys.add((app_label, model_name, field_name))
self.renamed_fields[app_label, model_name, field_name] = rem_field_name
break
def generate_added_fields(self):
"""Make AddField operations."""
for app_label, model_name, field_name in sorted(self.new_field_keys - self.old_field_keys):
self._generate_added_field(app_label, model_name, field_name)
def _generate_added_field(self, app_label, model_name, field_name):
field = self.new_apps.get_model(app_label, model_name)._meta.get_field(field_name)
# Fields that are foreignkeys/m2ms depend on stuff
dependencies = []
if field.remote_field and field.remote_field.model:
dependencies.extend(self._get_dependencies_for_foreign_key(field))
# You can't just add NOT NULL fields with no default or fields
# which don't allow empty strings as default.
time_fields = (models.DateField, models.DateTimeField, models.TimeField)
preserve_default = (
field.null or field.has_default() or field.many_to_many or
(field.blank and field.empty_strings_allowed) or
(isinstance(field, time_fields) and field.auto_now)
)
if not preserve_default:
field = field.clone()
if isinstance(field, time_fields) and field.auto_now_add:
field.default = self.questioner.ask_auto_now_add_addition(field_name, model_name)
else:
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
),
dependencies=dependencies,
)
def generate_removed_fields(self):
"""Make RemoveField operations."""
for app_label, model_name, field_name in sorted(self.old_field_keys - self.new_field_keys):
self._generate_removed_field(app_label, model_name, field_name)
def _generate_removed_field(self, app_label, model_name, field_name):
self.add_operation(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
),
# We might need to depend on the removal of an
# order_with_respect_to or index/unique_together operation;
# this is safely ignored if there isn't one
dependencies=[
(app_label, model_name, field_name, "order_wrt_unset"),
(app_label, model_name, field_name, "foo_together_change"),
],
)
def generate_altered_fields(self):
"""
Make AlterField operations, or possibly RemovedField/AddField if alter
isn's possible.
"""
for app_label, model_name, field_name in sorted(self.old_field_keys & self.new_field_keys):
# Did the field change?
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_field_name = self.renamed_fields.get((app_label, model_name, field_name), field_name)
old_field = self.old_apps.get_model(app_label, old_model_name)._meta.get_field(old_field_name)
new_field = self.new_apps.get_model(app_label, model_name)._meta.get_field(field_name)
# Implement any model renames on relations; these are handled by RenameModel
# so we need to exclude them from the comparison
if hasattr(new_field, "remote_field") and getattr(new_field.remote_field, "model", None):
rename_key = (
new_field.remote_field.model._meta.app_label,
new_field.remote_field.model._meta.model_name,
)
if rename_key in self.renamed_models:
new_field.remote_field.model = old_field.remote_field.model
# Handle ForeignKey which can only have a single to_field.
remote_field_name = getattr(new_field.remote_field, 'field_name', None)
if remote_field_name:
to_field_rename_key = rename_key + (remote_field_name,)
if to_field_rename_key in self.renamed_fields:
new_field.remote_field.field_name = old_field.remote_field.field_name
# Handle ForeignObjects which can have multiple from_fields/to_fields.
from_fields = getattr(new_field, 'from_fields', None)
if from_fields:
from_rename_key = (app_label, model_name)
new_field.from_fields = tuple([
self.renamed_fields.get(from_rename_key + (from_field,), from_field)
for from_field in from_fields
])
new_field.to_fields = tuple([
self.renamed_fields.get(rename_key + (to_field,), to_field)
for to_field in new_field.to_fields
])
if hasattr(new_field, "remote_field") and getattr(new_field.remote_field, "through", None):
rename_key = (
new_field.remote_field.through._meta.app_label,
new_field.remote_field.through._meta.model_name,
)
if rename_key in self.renamed_models:
new_field.remote_field.through = old_field.remote_field.through
old_field_dec = self.deep_deconstruct(old_field)
new_field_dec = self.deep_deconstruct(new_field)
if old_field_dec != new_field_dec:
both_m2m = old_field.many_to_many and new_field.many_to_many
neither_m2m = not old_field.many_to_many and not new_field.many_to_many
if both_m2m or neither_m2m:
# Either both fields are m2m or neither is
preserve_default = True
if (old_field.null and not new_field.null and not new_field.has_default() and
not new_field.many_to_many):
field = new_field.clone()
new_default = self.questioner.ask_not_null_alteration(field_name, model_name)
if new_default is not models.NOT_PROVIDED:
field.default = new_default
preserve_default = False
else:
field = new_field
self.add_operation(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=preserve_default,
)
)
else:
# We cannot alter between m2m and concrete fields
self._generate_removed_field(app_label, model_name, field_name)
self._generate_added_field(app_label, model_name, field_name)
def create_altered_indexes(self):
option_name = operations.AddIndex.option_name
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_indexes = old_model_state.options[option_name]
new_indexes = new_model_state.options[option_name]
add_idx = [idx for idx in new_indexes if idx not in old_indexes]
rem_idx = [idx for idx in old_indexes if idx not in new_indexes]
self.altered_indexes.update({
(app_label, model_name): {
'added_indexes': add_idx, 'removed_indexes': rem_idx,
}
})
def generate_added_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for index in alt_indexes['added_indexes']:
self.add_operation(
app_label,
operations.AddIndex(
model_name=model_name,
index=index,
)
)
def generate_removed_indexes(self):
for (app_label, model_name), alt_indexes in self.altered_indexes.items():
for index in alt_indexes['removed_indexes']:
self.add_operation(
app_label,
operations.RemoveIndex(
model_name=model_name,
name=index.name,
)
)
def _get_dependencies_for_foreign_key(self, field):
# Account for FKs to swappable models
swappable_setting = getattr(field, 'swappable_setting', None)
if swappable_setting is not None:
dep_app_label = "__setting__"
dep_object_name = swappable_setting
else:
dep_app_label = field.remote_field.model._meta.app_label
dep_object_name = field.remote_field.model._meta.object_name
dependencies = [(dep_app_label, dep_object_name, None, True)]
if getattr(field.remote_field, "through", None) and not field.remote_field.through._meta.auto_created:
dependencies.append((
field.remote_field.through._meta.app_label,
field.remote_field.through._meta.object_name,
None,
True,
))
return dependencies
def _generate_altered_foo_together(self, operation):
option_name = operation.option_name
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
# We run the old version through the field renames to account for those
old_value = old_model_state.options.get(option_name)
old_value = {
tuple(
self.renamed_fields.get((app_label, model_name, n), n)
for n in unique
)
for unique in old_value
} if old_value else set()
new_value = new_model_state.options.get(option_name)
new_value = set(new_value) if new_value else set()
if old_value != new_value:
dependencies = []
for foo_togethers in new_value:
for field_name in foo_togethers:
field = self.new_apps.get_model(app_label, model_name)._meta.get_field(field_name)
if field.remote_field and field.remote_field.model:
dependencies.extend(self._get_dependencies_for_foreign_key(field))
self.add_operation(
app_label,
operation(
name=model_name,
**{option_name: new_value}
),
dependencies=dependencies,
)
def generate_altered_unique_together(self):
self._generate_altered_foo_together(operations.AlterUniqueTogether)
def generate_altered_index_together(self):
self._generate_altered_foo_together(operations.AlterIndexTogether)
def generate_altered_db_table(self):
models_to_check = self.kept_model_keys.union(self.kept_proxy_keys, self.kept_unmanaged_keys)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_db_table_name = old_model_state.options.get('db_table')
new_db_table_name = new_model_state.options.get('db_table')
if old_db_table_name != new_db_table_name:
self.add_operation(
app_label,
operations.AlterModelTable(
name=model_name,
table=new_db_table_name,
)
)
def generate_altered_options(self):
"""
Work out if any non-schema-affecting options have changed and make an
operation to represent them in state changes (in case Python code in
migrations needs them).
"""
models_to_check = self.kept_model_keys.union(
self.kept_proxy_keys,
self.kept_unmanaged_keys,
# unmanaged converted to managed
self.old_unmanaged_keys & self.new_model_keys,
# managed converted to unmanaged
self.old_model_keys & self.new_unmanaged_keys,
)
for app_label, model_name in sorted(models_to_check):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_options = {
key: value for key, value in old_model_state.options.items()
if key in AlterModelOptions.ALTER_OPTION_KEYS
}
new_options = {
key: value for key, value in new_model_state.options.items()
if key in AlterModelOptions.ALTER_OPTION_KEYS
}
if old_options != new_options:
self.add_operation(
app_label,
operations.AlterModelOptions(
name=model_name,
options=new_options,
)
)
def generate_altered_order_with_respect_to(self):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
if (old_model_state.options.get("order_with_respect_to") !=
new_model_state.options.get("order_with_respect_to")):
# Make sure it comes second if we're adding
# (removal dependency is part of RemoveField)
dependencies = []
if new_model_state.options.get("order_with_respect_to"):
dependencies.append((
app_label,
model_name,
new_model_state.options["order_with_respect_to"],
True,
))
# Actually generate the operation
self.add_operation(
app_label,
operations.AlterOrderWithRespectTo(
name=model_name,
order_with_respect_to=new_model_state.options.get('order_with_respect_to'),
),
dependencies=dependencies,
)
def generate_altered_managers(self):
for app_label, model_name in sorted(self.kept_model_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
if old_model_state.managers != new_model_state.managers:
self.add_operation(
app_label,
operations.AlterModelManagers(
name=model_name,
managers=new_model_state.managers,
)
)
def arrange_for_graph(self, changes, graph, migration_name=None):
"""
Take a result from changes() and a MigrationGraph, and fix the names
and dependencies of the changes so they extend the graph from the leaf
nodes for each app.
"""
leaves = graph.leaf_nodes()
name_map = {}
for app_label, migrations in list(changes.items()):
if not migrations:
continue
# Find the app label's current leaf node
app_leaf = None
for leaf in leaves:
if leaf[0] == app_label:
app_leaf = leaf
break
# Do they want an initial migration for this app?
if app_leaf is None and not self.questioner.ask_initial(app_label):
# They don't.
for migration in migrations:
name_map[(app_label, migration.name)] = (app_label, "__first__")
del changes[app_label]
continue
# Work out the next number in the sequence
if app_leaf is None:
next_number = 1
else:
next_number = (self.parse_number(app_leaf[1]) or 0) + 1
# Name each migration
for i, migration in enumerate(migrations):
if i == 0 and app_leaf:
migration.dependencies.append(app_leaf)
if i == 0 and not app_leaf:
new_name = "0001_%s" % migration_name if migration_name else "0001_initial"
else:
new_name = "%04i_%s" % (
next_number,
migration_name or self.suggest_name(migration.operations)[:100],
)
name_map[(app_label, migration.name)] = (app_label, new_name)
next_number += 1
migration.name = new_name
# Now fix dependencies
for migrations in changes.values():
for migration in migrations:
migration.dependencies = [name_map.get(d, d) for d in migration.dependencies]
return changes
def _trim_to_apps(self, changes, app_labels):
"""
Take changes from arrange_for_graph() and set of app labels, and return
a modified set of changes which trims out as many migrations that are
not in app_labels as possible. Note that some other migrations may
still be present as they may be required dependencies.
"""
# Gather other app dependencies in a first pass
app_dependencies = {}
for app_label, migrations in changes.items():
for migration in migrations:
for dep_app_label, name in migration.dependencies:
app_dependencies.setdefault(app_label, set()).add(dep_app_label)
required_apps = set(app_labels)
# Keep resolving till there's no change
old_required_apps = None
while old_required_apps != required_apps:
old_required_apps = set(required_apps)
required_apps.update(*[app_dependencies.get(app_label, ()) for app_label in required_apps])
# Remove all migrations that aren't needed
for app_label in list(changes):
if app_label not in required_apps:
del changes[app_label]
return changes
@classmethod
def suggest_name(cls, ops):
"""
Given a set of operations, suggest a name for the migration they might
represent. Names are not guaranteed to be unique, but put some effort
into the fallback name to avoid VCS conflicts if possible.
"""
if len(ops) == 1:
if isinstance(ops[0], operations.CreateModel):
return ops[0].name_lower
elif isinstance(ops[0], operations.DeleteModel):
return "delete_%s" % ops[0].name_lower
elif isinstance(ops[0], operations.AddField):
return "%s_%s" % (ops[0].model_name_lower, ops[0].name_lower)
elif isinstance(ops[0], operations.RemoveField):
return "remove_%s_%s" % (ops[0].model_name_lower, ops[0].name_lower)
elif ops:
if all(isinstance(o, operations.CreateModel) for o in ops):
return "_".join(sorted(o.name_lower for o in ops))
return "auto_%s" % get_migration_name_timestamp()
@classmethod
def parse_number(cls, name):
"""
Given a migration name, try to extract a number from the beginning of
it. If no number is found, return None.
"""
match = re.match(r'^\d+', name)
if match:
return int(match.group())
return None
|
a8af5f6945ea4693eb67cbe743cb776de04b547cea5f9420172a1b89635192a2 | from django.db.transaction import atomic
from .exceptions import IrreversibleError
class Migration:
"""
The base class for all migrations.
Migration files will import this from django.db.migrations.Migration
and subclass it as a class called Migration. It will have one or more
of the following attributes:
- operations: A list of Operation instances, probably from django.db.migrations.operations
- dependencies: A list of tuples of (app_path, migration_name)
- run_before: A list of tuples of (app_path, migration_name)
- replaces: A list of migration_names
Note that all migrations come out of migrations and into the Loader or
Graph as instances, having been initialized with their app label and name.
"""
# Operations to apply during this migration, in order.
operations = []
# Other migrations that should be run before this migration.
# Should be a list of (app, migration_name).
dependencies = []
# Other migrations that should be run after this one (i.e. have
# this migration added to their dependencies). Useful to make third-party
# apps' migrations run after your AUTH_USER replacement, for example.
run_before = []
# Migration names in this app that this migration replaces. If this is
# non-empty, this migration will only be applied if all these migrations
# are not applied.
replaces = []
# Is this an initial migration? Initial migrations are skipped on
# --fake-initial if the table or fields already exist. If None, check if
# the migration has any dependencies to determine if there are dependencies
# to tell if db introspection needs to be done. If True, always perform
# introspection. If False, never perform introspection.
initial = None
# Whether to wrap the whole migration in a transaction. Only has an effect
# on database backends which support transactional DDL.
atomic = True
def __init__(self, name, app_label):
self.name = name
self.app_label = app_label
# Copy dependencies & other attrs as we might mutate them at runtime
self.operations = list(self.__class__.operations)
self.dependencies = list(self.__class__.dependencies)
self.run_before = list(self.__class__.run_before)
self.replaces = list(self.__class__.replaces)
def __eq__(self, other):
return (
isinstance(other, Migration) and
self.name == other.name and
self.app_label == other.app_label
)
def __repr__(self):
return "<Migration %s.%s>" % (self.app_label, self.name)
def __str__(self):
return "%s.%s" % (self.app_label, self.name)
def __hash__(self):
return hash("%s.%s" % (self.app_label, self.name))
def mutate_state(self, project_state, preserve=True):
"""
Take a ProjectState and return a new one with the migration's
operations applied to it. Preserve the original object state by
default and return a mutated state from a copy.
"""
new_state = project_state
if preserve:
new_state = project_state.clone()
for operation in self.operations:
operation.state_forwards(self.app_label, new_state)
return new_state
def apply(self, project_state, schema_editor, collect_sql=False):
"""
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration
in a forwards order.
Return the resulting project state for efficient reuse by following
Migrations.
"""
for operation in self.operations:
# If this operation cannot be represented as SQL, place a comment
# there instead
if collect_sql:
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
schema_editor.collected_sql.append(
"-- MIGRATION NOW PERFORMS OPERATION THAT CANNOT BE WRITTEN AS SQL:"
)
schema_editor.collected_sql.append("-- %s" % operation.describe())
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
continue
# Save the state before the operation has run
old_state = project_state.clone()
operation.state_forwards(self.app_label, project_state)
# Run the operation
atomic_operation = operation.atomic or (self.atomic and operation.atomic is not False)
if not schema_editor.atomic_migration and atomic_operation:
# Force a transaction on a non-transactional-DDL backend or an
# atomic operation inside a non-atomic migration.
with atomic(schema_editor.connection.alias):
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
else:
# Normal behaviour
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
return project_state
def unapply(self, project_state, schema_editor, collect_sql=False):
"""
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration
in a reverse order.
The backwards migration process consists of two phases:
1. The intermediate states from right before the first until right
after the last operation inside this migration are preserved.
2. The operations are applied in reverse order using the states
recorded in step 1.
"""
# Construct all the intermediate states we need for a reverse migration
to_run = []
new_state = project_state
# Phase 1
for operation in self.operations:
# If it's irreversible, error out
if not operation.reversible:
raise IrreversibleError("Operation %s in %s is not reversible" % (operation, self))
# Preserve new state from previous run to not tamper the same state
# over all operations
new_state = new_state.clone()
old_state = new_state.clone()
operation.state_forwards(self.app_label, new_state)
to_run.insert(0, (operation, old_state, new_state))
# Phase 2
for operation, to_state, from_state in to_run:
if collect_sql:
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
schema_editor.collected_sql.append(
"-- MIGRATION NOW PERFORMS OPERATION THAT CANNOT BE WRITTEN AS SQL:"
)
schema_editor.collected_sql.append("-- %s" % operation.describe())
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
continue
atomic_operation = operation.atomic or (self.atomic and operation.atomic is not False)
if not schema_editor.atomic_migration and atomic_operation:
# Force a transaction on a non-transactional-DDL backend or an
# atomic operation inside a non-atomic migration.
with atomic(schema_editor.connection.alias):
operation.database_backwards(self.app_label, schema_editor, from_state, to_state)
else:
# Normal behaviour
operation.database_backwards(self.app_label, schema_editor, from_state, to_state)
return project_state
class SwappableTuple(tuple):
"""
Subclass of tuple so Django can tell this was originally a swappable
dependency when it reads the migration file.
"""
def __new__(cls, value, setting):
self = tuple.__new__(cls, value)
self.setting = setting
return self
def swappable_dependency(value):
"""Turn a setting value into a dependency."""
return SwappableTuple((value.split(".", 1)[0], "__first__"), value)
|
02920856136b9e767bf72ceb6cf791105b24e64c4b0ae39dd6bc21ddd0da34b2 | import datetime
import re
COMPILED_REGEX_TYPE = type(re.compile(''))
class RegexObject:
def __init__(self, obj):
self.pattern = obj.pattern
self.flags = obj.flags
def __eq__(self, other):
return self.pattern == other.pattern and self.flags == other.flags
def get_migration_name_timestamp():
return datetime.datetime.now().strftime("%Y%m%d_%H%M")
|
615f550762165fd9f841fdc4b99cabcaed8e1c6232dacc9a729696e0b364b487 | from django.apps.registry import Apps
from django.db import models
from django.db.utils import DatabaseError
from django.utils.timezone import now
from .exceptions import MigrationSchemaMissing
class MigrationRecorder:
"""
Deal with storing migration records in the database.
Because this table is actually itself used for dealing with model
creation, it's the one thing we can't do normally via migrations.
We manually handle table creation/schema updating (using schema backend)
and then have a floating model to do queries with.
If a migration is unapplied its row is removed from the table. Having
a row in the table always means a migration is applied.
"""
class Migration(models.Model):
app = models.CharField(max_length=255)
name = models.CharField(max_length=255)
applied = models.DateTimeField(default=now)
class Meta:
apps = Apps()
app_label = "migrations"
db_table = "django_migrations"
def __str__(self):
return "Migration %s for %s" % (self.name, self.app)
def __init__(self, connection):
self.connection = connection
@property
def migration_qs(self):
return self.Migration.objects.using(self.connection.alias)
def has_table(self):
"""Return True if the django_migrations table exists."""
return self.Migration._meta.db_table in self.connection.introspection.table_names(self.connection.cursor())
def ensure_schema(self):
"""Ensure the table exists and has the correct schema."""
# If the table's there, that's fine - we've never changed its schema
# in the codebase.
if self.has_table():
return
# Make the table
try:
with self.connection.schema_editor() as editor:
editor.create_model(self.Migration)
except DatabaseError as exc:
raise MigrationSchemaMissing("Unable to create the django_migrations table (%s)" % exc)
def applied_migrations(self):
"""Return a set of (app, name) of applied migrations."""
if self.has_table():
return {tuple(x) for x in self.migration_qs.values_list('app', 'name')}
else:
# If the django_migrations table doesn't exist, then no migrations
# are applied.
return set()
def record_applied(self, app, name):
"""Record that a migration was applied."""
self.ensure_schema()
self.migration_qs.create(app=app, name=name)
def record_unapplied(self, app, name):
"""Record that a migration was unapplied."""
self.ensure_schema()
self.migration_qs.filter(app=app, name=name).delete()
def flush(self):
"""Delete all migration records. Useful for testing migrations."""
self.migration_qs.all().delete()
|
73676dd2de0039528b382618599266f42d08b5e5734e40fc0fbaf62e1e00f221 | class MigrationOptimizer:
"""
Power the optimization process, where you provide a list of Operations
and you are returned a list of equal or shorter length - operations
are merged into one if possible.
For example, a CreateModel and an AddField can be optimized into a
new CreateModel, and CreateModel and DeleteModel can be optimized into
nothing.
"""
def optimize(self, operations, app_label=None):
"""
Main optimization entry point. Pass in a list of Operation instances,
get out a new list of Operation instances.
Unfortunately, due to the scope of the optimization (two combinable
operations might be separated by several hundred others), this can't be
done as a peephole optimization with checks/output implemented on
the Operations themselves; instead, the optimizer looks at each
individual operation and scans forwards in the list to see if there
are any matches, stopping at boundaries - operations which can't
be optimized over (RunSQL, operations on the same field/model, etc.)
The inner loop is run until the starting list is the same as the result
list, and then the result is returned. This means that operation
optimization must be stable and always return an equal or shorter list.
The app_label argument is optional, but if you pass it you'll get more
efficient optimization.
"""
# Internal tracking variable for test assertions about # of loops
self._iterations = 0
while True:
result = self.optimize_inner(operations, app_label)
self._iterations += 1
if result == operations:
return result
operations = result
def optimize_inner(self, operations, app_label=None):
"""Inner optimization loop."""
new_operations = []
for i, operation in enumerate(operations):
# Compare it to each operation after it
for j, other in enumerate(operations[i + 1:]):
in_between = operations[i + 1:i + j + 1]
result = operation.reduce(other, in_between, app_label)
if isinstance(result, list):
# Optimize! Add result, then remaining others, then return
new_operations.extend(result)
new_operations.extend(in_between)
new_operations.extend(operations[i + j + 2:])
return new_operations
if not result:
# We can't optimize across `other`.
new_operations.append(operation)
break
else:
new_operations.append(operation)
return new_operations
|
23b1bd61f275c393f5d450c8361b0297dde6ee7bc0de49fcd63d22ce600d5d65 | import builtins
import collections.abc
import datetime
import decimal
import enum
import functools
import math
import re
import types
import uuid
from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.utils import COMPILED_REGEX_TYPE, RegexObject
from django.utils import datetime_safe
from django.utils.functional import LazyObject, Promise
from django.utils.timezone import utc
from django.utils.version import get_docs_version
class BaseSerializer:
def __init__(self, value):
self.value = value
def serialize(self):
raise NotImplementedError('Subclasses of BaseSerializer must implement the serialize() method.')
class BaseSequenceSerializer(BaseSerializer):
def _format(self):
raise NotImplementedError('Subclasses of BaseSequenceSerializer must implement the _format() method.')
def serialize(self):
imports = set()
strings = []
for item in self.value:
item_string, item_imports = serializer_factory(item).serialize()
imports.update(item_imports)
strings.append(item_string)
value = self._format()
return value % (", ".join(strings)), imports
class BaseSimpleSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), set()
class DatetimeSerializer(BaseSerializer):
def serialize(self):
if self.value.tzinfo is not None and self.value.tzinfo != utc:
self.value = self.value.astimezone(utc)
value_repr = repr(self.value).replace("datetime.timezone(datetime.timedelta(0), 'UTC')", 'utc')
if isinstance(self.value, datetime_safe.datetime):
value_repr = "datetime.%s" % value_repr
imports = ["import datetime"]
if self.value.tzinfo is not None:
imports.append("from django.utils.timezone import utc")
return value_repr, set(imports)
class DateSerializer(BaseSerializer):
def serialize(self):
value_repr = repr(self.value)
if isinstance(self.value, datetime_safe.date):
value_repr = "datetime.%s" % value_repr
return value_repr, {"import datetime"}
class DecimalSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), {"from decimal import Decimal"}
class DeconstructableSerializer(BaseSerializer):
@staticmethod
def serialize_deconstructed(path, args, kwargs):
name, imports = DeconstructableSerializer._serialize_path(path)
strings = []
for arg in args:
arg_string, arg_imports = serializer_factory(arg).serialize()
strings.append(arg_string)
imports.update(arg_imports)
for kw, arg in sorted(kwargs.items()):
arg_string, arg_imports = serializer_factory(arg).serialize()
imports.update(arg_imports)
strings.append("%s=%s" % (kw, arg_string))
return "%s(%s)" % (name, ", ".join(strings)), imports
@staticmethod
def _serialize_path(path):
module, name = path.rsplit(".", 1)
if module == "django.db.models":
imports = {"from django.db import models"}
name = "models.%s" % name
else:
imports = {"import %s" % module}
name = path
return name, imports
def serialize(self):
return self.serialize_deconstructed(*self.value.deconstruct())
class DictionarySerializer(BaseSerializer):
def serialize(self):
imports = set()
strings = []
for k, v in sorted(self.value.items()):
k_string, k_imports = serializer_factory(k).serialize()
v_string, v_imports = serializer_factory(v).serialize()
imports.update(k_imports)
imports.update(v_imports)
strings.append((k_string, v_string))
return "{%s}" % (", ".join("%s: %s" % (k, v) for k, v in strings)), imports
class EnumSerializer(BaseSerializer):
def serialize(self):
enum_class = self.value.__class__
module = enum_class.__module__
v_string, v_imports = serializer_factory(self.value.value).serialize()
imports = {'import %s' % module, *v_imports}
return "%s.%s(%s)" % (module, enum_class.__name__, v_string), imports
class FloatSerializer(BaseSimpleSerializer):
def serialize(self):
if math.isnan(self.value) or math.isinf(self.value):
return 'float("{}")'.format(self.value), set()
return super().serialize()
class FrozensetSerializer(BaseSequenceSerializer):
def _format(self):
return "frozenset([%s])"
class FunctionTypeSerializer(BaseSerializer):
def serialize(self):
if getattr(self.value, "__self__", None) and isinstance(self.value.__self__, type):
klass = self.value.__self__
module = klass.__module__
return "%s.%s.%s" % (module, klass.__name__, self.value.__name__), {"import %s" % module}
# Further error checking
if self.value.__name__ == '<lambda>':
raise ValueError("Cannot serialize function: lambda")
if self.value.__module__ is None:
raise ValueError("Cannot serialize function %r: No module" % self.value)
module_name = self.value.__module__
if '<' not in self.value.__qualname__: # Qualname can include <locals>
return '%s.%s' % (module_name, self.value.__qualname__), {'import %s' % self.value.__module__}
raise ValueError(
'Could not find function %s in %s.\n' % (self.value.__name__, module_name)
)
class FunctoolsPartialSerializer(BaseSerializer):
def serialize(self):
# Serialize functools.partial() arguments
func_string, func_imports = serializer_factory(self.value.func).serialize()
args_string, args_imports = serializer_factory(self.value.args).serialize()
keywords_string, keywords_imports = serializer_factory(self.value.keywords).serialize()
# Add any imports needed by arguments
imports = {'import functools', *func_imports, *args_imports, *keywords_imports}
return (
'functools.%s(%s, *%s, **%s)' % (
self.value.__class__.__name__,
func_string,
args_string,
keywords_string,
),
imports,
)
class IterableSerializer(BaseSerializer):
def serialize(self):
imports = set()
strings = []
for item in self.value:
item_string, item_imports = serializer_factory(item).serialize()
imports.update(item_imports)
strings.append(item_string)
# When len(strings)==0, the empty iterable should be serialized as
# "()", not "(,)" because (,) is invalid Python syntax.
value = "(%s)" if len(strings) != 1 else "(%s,)"
return value % (", ".join(strings)), imports
class ModelFieldSerializer(DeconstructableSerializer):
def serialize(self):
attr_name, path, args, kwargs = self.value.deconstruct()
return self.serialize_deconstructed(path, args, kwargs)
class ModelManagerSerializer(DeconstructableSerializer):
def serialize(self):
as_manager, manager_path, qs_path, args, kwargs = self.value.deconstruct()
if as_manager:
name, imports = self._serialize_path(qs_path)
return "%s.as_manager()" % name, imports
else:
return self.serialize_deconstructed(manager_path, args, kwargs)
class OperationSerializer(BaseSerializer):
def serialize(self):
from django.db.migrations.writer import OperationWriter
string, imports = OperationWriter(self.value, indentation=0).serialize()
# Nested operation, trailing comma is handled in upper OperationWriter._write()
return string.rstrip(','), imports
class RegexSerializer(BaseSerializer):
def serialize(self):
regex_pattern, pattern_imports = serializer_factory(self.value.pattern).serialize()
# Turn off default implicit flags (e.g. re.U) because regexes with the
# same implicit and explicit flags aren't equal.
flags = self.value.flags ^ re.compile('').flags
regex_flags, flag_imports = serializer_factory(flags).serialize()
imports = {'import re', *pattern_imports, *flag_imports}
args = [regex_pattern]
if flags:
args.append(regex_flags)
return "re.compile(%s)" % ', '.join(args), imports
class SequenceSerializer(BaseSequenceSerializer):
def _format(self):
return "[%s]"
class SetSerializer(BaseSequenceSerializer):
def _format(self):
# Serialize as a set literal except when value is empty because {}
# is an empty dict.
return '{%s}' if self.value else 'set(%s)'
class SettingsReferenceSerializer(BaseSerializer):
def serialize(self):
return "settings.%s" % self.value.setting_name, {"from django.conf import settings"}
class TimedeltaSerializer(BaseSerializer):
def serialize(self):
return repr(self.value), {"import datetime"}
class TimeSerializer(BaseSerializer):
def serialize(self):
value_repr = repr(self.value)
if isinstance(self.value, datetime_safe.time):
value_repr = "datetime.%s" % value_repr
return value_repr, {"import datetime"}
class TupleSerializer(BaseSequenceSerializer):
def _format(self):
# When len(value)==0, the empty tuple should be serialized as "()",
# not "(,)" because (,) is invalid Python syntax.
return "(%s)" if len(self.value) != 1 else "(%s,)"
class TypeSerializer(BaseSerializer):
def serialize(self):
special_cases = [
(models.Model, "models.Model", []),
]
for case, string, imports in special_cases:
if case is self.value:
return string, set(imports)
if hasattr(self.value, "__module__"):
module = self.value.__module__
if module == builtins.__name__:
return self.value.__name__, set()
else:
return "%s.%s" % (module, self.value.__name__), {"import %s" % module}
class UUIDSerializer(BaseSerializer):
def serialize(self):
return "uuid.%s" % repr(self.value), {"import uuid"}
def serializer_factory(value):
from django.db.migrations.writer import SettingsReference
if isinstance(value, Promise):
value = str(value)
elif isinstance(value, LazyObject):
# The unwrapped value is returned as the first item of the arguments
# tuple.
value = value.__reduce__()[1][0]
if isinstance(value, models.Field):
return ModelFieldSerializer(value)
if isinstance(value, models.manager.BaseManager):
return ModelManagerSerializer(value)
if isinstance(value, Operation):
return OperationSerializer(value)
if isinstance(value, type):
return TypeSerializer(value)
# Anything that knows how to deconstruct itself.
if hasattr(value, 'deconstruct'):
return DeconstructableSerializer(value)
# Unfortunately some of these are order-dependent.
if isinstance(value, frozenset):
return FrozensetSerializer(value)
if isinstance(value, list):
return SequenceSerializer(value)
if isinstance(value, set):
return SetSerializer(value)
if isinstance(value, tuple):
return TupleSerializer(value)
if isinstance(value, dict):
return DictionarySerializer(value)
if isinstance(value, enum.Enum):
return EnumSerializer(value)
if isinstance(value, datetime.datetime):
return DatetimeSerializer(value)
if isinstance(value, datetime.date):
return DateSerializer(value)
if isinstance(value, datetime.time):
return TimeSerializer(value)
if isinstance(value, datetime.timedelta):
return TimedeltaSerializer(value)
if isinstance(value, SettingsReference):
return SettingsReferenceSerializer(value)
if isinstance(value, float):
return FloatSerializer(value)
if isinstance(value, (bool, int, type(None), bytes, str)):
return BaseSimpleSerializer(value)
if isinstance(value, decimal.Decimal):
return DecimalSerializer(value)
if isinstance(value, (functools.partial, functools.partialmethod)):
return FunctoolsPartialSerializer(value)
if isinstance(value, (types.FunctionType, types.BuiltinFunctionType, types.MethodType)):
return FunctionTypeSerializer(value)
if isinstance(value, collections.abc.Iterable):
return IterableSerializer(value)
if isinstance(value, (COMPILED_REGEX_TYPE, RegexObject)):
return RegexSerializer(value)
if isinstance(value, uuid.UUID):
return UUIDSerializer(value)
raise ValueError(
"Cannot serialize: %r\nThere are some values Django cannot serialize into "
"migration files.\nFor more, see https://docs.djangoproject.com/en/%s/"
"topics/migrations/#migration-serializing" % (value, get_docs_version())
)
|
ec7a80c7171e11887d8949c980756f9eea8dee575f1a81dc8c36c667ee9d6473 | """
Classes to represent the definitions of aggregate functions.
"""
from django.core.exceptions import FieldError
from django.db.models.expressions import Case, Func, Star, When
from django.db.models.fields import DecimalField, FloatField, IntegerField
__all__ = [
'Aggregate', 'Avg', 'Count', 'Max', 'Min', 'StdDev', 'Sum', 'Variance',
]
class Aggregate(Func):
contains_aggregate = True
name = None
filter_template = '%s FILTER (WHERE %%(filter)s)'
window_compatible = True
def __init__(self, *args, filter=None, **kwargs):
self.filter = filter
super().__init__(*args, **kwargs)
def get_source_fields(self):
# Don't return the filter expression since it's not a source field.
return [e._output_field_or_none for e in super().get_source_expressions()]
def get_source_expressions(self):
source_expressions = super().get_source_expressions()
if self.filter:
source_expressions += [self.filter]
return source_expressions
def set_source_expressions(self, exprs):
self.filter = self.filter and exprs.pop()
return super().set_source_expressions(exprs)
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# Aggregates are not allowed in UPDATE queries, so ignore for_save
c = super().resolve_expression(query, allow_joins, reuse, summarize)
c.filter = c.filter and c.filter.resolve_expression(query, allow_joins, reuse, summarize)
if not summarize:
# Call Aggregate.get_source_expressions() to avoid
# returning self.filter and including that in this loop.
expressions = super(Aggregate, c).get_source_expressions()
for index, expr in enumerate(expressions):
if expr.contains_aggregate:
before_resolved = self.get_source_expressions()[index]
name = before_resolved.name if hasattr(before_resolved, 'name') else repr(before_resolved)
raise FieldError("Cannot compute %s('%s'): '%s' is an aggregate" % (c.name, name, name))
return c
@property
def default_alias(self):
expressions = self.get_source_expressions()
if len(expressions) == 1 and hasattr(expressions[0], 'name'):
return '%s__%s' % (expressions[0].name, self.name.lower())
raise TypeError("Complex expressions require an alias")
def get_group_by_cols(self):
return []
def as_sql(self, compiler, connection, **extra_context):
if self.filter:
if connection.features.supports_aggregate_filter_clause:
filter_sql, filter_params = self.filter.as_sql(compiler, connection)
template = self.filter_template % extra_context.get('template', self.template)
sql, params = super().as_sql(compiler, connection, template=template, filter=filter_sql)
return sql, params + filter_params
else:
copy = self.copy()
copy.filter = None
source_expressions = copy.get_source_expressions()
condition = When(self.filter, then=source_expressions[0])
copy.set_source_expressions([Case(condition)] + source_expressions[1:])
return super(Aggregate, copy).as_sql(compiler, connection, **extra_context)
return super().as_sql(compiler, connection, **extra_context)
def _get_repr_options(self):
options = super()._get_repr_options()
if self.filter:
options.update({'filter': self.filter})
return options
class Avg(Aggregate):
function = 'AVG'
name = 'Avg'
def _resolve_output_field(self):
source_field = self.get_source_fields()[0]
if isinstance(source_field, (IntegerField, DecimalField)):
return FloatField()
return super()._resolve_output_field()
def as_mysql(self, compiler, connection):
sql, params = super().as_sql(compiler, connection)
if self.output_field.get_internal_type() == 'DurationField':
sql = 'CAST(%s as SIGNED)' % sql
return sql, params
def as_oracle(self, compiler, connection):
if self.output_field.get_internal_type() == 'DurationField':
expression = self.get_source_expressions()[0]
from django.db.backends.oracle.functions import IntervalToSeconds, SecondsToInterval
return compiler.compile(
SecondsToInterval(Avg(IntervalToSeconds(expression), filter=self.filter))
)
return super().as_sql(compiler, connection)
class Count(Aggregate):
function = 'COUNT'
name = 'Count'
template = '%(function)s(%(distinct)s%(expressions)s)'
output_field = IntegerField()
def __init__(self, expression, distinct=False, filter=None, **extra):
if expression == '*':
expression = Star()
if isinstance(expression, Star) and filter is not None:
raise ValueError('Star cannot be used with filter. Please specify a field.')
super().__init__(
expression, distinct='DISTINCT ' if distinct else '',
filter=filter, **extra
)
def _get_repr_options(self):
return {**super()._get_repr_options(), 'distinct': self.extra['distinct'] != ''}
def convert_value(self, value, expression, connection):
return 0 if value is None else value
class Max(Aggregate):
function = 'MAX'
name = 'Max'
class Min(Aggregate):
function = 'MIN'
name = 'Min'
class StdDev(Aggregate):
name = 'StdDev'
output_field = FloatField()
def __init__(self, expression, sample=False, **extra):
self.function = 'STDDEV_SAMP' if sample else 'STDDEV_POP'
super().__init__(expression, **extra)
def _get_repr_options(self):
return {**super()._get_repr_options(), 'sample': self.function == 'STDDEV_SAMP'}
class Sum(Aggregate):
function = 'SUM'
name = 'Sum'
def as_mysql(self, compiler, connection):
sql, params = super().as_sql(compiler, connection)
if self.output_field.get_internal_type() == 'DurationField':
sql = 'CAST(%s as SIGNED)' % sql
return sql, params
def as_oracle(self, compiler, connection):
if self.output_field.get_internal_type() == 'DurationField':
expression = self.get_source_expressions()[0]
from django.db.backends.oracle.functions import IntervalToSeconds, SecondsToInterval
return compiler.compile(
SecondsToInterval(Sum(IntervalToSeconds(expression)))
)
return super().as_sql(compiler, connection)
class Variance(Aggregate):
name = 'Variance'
output_field = FloatField()
def __init__(self, expression, sample=False, **extra):
self.function = 'VAR_SAMP' if sample else 'VAR_POP'
super().__init__(expression, **extra)
def _get_repr_options(self):
return {**super()._get_repr_options(), 'sample': self.function == 'VAR_SAMP'}
|
1107ab1c514d452a1a54ac86f6e92c1507430ffcc9d9149d9400d0554b781a65 | import hashlib
from django.db.backends.utils import split_identifier
from django.utils.encoding import force_bytes
__all__ = ['Index']
class Index:
suffix = 'idx'
# The max length of the name of the index (restricted to 30 for
# cross-database compatibility with Oracle)
max_name_length = 30
def __init__(self, *, fields=(), name=None, db_tablespace=None):
if not isinstance(fields, (list, tuple)):
raise ValueError('Index.fields must be a list or tuple.')
if not fields:
raise ValueError('At least one field is required to define an index.')
self.fields = list(fields)
# A list of 2-tuple with the field name and ordering ('' or 'DESC').
self.fields_orders = [
(field_name[1:], 'DESC') if field_name.startswith('-') else (field_name, '')
for field_name in self.fields
]
self.name = name or ''
if self.name:
errors = self.check_name()
if len(self.name) > self.max_name_length:
errors.append('Index names cannot be longer than %s characters.' % self.max_name_length)
if errors:
raise ValueError(errors)
self.db_tablespace = db_tablespace
def check_name(self):
errors = []
# Name can't start with an underscore on Oracle; prepend D if needed.
if self.name[0] == '_':
errors.append('Index names cannot start with an underscore (_).')
self.name = 'D%s' % self.name[1:]
# Name can't start with a number on Oracle; prepend D if needed.
elif self.name[0].isdigit():
errors.append('Index names cannot start with a number (0-9).')
self.name = 'D%s' % self.name[1:]
return errors
def create_sql(self, model, schema_editor, using=''):
fields = [model._meta.get_field(field_name) for field_name, _ in self.fields_orders]
col_suffixes = [order[1] for order in self.fields_orders]
return schema_editor._create_index_sql(
model, fields, name=self.name, using=using, db_tablespace=self.db_tablespace,
col_suffixes=col_suffixes,
)
def remove_sql(self, model, schema_editor):
quote_name = schema_editor.quote_name
return schema_editor.sql_delete_index % {
'table': quote_name(model._meta.db_table),
'name': quote_name(self.name),
}
def deconstruct(self):
path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
path = path.replace('django.db.models.indexes', 'django.db.models')
kwargs = {'fields': self.fields, 'name': self.name}
if self.db_tablespace is not None:
kwargs['db_tablespace'] = self.db_tablespace
return (path, (), kwargs)
def clone(self):
"""Create a copy of this Index."""
_, _, kwargs = self.deconstruct()
return self.__class__(**kwargs)
@staticmethod
def _hash_generator(*args):
"""
Generate a 32-bit digest of a set of arguments that can be used to
shorten identifying names.
"""
h = hashlib.md5()
for arg in args:
h.update(force_bytes(arg))
return h.hexdigest()[:6]
def set_name_with_model(self, model):
"""
Generate a unique name for the index.
The name is divided into 3 parts - table name (12 chars), field name
(8 chars) and unique hash + suffix (10 chars). Each part is made to
fit its size by truncating the excess length.
"""
_, table_name = split_identifier(model._meta.db_table)
column_names = [model._meta.get_field(field_name).column for field_name, order in self.fields_orders]
column_names_with_order = [
(('-%s' if order else '%s') % column_name)
for column_name, (field_name, order) in zip(column_names, self.fields_orders)
]
# The length of the parts of the name is based on the default max
# length of 30 characters.
hash_data = [table_name] + column_names_with_order + [self.suffix]
self.name = '%s_%s_%s' % (
table_name[:11],
column_names[0][:7],
'%s_%s' % (self._hash_generator(*hash_data), self.suffix),
)
assert len(self.name) <= self.max_name_length, (
'Index too long for multiple database support. Is self.suffix '
'longer than 3 characters?'
)
self.check_name()
def __repr__(self):
return "<%s: fields='%s'>" % (self.__class__.__name__, ', '.join(self.fields))
def __eq__(self, other):
return (self.__class__ == other.__class__) and (self.deconstruct() == other.deconstruct())
|
fdd98af2eedfb4bd2e3584cae7c4f45b74826bd83c21c0d25aa6f0e30f8175be | """
The main QuerySet implementation. This provides the public API for the ORM.
"""
import copy
import operator
import warnings
from collections import OrderedDict, namedtuple
from functools import lru_cache
from itertools import chain
from django.conf import settings
from django.core import exceptions
from django.db import (
DJANGO_VERSION_PICKLE_KEY, IntegrityError, connections, router,
transaction,
)
from django.db.models import DateField, DateTimeField, sql
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import Collector
from django.db.models.expressions import F
from django.db.models.fields import AutoField
from django.db.models.functions import Trunc
from django.db.models.query_utils import FilteredRelation, InvalidQuery, Q
from django.db.models.sql.constants import CURSOR, GET_ITERATOR_CHUNK_SIZE
from django.utils import timezone
from django.utils.deprecation import RemovedInDjango30Warning
from django.utils.functional import cached_property, partition
from django.utils.version import get_version
# The maximum number of items to display in a QuerySet.__repr__
REPR_OUTPUT_SIZE = 20
# Pull into this namespace for backwards compatibility.
EmptyResultSet = sql.EmptyResultSet
class BaseIterable:
def __init__(self, queryset, chunked_fetch=False, chunk_size=GET_ITERATOR_CHUNK_SIZE):
self.queryset = queryset
self.chunked_fetch = chunked_fetch
self.chunk_size = chunk_size
class ModelIterable(BaseIterable):
"""Iterable that yields a model instance for each row."""
def __iter__(self):
queryset = self.queryset
db = queryset.db
compiler = queryset.query.get_compiler(using=db)
# Execute the query. This will also fill compiler.select, klass_info,
# and annotations.
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
select, klass_info, annotation_col_map = (compiler.select, compiler.klass_info,
compiler.annotation_col_map)
model_cls = klass_info['model']
select_fields = klass_info['select_fields']
model_fields_start, model_fields_end = select_fields[0], select_fields[-1] + 1
init_list = [f[0].target.attname
for f in select[model_fields_start:model_fields_end]]
related_populators = get_related_populators(klass_info, select, db)
for row in compiler.results_iter(results):
obj = model_cls.from_db(db, init_list, row[model_fields_start:model_fields_end])
for rel_populator in related_populators:
rel_populator.populate(row, obj)
if annotation_col_map:
for attr_name, col_pos in annotation_col_map.items():
setattr(obj, attr_name, row[col_pos])
# Add the known related objects to the model, if there are any
if queryset._known_related_objects:
for field, rel_objs in queryset._known_related_objects.items():
# Avoid overwriting objects loaded e.g. by select_related
if field.is_cached(obj):
continue
pk = getattr(obj, field.get_attname())
try:
rel_obj = rel_objs[pk]
except KeyError:
pass # may happen in qs1 | qs2 scenarios
else:
setattr(obj, field.name, rel_obj)
yield obj
class ValuesIterable(BaseIterable):
"""
Iterable returned by QuerySet.values() that yields a dict for each row.
"""
def __iter__(self):
queryset = self.queryset
query = queryset.query
compiler = query.get_compiler(queryset.db)
field_names = list(query.values_select)
extra_names = list(query.extra_select)
annotation_names = list(query.annotation_select)
# extra(select=...) cols are always at the start of the row.
names = extra_names + field_names + annotation_names
indexes = range(len(names))
for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size):
yield {names[i]: row[i] for i in indexes}
class ValuesListIterable(BaseIterable):
"""
Iterable returned by QuerySet.values_list(flat=False) that yields a tuple
for each row.
"""
def __iter__(self):
queryset = self.queryset
query = queryset.query
compiler = query.get_compiler(queryset.db)
if queryset._fields:
field_names = list(query.values_select)
extra_names = list(query.extra_select)
annotation_names = list(query.annotation_select)
# extra(select=...) cols are always at the start of the row.
names = extra_names + field_names + annotation_names
fields = list(queryset._fields) + [f for f in annotation_names if f not in queryset._fields]
if fields != names:
# Reorder according to fields.
index_map = {name: idx for idx, name in enumerate(names)}
rowfactory = operator.itemgetter(*[index_map[f] for f in fields])
return map(
rowfactory,
compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
)
return compiler.results_iter(tuple_expected=True, chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size)
class NamedValuesListIterable(ValuesListIterable):
"""
Iterable returned by QuerySet.values_list(named=True) that yields a
namedtuple for each row.
"""
@staticmethod
@lru_cache()
def create_namedtuple_class(*names):
# Cache namedtuple() with @lru_cache() since it's too slow to be
# called for every QuerySet evaluation.
return namedtuple('Row', names)
def __iter__(self):
queryset = self.queryset
if queryset._fields:
names = queryset._fields
else:
query = queryset.query
names = [*query.extra_select, *query.values_select, *query.annotation_select]
tuple_class = self.create_namedtuple_class(*names)
new = tuple.__new__
for row in super().__iter__():
yield new(tuple_class, row)
class FlatValuesListIterable(BaseIterable):
"""
Iterable returned by QuerySet.values_list(flat=True) that yields single
values.
"""
def __iter__(self):
queryset = self.queryset
compiler = queryset.query.get_compiler(queryset.db)
for row in compiler.results_iter(chunked_fetch=self.chunked_fetch, chunk_size=self.chunk_size):
yield row[0]
class QuerySet:
"""Represent a lazy database lookup for a set of objects."""
def __init__(self, model=None, query=None, using=None, hints=None):
self.model = model
self._db = using
self._hints = hints or {}
self.query = query or sql.Query(self.model)
self._result_cache = None
self._sticky_filter = False
self._for_write = False
self._prefetch_related_lookups = ()
self._prefetch_done = False
self._known_related_objects = {} # {rel_field: {pk: rel_obj}}
self._iterable_class = ModelIterable
self._fields = None
def as_manager(cls):
# Address the circular dependency between `Queryset` and `Manager`.
from django.db.models.manager import Manager
manager = Manager.from_queryset(cls)()
manager._built_with_as_manager = True
return manager
as_manager.queryset_only = True
as_manager = classmethod(as_manager)
########################
# PYTHON MAGIC METHODS #
########################
def __deepcopy__(self, memo):
"""Don't populate the QuerySet's cache."""
obj = self.__class__()
for k, v in self.__dict__.items():
if k == '_result_cache':
obj.__dict__[k] = None
else:
obj.__dict__[k] = copy.deepcopy(v, memo)
return obj
def __getstate__(self):
# Force the cache to be fully populated.
self._fetch_all()
return {**self.__dict__, DJANGO_VERSION_PICKLE_KEY: get_version()}
def __setstate__(self, state):
msg = None
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
current_version = get_version()
if current_version != pickled_version:
msg = (
"Pickled queryset instance's Django version %s does not "
"match the current version %s." % (pickled_version, current_version)
)
else:
msg = "Pickled queryset instance's Django version is not specified."
if msg:
warnings.warn(msg, RuntimeWarning, stacklevel=2)
self.__dict__.update(state)
def __repr__(self):
data = list(self[:REPR_OUTPUT_SIZE + 1])
if len(data) > REPR_OUTPUT_SIZE:
data[-1] = "...(remaining elements truncated)..."
return '<%s %r>' % (self.__class__.__name__, data)
def __len__(self):
self._fetch_all()
return len(self._result_cache)
def __iter__(self):
"""
The queryset iterator protocol uses three nested iterators in the
default case:
1. sql.compiler.execute_sql()
- Returns 100 rows at time (constants.GET_ITERATOR_CHUNK_SIZE)
using cursor.fetchmany(). This part is responsible for
doing some column masking, and returning the rows in chunks.
2. sql.compiler.results_iter()
- Returns one row at time. At this point the rows are still just
tuples. In some cases the return values are converted to
Python values at this location.
3. self.iterator()
- Responsible for turning the rows into model objects.
"""
self._fetch_all()
return iter(self._result_cache)
def __bool__(self):
self._fetch_all()
return bool(self._result_cache)
def __getitem__(self, k):
"""Retrieve an item or slice from the set of results."""
if not isinstance(k, (int, slice)):
raise TypeError
assert ((not isinstance(k, slice) and (k >= 0)) or
(isinstance(k, slice) and (k.start is None or k.start >= 0) and
(k.stop is None or k.stop >= 0))), \
"Negative indexing is not supported."
if self._result_cache is not None:
return self._result_cache[k]
if isinstance(k, slice):
qs = self._chain()
if k.start is not None:
start = int(k.start)
else:
start = None
if k.stop is not None:
stop = int(k.stop)
else:
stop = None
qs.query.set_limits(start, stop)
return list(qs)[::k.step] if k.step else qs
qs = self._chain()
qs.query.set_limits(k, k + 1)
qs._fetch_all()
return qs._result_cache[0]
def __and__(self, other):
self._merge_sanity_check(other)
if isinstance(other, EmptyQuerySet):
return other
if isinstance(self, EmptyQuerySet):
return self
combined = self._chain()
combined._merge_known_related_objects(other)
combined.query.combine(other.query, sql.AND)
return combined
def __or__(self, other):
self._merge_sanity_check(other)
if isinstance(self, EmptyQuerySet):
return other
if isinstance(other, EmptyQuerySet):
return self
combined = self._chain()
combined._merge_known_related_objects(other)
combined.query.combine(other.query, sql.OR)
return combined
####################################
# METHODS THAT DO DATABASE QUERIES #
####################################
def _iterator(self, use_chunked_fetch, chunk_size):
yield from self._iterable_class(self, chunked_fetch=use_chunked_fetch, chunk_size=chunk_size)
def iterator(self, chunk_size=2000):
"""
An iterator over the results from applying this QuerySet to the
database.
"""
if chunk_size <= 0:
raise ValueError('Chunk size must be strictly positive.')
use_chunked_fetch = not connections[self.db].settings_dict.get('DISABLE_SERVER_SIDE_CURSORS')
return self._iterator(use_chunked_fetch, chunk_size)
def aggregate(self, *args, **kwargs):
"""
Return a dictionary containing the calculations (aggregation)
over the current queryset.
If args is present the expression is passed as a kwarg using
the Aggregate object's default alias.
"""
if self.query.distinct_fields:
raise NotImplementedError("aggregate() + distinct(fields) not implemented.")
self._validate_values_are_expressions(args + tuple(kwargs.values()), method_name='aggregate')
for arg in args:
# The default_alias property raises TypeError if default_alias
# can't be set automatically or AttributeError if it isn't an
# attribute.
try:
arg.default_alias
except (AttributeError, TypeError):
raise TypeError("Complex aggregates require an alias")
kwargs[arg.default_alias] = arg
query = self.query.chain()
for (alias, aggregate_expr) in kwargs.items():
query.add_annotation(aggregate_expr, alias, is_summary=True)
if not query.annotations[alias].contains_aggregate:
raise TypeError("%s is not an aggregate expression" % alias)
return query.get_aggregation(self.db, kwargs)
def count(self):
"""
Perform a SELECT COUNT() and return the number of records as an
integer.
If the QuerySet is already fully cached, return the length of the
cached results set to avoid multiple SELECT COUNT(*) calls.
"""
if self._result_cache is not None:
return len(self._result_cache)
return self.query.get_count(using=self.db)
def get(self, *args, **kwargs):
"""
Perform the query and return a single object matching the given
keyword arguments.
"""
clone = self.filter(*args, **kwargs)
if self.query.can_filter() and not self.query.distinct_fields:
clone = clone.order_by()
num = len(clone)
if num == 1:
return clone._result_cache[0]
if not num:
raise self.model.DoesNotExist(
"%s matching query does not exist." %
self.model._meta.object_name
)
raise self.model.MultipleObjectsReturned(
"get() returned more than one %s -- it returned %s!" %
(self.model._meta.object_name, num)
)
def create(self, **kwargs):
"""
Create a new object with the given kwargs, saving it to the database
and returning the created object.
"""
obj = self.model(**kwargs)
self._for_write = True
obj.save(force_insert=True, using=self.db)
return obj
def _populate_pk_values(self, objs):
for obj in objs:
if obj.pk is None:
obj.pk = obj._meta.pk.get_pk_value_on_save(obj)
def bulk_create(self, objs, batch_size=None):
"""
Insert each of the instances into the database. Do *not* call
save() on each of the instances, do not send any pre/post_save
signals, and do not set the primary key attribute if it is an
autoincrement field (except if features.can_return_ids_from_bulk_insert=True).
Multi-table models are not supported.
"""
# When you bulk insert you don't get the primary keys back (if it's an
# autoincrement, except if can_return_ids_from_bulk_insert=True), so
# you can't insert into the child tables which references this. There
# are two workarounds:
# 1) This could be implemented if you didn't have an autoincrement pk
# 2) You could do it by doing O(n) normal inserts into the parent
# tables to get the primary keys back and then doing a single bulk
# insert into the childmost table.
# We currently set the primary keys on the objects when using
# PostgreSQL via the RETURNING ID clause. It should be possible for
# Oracle as well, but the semantics for extracting the primary keys is
# trickier so it's not done yet.
assert batch_size is None or batch_size > 0
# Check that the parents share the same concrete model with the our
# model to detect the inheritance pattern ConcreteGrandParent ->
# MultiTableParent -> ProxyChild. Simply checking self.model._meta.proxy
# would not identify that case as involving multiple tables.
for parent in self.model._meta.get_parent_list():
if parent._meta.concrete_model is not self.model._meta.concrete_model:
raise ValueError("Can't bulk create a multi-table inherited model")
if not objs:
return objs
self._for_write = True
connection = connections[self.db]
fields = self.model._meta.concrete_fields
objs = list(objs)
self._populate_pk_values(objs)
with transaction.atomic(using=self.db, savepoint=False):
objs_with_pk, objs_without_pk = partition(lambda o: o.pk is None, objs)
if objs_with_pk:
self._batched_insert(objs_with_pk, fields, batch_size)
for obj_with_pk in objs_with_pk:
obj_with_pk._state.adding = False
obj_with_pk._state.db = self.db
if objs_without_pk:
fields = [f for f in fields if not isinstance(f, AutoField)]
ids = self._batched_insert(objs_without_pk, fields, batch_size)
if connection.features.can_return_ids_from_bulk_insert:
assert len(ids) == len(objs_without_pk)
for obj_without_pk, pk in zip(objs_without_pk, ids):
obj_without_pk.pk = pk
obj_without_pk._state.adding = False
obj_without_pk._state.db = self.db
return objs
def get_or_create(self, defaults=None, **kwargs):
"""
Look up an object with the given kwargs, creating one if necessary.
Return a tuple of (object, created), where created is a boolean
specifying whether an object was created.
"""
lookup, params = self._extract_model_params(defaults, **kwargs)
# The get() needs to be targeted at the write database in order
# to avoid potential transaction consistency problems.
self._for_write = True
try:
return self.get(**lookup), False
except self.model.DoesNotExist:
return self._create_object_from_params(lookup, params)
def update_or_create(self, defaults=None, **kwargs):
"""
Look up an object with the given kwargs, updating one with defaults
if it exists, otherwise create a new one.
Return a tuple (object, created), where created is a boolean
specifying whether an object was created.
"""
defaults = defaults or {}
lookup, params = self._extract_model_params(defaults, **kwargs)
self._for_write = True
with transaction.atomic(using=self.db):
try:
obj = self.select_for_update().get(**lookup)
except self.model.DoesNotExist:
obj, created = self._create_object_from_params(lookup, params)
if created:
return obj, created
for k, v in defaults.items():
setattr(obj, k, v() if callable(v) else v)
obj.save(using=self.db)
return obj, False
def _create_object_from_params(self, lookup, params):
"""
Try to create an object using passed params. Used by get_or_create()
and update_or_create().
"""
try:
with transaction.atomic(using=self.db):
params = {k: v() if callable(v) else v for k, v in params.items()}
obj = self.create(**params)
return obj, True
except IntegrityError as e:
try:
return self.get(**lookup), False
except self.model.DoesNotExist:
pass
raise e
def _extract_model_params(self, defaults, **kwargs):
"""
Prepare `lookup` (kwargs that are valid model attributes), `params`
(for creating a model instance) based on given kwargs; for use by
get_or_create() and update_or_create().
"""
defaults = defaults or {}
lookup = kwargs.copy()
for f in self.model._meta.fields:
if f.attname in lookup:
lookup[f.name] = lookup.pop(f.attname)
params = {k: v for k, v in kwargs.items() if LOOKUP_SEP not in k}
params.update(defaults)
property_names = self.model._meta._property_names
invalid_params = []
for param in params:
try:
self.model._meta.get_field(param)
except exceptions.FieldDoesNotExist:
# It's okay to use a model's property if it has a setter.
if not (param in property_names and getattr(self.model, param).fset):
invalid_params.append(param)
if invalid_params:
raise exceptions.FieldError(
"Invalid field name(s) for model %s: '%s'." % (
self.model._meta.object_name,
"', '".join(sorted(invalid_params)),
))
return lookup, params
def _earliest_or_latest(self, *fields, field_name=None):
"""
Return the latest object, according to the model's
'get_latest_by' option or optional given field_name.
"""
if fields and field_name is not None:
raise ValueError('Cannot use both positional arguments and the field_name keyword argument.')
if field_name is not None:
warnings.warn(
'The field_name keyword argument to earliest() and latest() '
'is deprecated in favor of passing positional arguments.',
RemovedInDjango30Warning,
)
order_by = (field_name,)
elif fields:
order_by = fields
else:
order_by = getattr(self.model._meta, 'get_latest_by')
if order_by and not isinstance(order_by, (tuple, list)):
order_by = (order_by,)
if order_by is None:
raise ValueError(
"earliest() and latest() require either fields as positional "
"arguments or 'get_latest_by' in the model's Meta."
)
assert self.query.can_filter(), \
"Cannot change a query once a slice has been taken."
obj = self._chain()
obj.query.set_limits(high=1)
obj.query.clear_ordering(force_empty=True)
obj.query.add_ordering(*order_by)
return obj.get()
def earliest(self, *fields, field_name=None):
return self._earliest_or_latest(*fields, field_name=field_name)
def latest(self, *fields, field_name=None):
return self.reverse()._earliest_or_latest(*fields, field_name=field_name)
def first(self):
"""Return the first object of a query or None if no match is found."""
for obj in (self if self.ordered else self.order_by('pk'))[:1]:
return obj
def last(self):
"""Return the last object of a query or None if no match is found."""
for obj in (self.reverse() if self.ordered else self.order_by('-pk'))[:1]:
return obj
def in_bulk(self, id_list=None, *, field_name='pk'):
"""
Return a dictionary mapping each of the given IDs to the object with
that ID. If `id_list` isn't provided, evaluate the entire QuerySet.
"""
assert self.query.can_filter(), \
"Cannot use 'limit' or 'offset' with in_bulk"
if field_name != 'pk' and not self.model._meta.get_field(field_name).unique:
raise ValueError("in_bulk()'s field_name must be a unique field but %r isn't." % field_name)
if id_list is not None:
if not id_list:
return {}
filter_key = '{}__in'.format(field_name)
batch_size = connections[self.db].features.max_query_params
id_list = tuple(id_list)
# If the database has a limit on the number of query parameters
# (e.g. SQLite), retrieve objects in batches if necessary.
if batch_size and batch_size < len(id_list):
qs = ()
for offset in range(0, len(id_list), batch_size):
batch = id_list[offset:offset + batch_size]
qs += tuple(self.filter(**{filter_key: batch}).order_by())
else:
qs = self.filter(**{filter_key: id_list}).order_by()
else:
qs = self._chain()
return {getattr(obj, field_name): obj for obj in qs}
def delete(self):
"""Delete the records in the current QuerySet."""
assert self.query.can_filter(), \
"Cannot use 'limit' or 'offset' with delete."
if self._fields is not None:
raise TypeError("Cannot call delete() after .values() or .values_list()")
del_query = self._chain()
# The delete is actually 2 queries - one to find related objects,
# and one to delete. Make sure that the discovery of related
# objects is performed on the same database as the deletion.
del_query._for_write = True
# Disable non-supported fields.
del_query.query.select_for_update = False
del_query.query.select_related = False
del_query.query.clear_ordering(force_empty=True)
collector = Collector(using=del_query.db)
collector.collect(del_query)
deleted, _rows_count = collector.delete()
# Clear the result cache, in case this QuerySet gets reused.
self._result_cache = None
return deleted, _rows_count
delete.alters_data = True
delete.queryset_only = True
def _raw_delete(self, using):
"""
Delete objects found from the given queryset in single direct SQL
query. No signals are sent and there is no protection for cascades.
"""
return sql.DeleteQuery(self.model).delete_qs(self, using)
_raw_delete.alters_data = True
def update(self, **kwargs):
"""
Update all elements in the current QuerySet, setting all the given
fields to the appropriate values.
"""
assert self.query.can_filter(), \
"Cannot update a query once a slice has been taken."
self._for_write = True
query = self.query.chain(sql.UpdateQuery)
query.add_update_values(kwargs)
# Clear any annotations so that they won't be present in subqueries.
query._annotations = None
with transaction.atomic(using=self.db, savepoint=False):
rows = query.get_compiler(self.db).execute_sql(CURSOR)
self._result_cache = None
return rows
update.alters_data = True
def _update(self, values):
"""
A version of update() that accepts field objects instead of field names.
Used primarily for model saving and not intended for use by general
code (it requires too much poking around at model internals to be
useful at that level).
"""
assert self.query.can_filter(), \
"Cannot update a query once a slice has been taken."
query = self.query.chain(sql.UpdateQuery)
query.add_update_fields(values)
# Clear any annotations so that they won't be present in subqueries.
query._annotations = None
self._result_cache = None
return query.get_compiler(self.db).execute_sql(CURSOR)
_update.alters_data = True
_update.queryset_only = False
def exists(self):
if self._result_cache is None:
return self.query.has_results(using=self.db)
return bool(self._result_cache)
def _prefetch_related_objects(self):
# This method can only be called once the result cache has been filled.
prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
self._prefetch_done = True
def explain(self, *, format=None, **options):
return self.query.explain(using=self.db, format=format, **options)
##################################################
# PUBLIC METHODS THAT RETURN A QUERYSET SUBCLASS #
##################################################
def raw(self, raw_query, params=None, translations=None, using=None):
if using is None:
using = self.db
qs = RawQuerySet(raw_query, model=self.model, params=params, translations=translations, using=using)
qs._prefetch_related_lookups = self._prefetch_related_lookups[:]
return qs
def _values(self, *fields, **expressions):
clone = self._chain()
if expressions:
clone = clone.annotate(**expressions)
clone._fields = fields
clone.query.set_values(fields)
return clone
def values(self, *fields, **expressions):
fields += tuple(expressions)
clone = self._values(*fields, **expressions)
clone._iterable_class = ValuesIterable
return clone
def values_list(self, *fields, flat=False, named=False):
if flat and named:
raise TypeError("'flat' and 'named' can't be used together.")
if flat and len(fields) > 1:
raise TypeError("'flat' is not valid when values_list is called with more than one field.")
field_names = {f for f in fields if not hasattr(f, 'resolve_expression')}
_fields = []
expressions = {}
counter = 1
for field in fields:
if hasattr(field, 'resolve_expression'):
field_id_prefix = getattr(field, 'default_alias', field.__class__.__name__.lower())
while True:
field_id = field_id_prefix + str(counter)
counter += 1
if field_id not in field_names:
break
expressions[field_id] = field
_fields.append(field_id)
else:
_fields.append(field)
clone = self._values(*_fields, **expressions)
clone._iterable_class = (
NamedValuesListIterable if named
else FlatValuesListIterable if flat
else ValuesListIterable
)
return clone
def dates(self, field_name, kind, order='ASC'):
"""
Return a list of date objects representing all available dates for
the given field_name, scoped to 'kind'.
"""
assert kind in ('year', 'month', 'week', 'day'), \
"'kind' must be one of 'year', 'month', 'week', or 'day'."
assert order in ('ASC', 'DESC'), \
"'order' must be either 'ASC' or 'DESC'."
return self.annotate(
datefield=Trunc(field_name, kind, output_field=DateField()),
plain_field=F(field_name)
).values_list(
'datefield', flat=True
).distinct().filter(plain_field__isnull=False).order_by(('-' if order == 'DESC' else '') + 'datefield')
def datetimes(self, field_name, kind, order='ASC', tzinfo=None):
"""
Return a list of datetime objects representing all available
datetimes for the given field_name, scoped to 'kind'.
"""
assert kind in ('year', 'month', 'week', 'day', 'hour', 'minute', 'second'), \
"'kind' must be one of 'year', 'month', 'week', 'day', 'hour', 'minute', or 'second'."
assert order in ('ASC', 'DESC'), \
"'order' must be either 'ASC' or 'DESC'."
if settings.USE_TZ:
if tzinfo is None:
tzinfo = timezone.get_current_timezone()
else:
tzinfo = None
return self.annotate(
datetimefield=Trunc(field_name, kind, output_field=DateTimeField(), tzinfo=tzinfo),
plain_field=F(field_name)
).values_list(
'datetimefield', flat=True
).distinct().filter(plain_field__isnull=False).order_by(('-' if order == 'DESC' else '') + 'datetimefield')
def none(self):
"""Return an empty QuerySet."""
clone = self._chain()
clone.query.set_empty()
return clone
##################################################################
# PUBLIC METHODS THAT ALTER ATTRIBUTES AND RETURN A NEW QUERYSET #
##################################################################
def all(self):
"""
Return a new QuerySet that is a copy of the current one. This allows a
QuerySet to proxy for a model manager in some cases.
"""
return self._chain()
def filter(self, *args, **kwargs):
"""
Return a new QuerySet instance with the args ANDed to the existing
set.
"""
return self._filter_or_exclude(False, *args, **kwargs)
def exclude(self, *args, **kwargs):
"""
Return a new QuerySet instance with NOT (args) ANDed to the existing
set.
"""
return self._filter_or_exclude(True, *args, **kwargs)
def _filter_or_exclude(self, negate, *args, **kwargs):
if args or kwargs:
assert self.query.can_filter(), \
"Cannot filter a query once a slice has been taken."
clone = self._chain()
if negate:
clone.query.add_q(~Q(*args, **kwargs))
else:
clone.query.add_q(Q(*args, **kwargs))
return clone
def complex_filter(self, filter_obj):
"""
Return a new QuerySet instance with filter_obj added to the filters.
filter_obj can be a Q object or a dictionary of keyword lookup
arguments.
This exists to support framework features such as 'limit_choices_to',
and usually it will be more natural to use other methods.
"""
if isinstance(filter_obj, Q):
clone = self._chain()
clone.query.add_q(filter_obj)
return clone
else:
return self._filter_or_exclude(None, **filter_obj)
def _combinator_query(self, combinator, *other_qs, all=False):
# Clone the query to inherit the select list and everything
clone = self._chain()
# Clear limits and ordering so they can be reapplied
clone.query.clear_ordering(True)
clone.query.clear_limits()
clone.query.combined_queries = (self.query,) + tuple(qs.query for qs in other_qs)
clone.query.combinator = combinator
clone.query.combinator_all = all
return clone
def union(self, *other_qs, all=False):
# If the query is an EmptyQuerySet, combine all nonempty querysets.
if isinstance(self, EmptyQuerySet):
qs = [q for q in other_qs if not isinstance(q, EmptyQuerySet)]
return qs[0]._combinator_query('union', *qs[1:], all=all) if qs else self
return self._combinator_query('union', *other_qs, all=all)
def intersection(self, *other_qs):
# If any query is an EmptyQuerySet, return it.
if isinstance(self, EmptyQuerySet):
return self
for other in other_qs:
if isinstance(other, EmptyQuerySet):
return other
return self._combinator_query('intersection', *other_qs)
def difference(self, *other_qs):
# If the query is an EmptyQuerySet, return it.
if isinstance(self, EmptyQuerySet):
return self
return self._combinator_query('difference', *other_qs)
def select_for_update(self, nowait=False, skip_locked=False, of=()):
"""
Return a new QuerySet instance that will select objects with a
FOR UPDATE lock.
"""
if nowait and skip_locked:
raise ValueError('The nowait option cannot be used with skip_locked.')
obj = self._chain()
obj._for_write = True
obj.query.select_for_update = True
obj.query.select_for_update_nowait = nowait
obj.query.select_for_update_skip_locked = skip_locked
obj.query.select_for_update_of = of
return obj
def select_related(self, *fields):
"""
Return a new QuerySet instance that will select related objects.
If fields are specified, they must be ForeignKey fields and only those
related objects are included in the selection.
If select_related(None) is called, clear the list.
"""
if self._fields is not None:
raise TypeError("Cannot call select_related() after .values() or .values_list()")
obj = self._chain()
if fields == (None,):
obj.query.select_related = False
elif fields:
obj.query.add_select_related(fields)
else:
obj.query.select_related = True
return obj
def prefetch_related(self, *lookups):
"""
Return a new QuerySet instance that will prefetch the specified
Many-To-One and Many-To-Many related objects when the QuerySet is
evaluated.
When prefetch_related() is called more than once, append to the list of
prefetch lookups. If prefetch_related(None) is called, clear the list.
"""
clone = self._chain()
if lookups == (None,):
clone._prefetch_related_lookups = ()
else:
for lookup in lookups:
if isinstance(lookup, Prefetch):
lookup = lookup.prefetch_to
lookup = lookup.split(LOOKUP_SEP, 1)[0]
if lookup in self.query._filtered_relations:
raise ValueError('prefetch_related() is not supported with FilteredRelation.')
clone._prefetch_related_lookups = clone._prefetch_related_lookups + lookups
return clone
def annotate(self, *args, **kwargs):
"""
Return a query set in which the returned objects have been annotated
with extra data or aggregations.
"""
self._validate_values_are_expressions(args + tuple(kwargs.values()), method_name='annotate')
annotations = OrderedDict() # To preserve ordering of args
for arg in args:
# The default_alias property may raise a TypeError.
try:
if arg.default_alias in kwargs:
raise ValueError("The named annotation '%s' conflicts with the "
"default name for another annotation."
% arg.default_alias)
except TypeError:
raise TypeError("Complex annotations require an alias")
annotations[arg.default_alias] = arg
annotations.update(kwargs)
clone = self._chain()
names = self._fields
if names is None:
names = set(chain.from_iterable(
(field.name, field.attname) if hasattr(field, 'attname') else (field.name,)
for field in self.model._meta.get_fields()
))
for alias, annotation in annotations.items():
if alias in names:
raise ValueError("The annotation '%s' conflicts with a field on "
"the model." % alias)
if isinstance(annotation, FilteredRelation):
clone.query.add_filtered_relation(annotation, alias)
else:
clone.query.add_annotation(annotation, alias, is_summary=False)
for alias, annotation in clone.query.annotations.items():
if alias in annotations and annotation.contains_aggregate:
if clone._fields is None:
clone.query.group_by = True
else:
clone.query.set_group_by()
break
return clone
def order_by(self, *field_names):
"""Return a new QuerySet instance with the ordering changed."""
assert self.query.can_filter(), \
"Cannot reorder a query once a slice has been taken."
obj = self._chain()
obj.query.clear_ordering(force_empty=False)
obj.query.add_ordering(*field_names)
return obj
def distinct(self, *field_names):
"""
Return a new QuerySet instance that will select only distinct results.
"""
assert self.query.can_filter(), \
"Cannot create distinct fields once a slice has been taken."
obj = self._chain()
obj.query.add_distinct_fields(*field_names)
return obj
def extra(self, select=None, where=None, params=None, tables=None,
order_by=None, select_params=None):
"""Add extra SQL fragments to the query."""
assert self.query.can_filter(), \
"Cannot change a query once a slice has been taken"
clone = self._chain()
clone.query.add_extra(select, select_params, where, params, tables, order_by)
return clone
def reverse(self):
"""Reverse the ordering of the QuerySet."""
if not self.query.can_filter():
raise TypeError('Cannot reverse a query once a slice has been taken.')
clone = self._chain()
clone.query.standard_ordering = not clone.query.standard_ordering
return clone
def defer(self, *fields):
"""
Defer the loading of data for certain fields until they are accessed.
Add the set of deferred fields to any existing set of deferred fields.
The only exception to this is if None is passed in as the only
parameter, in which case removal all deferrals.
"""
if self._fields is not None:
raise TypeError("Cannot call defer() after .values() or .values_list()")
clone = self._chain()
if fields == (None,):
clone.query.clear_deferred_loading()
else:
clone.query.add_deferred_loading(fields)
return clone
def only(self, *fields):
"""
Essentially, the opposite of defer(). Only the fields passed into this
method and that are not already specified as deferred are loaded
immediately when the queryset is evaluated.
"""
if self._fields is not None:
raise TypeError("Cannot call only() after .values() or .values_list()")
if fields == (None,):
# Can only pass None to defer(), not only(), as the rest option.
# That won't stop people trying to do this, so let's be explicit.
raise TypeError("Cannot pass None as an argument to only().")
for field in fields:
field = field.split(LOOKUP_SEP, 1)[0]
if field in self.query._filtered_relations:
raise ValueError('only() is not supported with FilteredRelation.')
clone = self._chain()
clone.query.add_immediate_loading(fields)
return clone
def using(self, alias):
"""Select which database this QuerySet should execute against."""
clone = self._chain()
clone._db = alias
return clone
###################################
# PUBLIC INTROSPECTION ATTRIBUTES #
###################################
@property
def ordered(self):
"""
Return True if the QuerySet is ordered -- i.e. has an order_by()
clause or a default ordering on the model.
"""
if self.query.extra_order_by or self.query.order_by:
return True
elif self.query.default_ordering and self.query.get_meta().ordering:
return True
else:
return False
@property
def db(self):
"""Return the database used if this query is executed now."""
if self._for_write:
return self._db or router.db_for_write(self.model, **self._hints)
return self._db or router.db_for_read(self.model, **self._hints)
###################
# PRIVATE METHODS #
###################
def _insert(self, objs, fields, return_id=False, raw=False, using=None):
"""
Insert a new record for the given model. This provides an interface to
the InsertQuery class and is how Model.save() is implemented.
"""
self._for_write = True
if using is None:
using = self.db
query = sql.InsertQuery(self.model)
query.insert_values(fields, objs, raw=raw)
return query.get_compiler(using=using).execute_sql(return_id)
_insert.alters_data = True
_insert.queryset_only = False
def _batched_insert(self, objs, fields, batch_size):
"""
Helper method for bulk_create() to insert objs one batch at a time.
"""
ops = connections[self.db].ops
batch_size = (batch_size or max(ops.bulk_batch_size(fields, objs), 1))
inserted_ids = []
for item in [objs[i:i + batch_size] for i in range(0, len(objs), batch_size)]:
if connections[self.db].features.can_return_ids_from_bulk_insert:
inserted_id = self._insert(item, fields=fields, using=self.db, return_id=True)
if isinstance(inserted_id, list):
inserted_ids.extend(inserted_id)
else:
inserted_ids.append(inserted_id)
else:
self._insert(item, fields=fields, using=self.db)
return inserted_ids
def _chain(self, **kwargs):
"""
Return a copy of the current QuerySet that's ready for another
operation.
"""
obj = self._clone()
if obj._sticky_filter:
obj.query.filter_is_sticky = True
obj._sticky_filter = False
obj.__dict__.update(kwargs)
return obj
def _clone(self):
"""
Return a copy of the current QuerySet. A lightweight alternative
to deepcopy().
"""
c = self.__class__(model=self.model, query=self.query.chain(), using=self._db, hints=self._hints)
c._sticky_filter = self._sticky_filter
c._for_write = self._for_write
c._prefetch_related_lookups = self._prefetch_related_lookups[:]
c._known_related_objects = self._known_related_objects
c._iterable_class = self._iterable_class
c._fields = self._fields
return c
def _fetch_all(self):
if self._result_cache is None:
self._result_cache = list(self._iterable_class(self))
if self._prefetch_related_lookups and not self._prefetch_done:
self._prefetch_related_objects()
def _next_is_sticky(self):
"""
Indicate that the next filter call and the one following that should
be treated as a single filter. This is only important when it comes to
determining when to reuse tables for many-to-many filters. Required so
that we can filter naturally on the results of related managers.
This doesn't return a clone of the current QuerySet (it returns
"self"). The method is only used internally and should be immediately
followed by a filter() that does create a clone.
"""
self._sticky_filter = True
return self
def _merge_sanity_check(self, other):
"""Check that two QuerySet classes may be merged."""
if self._fields is not None and (
set(self.query.values_select) != set(other.query.values_select) or
set(self.query.extra_select) != set(other.query.extra_select) or
set(self.query.annotation_select) != set(other.query.annotation_select)):
raise TypeError(
"Merging '%s' classes must involve the same values in each case."
% self.__class__.__name__
)
def _merge_known_related_objects(self, other):
"""
Keep track of all known related objects from either QuerySet instance.
"""
for field, objects in other._known_related_objects.items():
self._known_related_objects.setdefault(field, {}).update(objects)
def resolve_expression(self, *args, **kwargs):
if self._fields and len(self._fields) > 1:
# values() queryset can only be used as nested queries
# if they are set up to select only a single field.
raise TypeError('Cannot use multi-field values as a filter value.')
query = self.query.resolve_expression(*args, **kwargs)
query._db = self._db
return query
resolve_expression.queryset_only = True
def _add_hints(self, **hints):
"""
Update hinting information for use by routers. Add new key/values or
overwrite existing key/values.
"""
self._hints.update(hints)
def _has_filters(self):
"""
Check if this QuerySet has any filtering going on. This isn't
equivalent with checking if all objects are present in results, for
example, qs[1:]._has_filters() -> False.
"""
return self.query.has_filters()
@staticmethod
def _validate_values_are_expressions(values, method_name):
invalid_args = sorted(str(arg) for arg in values if not hasattr(arg, 'resolve_expression'))
if invalid_args:
raise TypeError(
'QuerySet.%s() received non-expression(s): %s.' % (
method_name,
', '.join(invalid_args),
)
)
class InstanceCheckMeta(type):
def __instancecheck__(self, instance):
return isinstance(instance, QuerySet) and instance.query.is_empty()
class EmptyQuerySet(metaclass=InstanceCheckMeta):
"""
Marker class to checking if a queryset is empty by .none():
isinstance(qs.none(), EmptyQuerySet) -> True
"""
def __init__(self, *args, **kwargs):
raise TypeError("EmptyQuerySet can't be instantiated")
class RawQuerySet:
"""
Provide an iterator which converts the results of raw SQL queries into
annotated model instances.
"""
def __init__(self, raw_query, model=None, query=None, params=None,
translations=None, using=None, hints=None):
self.raw_query = raw_query
self.model = model
self._db = using
self._hints = hints or {}
self.query = query or sql.RawQuery(sql=raw_query, using=self.db, params=params)
self.params = params or ()
self.translations = translations or {}
self._result_cache = None
self._prefetch_related_lookups = ()
self._prefetch_done = False
def resolve_model_init_order(self):
"""Resolve the init field names and value positions."""
converter = connections[self.db].introspection.column_name_converter
model_init_fields = [f for f in self.model._meta.fields if converter(f.column) in self.columns]
annotation_fields = [(column, pos) for pos, column in enumerate(self.columns)
if column not in self.model_fields]
model_init_order = [self.columns.index(converter(f.column)) for f in model_init_fields]
model_init_names = [f.attname for f in model_init_fields]
return model_init_names, model_init_order, annotation_fields
def prefetch_related(self, *lookups):
"""Same as QuerySet.prefetch_related()"""
clone = self._clone()
if lookups == (None,):
clone._prefetch_related_lookups = ()
else:
clone._prefetch_related_lookups = clone._prefetch_related_lookups + lookups
return clone
def _prefetch_related_objects(self):
prefetch_related_objects(self._result_cache, *self._prefetch_related_lookups)
self._prefetch_done = True
def _clone(self):
"""Same as QuerySet._clone()"""
c = self.__class__(
self.raw_query, model=self.model, query=self.query, params=self.params,
translations=self.translations, using=self._db, hints=self._hints
)
c._prefetch_related_lookups = self._prefetch_related_lookups[:]
return c
def _fetch_all(self):
if self._result_cache is None:
self._result_cache = list(self.iterator())
if self._prefetch_related_lookups and not self._prefetch_done:
self._prefetch_related_objects()
def __len__(self):
self._fetch_all()
return len(self._result_cache)
def __bool__(self):
self._fetch_all()
return bool(self._result_cache)
def __iter__(self):
self._fetch_all()
return iter(self._result_cache)
def iterator(self):
# Cache some things for performance reasons outside the loop.
db = self.db
compiler = connections[db].ops.compiler('SQLCompiler')(
self.query, connections[db], db
)
query = iter(self.query)
try:
model_init_names, model_init_pos, annotation_fields = self.resolve_model_init_order()
if self.model._meta.pk.attname not in model_init_names:
raise InvalidQuery('Raw query must include the primary key')
model_cls = self.model
fields = [self.model_fields.get(c) for c in self.columns]
converters = compiler.get_converters([
f.get_col(f.model._meta.db_table) if f else None for f in fields
])
if converters:
query = compiler.apply_converters(query, converters)
for values in query:
# Associate fields to values
model_init_values = [values[pos] for pos in model_init_pos]
instance = model_cls.from_db(db, model_init_names, model_init_values)
if annotation_fields:
for column, pos in annotation_fields:
setattr(instance, column, values[pos])
yield instance
finally:
# Done iterating the Query. If it has its own cursor, close it.
if hasattr(self.query, 'cursor') and self.query.cursor:
self.query.cursor.close()
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self.query)
def __getitem__(self, k):
return list(self)[k]
@property
def db(self):
"""Return the database used if this query is executed now."""
return self._db or router.db_for_read(self.model, **self._hints)
def using(self, alias):
"""Select the database this RawQuerySet should execute against."""
return RawQuerySet(
self.raw_query, model=self.model,
query=self.query.chain(using=alias),
params=self.params, translations=self.translations,
using=alias,
)
@cached_property
def columns(self):
"""
A list of model field names in the order they'll appear in the
query results.
"""
columns = self.query.get_columns()
# Adjust any column names which don't match field names
for (query_name, model_name) in self.translations.items():
# Ignore translations for nonexistent column names
try:
index = columns.index(query_name)
except ValueError:
pass
else:
columns[index] = model_name
return columns
@cached_property
def model_fields(self):
"""A dict mapping column names to model field names."""
converter = connections[self.db].introspection.table_name_converter
model_fields = {}
for field in self.model._meta.fields:
name, column = field.get_attname_column()
model_fields[converter(column)] = field
return model_fields
class Prefetch:
def __init__(self, lookup, queryset=None, to_attr=None):
# `prefetch_through` is the path we traverse to perform the prefetch.
self.prefetch_through = lookup
# `prefetch_to` is the path to the attribute that stores the result.
self.prefetch_to = lookup
if queryset is not None and not issubclass(queryset._iterable_class, ModelIterable):
raise ValueError('Prefetch querysets cannot use values().')
if to_attr:
self.prefetch_to = LOOKUP_SEP.join(lookup.split(LOOKUP_SEP)[:-1] + [to_attr])
self.queryset = queryset
self.to_attr = to_attr
def __getstate__(self):
obj_dict = self.__dict__.copy()
if self.queryset is not None:
# Prevent the QuerySet from being evaluated
obj_dict['queryset'] = self.queryset._chain(
_result_cache=[],
_prefetch_done=True,
)
return obj_dict
def add_prefix(self, prefix):
self.prefetch_through = prefix + LOOKUP_SEP + self.prefetch_through
self.prefetch_to = prefix + LOOKUP_SEP + self.prefetch_to
def get_current_prefetch_to(self, level):
return LOOKUP_SEP.join(self.prefetch_to.split(LOOKUP_SEP)[:level + 1])
def get_current_to_attr(self, level):
parts = self.prefetch_to.split(LOOKUP_SEP)
to_attr = parts[level]
as_attr = self.to_attr and level == len(parts) - 1
return to_attr, as_attr
def get_current_queryset(self, level):
if self.get_current_prefetch_to(level) == self.prefetch_to:
return self.queryset
return None
def __eq__(self, other):
return isinstance(other, Prefetch) and self.prefetch_to == other.prefetch_to
def __hash__(self):
return hash((self.__class__, self.prefetch_to))
def normalize_prefetch_lookups(lookups, prefix=None):
"""Normalize lookups into Prefetch objects."""
ret = []
for lookup in lookups:
if not isinstance(lookup, Prefetch):
lookup = Prefetch(lookup)
if prefix:
lookup.add_prefix(prefix)
ret.append(lookup)
return ret
def prefetch_related_objects(model_instances, *related_lookups):
"""
Populate prefetched object caches for a list of model instances based on
the lookups/Prefetch instances given.
"""
if not model_instances:
return # nothing to do
# We need to be able to dynamically add to the list of prefetch_related
# lookups that we look up (see below). So we need some book keeping to
# ensure we don't do duplicate work.
done_queries = {} # dictionary of things like 'foo__bar': [results]
auto_lookups = set() # we add to this as we go through.
followed_descriptors = set() # recursion protection
all_lookups = normalize_prefetch_lookups(reversed(related_lookups))
while all_lookups:
lookup = all_lookups.pop()
if lookup.prefetch_to in done_queries:
if lookup.queryset:
raise ValueError("'%s' lookup was already seen with a different queryset. "
"You may need to adjust the ordering of your lookups." % lookup.prefetch_to)
continue
# Top level, the list of objects to decorate is the result cache
# from the primary QuerySet. It won't be for deeper levels.
obj_list = model_instances
through_attrs = lookup.prefetch_through.split(LOOKUP_SEP)
for level, through_attr in enumerate(through_attrs):
# Prepare main instances
if not obj_list:
break
prefetch_to = lookup.get_current_prefetch_to(level)
if prefetch_to in done_queries:
# Skip any prefetching, and any object preparation
obj_list = done_queries[prefetch_to]
continue
# Prepare objects:
good_objects = True
for obj in obj_list:
# Since prefetching can re-use instances, it is possible to have
# the same instance multiple times in obj_list, so obj might
# already be prepared.
if not hasattr(obj, '_prefetched_objects_cache'):
try:
obj._prefetched_objects_cache = {}
except (AttributeError, TypeError):
# Must be an immutable object from
# values_list(flat=True), for example (TypeError) or
# a QuerySet subclass that isn't returning Model
# instances (AttributeError), either in Django or a 3rd
# party. prefetch_related() doesn't make sense, so quit.
good_objects = False
break
if not good_objects:
break
# Descend down tree
# We assume that objects retrieved are homogeneous (which is the premise
# of prefetch_related), so what applies to first object applies to all.
first_obj = obj_list[0]
to_attr = lookup.get_current_to_attr(level)[0]
prefetcher, descriptor, attr_found, is_fetched = get_prefetcher(first_obj, through_attr, to_attr)
if not attr_found:
raise AttributeError("Cannot find '%s' on %s object, '%s' is an invalid "
"parameter to prefetch_related()" %
(through_attr, first_obj.__class__.__name__, lookup.prefetch_through))
if level == len(through_attrs) - 1 and prefetcher is None:
# Last one, this *must* resolve to something that supports
# prefetching, otherwise there is no point adding it and the
# developer asking for it has made a mistake.
raise ValueError("'%s' does not resolve to an item that supports "
"prefetching - this is an invalid parameter to "
"prefetch_related()." % lookup.prefetch_through)
if prefetcher is not None and not is_fetched:
obj_list, additional_lookups = prefetch_one_level(obj_list, prefetcher, lookup, level)
# We need to ensure we don't keep adding lookups from the
# same relationships to stop infinite recursion. So, if we
# are already on an automatically added lookup, don't add
# the new lookups from relationships we've seen already.
if not (prefetch_to in done_queries and lookup in auto_lookups and descriptor in followed_descriptors):
done_queries[prefetch_to] = obj_list
new_lookups = normalize_prefetch_lookups(reversed(additional_lookups), prefetch_to)
auto_lookups.update(new_lookups)
all_lookups.extend(new_lookups)
followed_descriptors.add(descriptor)
else:
# Either a singly related object that has already been fetched
# (e.g. via select_related), or hopefully some other property
# that doesn't support prefetching but needs to be traversed.
# We replace the current list of parent objects with the list
# of related objects, filtering out empty or missing values so
# that we can continue with nullable or reverse relations.
new_obj_list = []
for obj in obj_list:
if through_attr in getattr(obj, '_prefetched_objects_cache', ()):
# If related objects have been prefetched, use the
# cache rather than the object's through_attr.
new_obj = list(obj._prefetched_objects_cache.get(through_attr))
else:
try:
new_obj = getattr(obj, through_attr)
except exceptions.ObjectDoesNotExist:
continue
if new_obj is None:
continue
# We special-case `list` rather than something more generic
# like `Iterable` because we don't want to accidentally match
# user models that define __iter__.
if isinstance(new_obj, list):
new_obj_list.extend(new_obj)
else:
new_obj_list.append(new_obj)
obj_list = new_obj_list
def get_prefetcher(instance, through_attr, to_attr):
"""
For the attribute 'through_attr' on the given instance, find
an object that has a get_prefetch_queryset().
Return a 4 tuple containing:
(the object with get_prefetch_queryset (or None),
the descriptor object representing this relationship (or None),
a boolean that is False if the attribute was not found at all,
a boolean that is True if the attribute has already been fetched)
"""
prefetcher = None
is_fetched = False
# For singly related objects, we have to avoid getting the attribute
# from the object, as this will trigger the query. So we first try
# on the class, in order to get the descriptor object.
rel_obj_descriptor = getattr(instance.__class__, through_attr, None)
if rel_obj_descriptor is None:
attr_found = hasattr(instance, through_attr)
else:
attr_found = True
if rel_obj_descriptor:
# singly related object, descriptor object has the
# get_prefetch_queryset() method.
if hasattr(rel_obj_descriptor, 'get_prefetch_queryset'):
prefetcher = rel_obj_descriptor
if rel_obj_descriptor.is_cached(instance):
is_fetched = True
else:
# descriptor doesn't support prefetching, so we go ahead and get
# the attribute on the instance rather than the class to
# support many related managers
rel_obj = getattr(instance, through_attr)
if hasattr(rel_obj, 'get_prefetch_queryset'):
prefetcher = rel_obj
if through_attr != to_attr:
# Special case cached_property instances because hasattr
# triggers attribute computation and assignment.
if isinstance(getattr(instance.__class__, to_attr, None), cached_property):
is_fetched = to_attr in instance.__dict__
else:
is_fetched = hasattr(instance, to_attr)
else:
is_fetched = through_attr in instance._prefetched_objects_cache
return prefetcher, rel_obj_descriptor, attr_found, is_fetched
def prefetch_one_level(instances, prefetcher, lookup, level):
"""
Helper function for prefetch_related_objects().
Run prefetches on all instances using the prefetcher object,
assigning results to relevant caches in instance.
Return the prefetched objects along with any additional prefetches that
must be done due to prefetch_related lookups found from default managers.
"""
# prefetcher must have a method get_prefetch_queryset() which takes a list
# of instances, and returns a tuple:
# (queryset of instances of self.model that are related to passed in instances,
# callable that gets value to be matched for returned instances,
# callable that gets value to be matched for passed in instances,
# boolean that is True for singly related objects,
# cache or field name to assign to,
# boolean that is True when the previous argument is a cache name vs a field name).
# The 'values to be matched' must be hashable as they will be used
# in a dictionary.
rel_qs, rel_obj_attr, instance_attr, single, cache_name, is_descriptor = (
prefetcher.get_prefetch_queryset(instances, lookup.get_current_queryset(level)))
# We have to handle the possibility that the QuerySet we just got back
# contains some prefetch_related lookups. We don't want to trigger the
# prefetch_related functionality by evaluating the query. Rather, we need
# to merge in the prefetch_related lookups.
# Copy the lookups in case it is a Prefetch object which could be reused
# later (happens in nested prefetch_related).
additional_lookups = [
copy.copy(additional_lookup) for additional_lookup
in getattr(rel_qs, '_prefetch_related_lookups', ())
]
if additional_lookups:
# Don't need to clone because the manager should have given us a fresh
# instance, so we access an internal instead of using public interface
# for performance reasons.
rel_qs._prefetch_related_lookups = ()
all_related_objects = list(rel_qs)
rel_obj_cache = {}
for rel_obj in all_related_objects:
rel_attr_val = rel_obj_attr(rel_obj)
rel_obj_cache.setdefault(rel_attr_val, []).append(rel_obj)
to_attr, as_attr = lookup.get_current_to_attr(level)
# Make sure `to_attr` does not conflict with a field.
if as_attr and instances:
# We assume that objects retrieved are homogeneous (which is the premise
# of prefetch_related), so what applies to first object applies to all.
model = instances[0].__class__
try:
model._meta.get_field(to_attr)
except exceptions.FieldDoesNotExist:
pass
else:
msg = 'to_attr={} conflicts with a field on the {} model.'
raise ValueError(msg.format(to_attr, model.__name__))
# Whether or not we're prefetching the last part of the lookup.
leaf = len(lookup.prefetch_through.split(LOOKUP_SEP)) - 1 == level
for obj in instances:
instance_attr_val = instance_attr(obj)
vals = rel_obj_cache.get(instance_attr_val, [])
if single:
val = vals[0] if vals else None
if as_attr:
# A to_attr has been given for the prefetch.
setattr(obj, to_attr, val)
elif is_descriptor:
# cache_name points to a field name in obj.
# This field is a descriptor for a related object.
setattr(obj, cache_name, val)
else:
# No to_attr has been given for this prefetch operation and the
# cache_name does not point to a descriptor. Store the value of
# the field in the object's field cache.
obj._state.fields_cache[cache_name] = val
else:
if as_attr:
setattr(obj, to_attr, vals)
else:
manager = getattr(obj, to_attr)
if leaf and lookup.queryset is not None:
qs = manager._apply_rel_filters(lookup.queryset)
else:
qs = manager.get_queryset()
qs._result_cache = vals
# We don't want the individual qs doing prefetch_related now,
# since we have merged this into the current work.
qs._prefetch_done = True
obj._prefetched_objects_cache[cache_name] = qs
return all_related_objects, additional_lookups
class RelatedPopulator:
"""
RelatedPopulator is used for select_related() object instantiation.
The idea is that each select_related() model will be populated by a
different RelatedPopulator instance. The RelatedPopulator instances get
klass_info and select (computed in SQLCompiler) plus the used db as
input for initialization. That data is used to compute which columns
to use, how to instantiate the model, and how to populate the links
between the objects.
The actual creation of the objects is done in populate() method. This
method gets row and from_obj as input and populates the select_related()
model instance.
"""
def __init__(self, klass_info, select, db):
self.db = db
# Pre-compute needed attributes. The attributes are:
# - model_cls: the possibly deferred model class to instantiate
# - either:
# - cols_start, cols_end: usually the columns in the row are
# in the same order model_cls.__init__ expects them, so we
# can instantiate by model_cls(*row[cols_start:cols_end])
# - reorder_for_init: When select_related descends to a child
# class, then we want to reuse the already selected parent
# data. However, in this case the parent data isn't necessarily
# in the same order that Model.__init__ expects it to be, so
# we have to reorder the parent data. The reorder_for_init
# attribute contains a function used to reorder the field data
# in the order __init__ expects it.
# - pk_idx: the index of the primary key field in the reordered
# model data. Used to check if a related object exists at all.
# - init_list: the field attnames fetched from the database. For
# deferred models this isn't the same as all attnames of the
# model's fields.
# - related_populators: a list of RelatedPopulator instances if
# select_related() descends to related models from this model.
# - local_setter, remote_setter: Methods to set cached values on
# the object being populated and on the remote object. Usually
# these are Field.set_cached_value() methods.
select_fields = klass_info['select_fields']
from_parent = klass_info['from_parent']
if not from_parent:
self.cols_start = select_fields[0]
self.cols_end = select_fields[-1] + 1
self.init_list = [
f[0].target.attname for f in select[self.cols_start:self.cols_end]
]
self.reorder_for_init = None
else:
attname_indexes = {select[idx][0].target.attname: idx for idx in select_fields}
model_init_attnames = (f.attname for f in klass_info['model']._meta.concrete_fields)
self.init_list = [attname for attname in model_init_attnames if attname in attname_indexes]
self.reorder_for_init = operator.itemgetter(*[attname_indexes[attname] for attname in self.init_list])
self.model_cls = klass_info['model']
self.pk_idx = self.init_list.index(self.model_cls._meta.pk.attname)
self.related_populators = get_related_populators(klass_info, select, self.db)
self.local_setter = klass_info['local_setter']
self.remote_setter = klass_info['remote_setter']
def populate(self, row, from_obj):
if self.reorder_for_init:
obj_data = self.reorder_for_init(row)
else:
obj_data = row[self.cols_start:self.cols_end]
if obj_data[self.pk_idx] is None:
obj = None
else:
obj = self.model_cls.from_db(self.db, self.init_list, obj_data)
for rel_iter in self.related_populators:
rel_iter.populate(row, obj)
self.local_setter(from_obj, obj)
if obj is not None:
self.remote_setter(obj, from_obj)
def get_related_populators(klass_info, select, db):
iterators = []
related_klass_infos = klass_info.get('related_klass_infos', [])
for rel_klass_info in related_klass_infos:
rel_cls = RelatedPopulator(rel_klass_info, select, db)
iterators.append(rel_cls)
return iterators
|
10186fa0e20b4ea3e8fb0817084ac119b684bd3040bdc628349d6425005ad4dd | from django.core.exceptions import ObjectDoesNotExist
from django.db.models import signals
from django.db.models.aggregates import * # NOQA
from django.db.models.aggregates import __all__ as aggregates_all
from django.db.models.deletion import (
CASCADE, DO_NOTHING, PROTECT, SET, SET_DEFAULT, SET_NULL, ProtectedError,
)
from django.db.models.expressions import (
Case, Exists, Expression, ExpressionList, ExpressionWrapper, F, Func,
OuterRef, RowRange, Subquery, Value, ValueRange, When, Window, WindowFrame,
)
from django.db.models.fields import * # NOQA
from django.db.models.fields import __all__ as fields_all
from django.db.models.fields.files import FileField, ImageField
from django.db.models.fields.proxy import OrderWrt
from django.db.models.indexes import * # NOQA
from django.db.models.indexes import __all__ as indexes_all
from django.db.models.lookups import Lookup, Transform
from django.db.models.manager import Manager
from django.db.models.query import (
Prefetch, Q, QuerySet, prefetch_related_objects,
)
from django.db.models.query_utils import FilteredRelation
# Imports that would create circular imports if sorted
from django.db.models.base import DEFERRED, Model # isort:skip
from django.db.models.fields.related import ( # isort:skip
ForeignKey, ForeignObject, OneToOneField, ManyToManyField,
ManyToOneRel, ManyToManyRel, OneToOneRel,
)
__all__ = aggregates_all + fields_all + indexes_all
__all__ += [
'ObjectDoesNotExist', 'signals',
'CASCADE', 'DO_NOTHING', 'PROTECT', 'SET', 'SET_DEFAULT', 'SET_NULL',
'ProtectedError',
'Case', 'Exists', 'Expression', 'ExpressionList', 'ExpressionWrapper', 'F',
'Func', 'OuterRef', 'RowRange', 'Subquery', 'Value', 'ValueRange', 'When',
'Window', 'WindowFrame',
'FileField', 'ImageField', 'OrderWrt', 'Lookup', 'Transform', 'Manager',
'Prefetch', 'Q', 'QuerySet', 'prefetch_related_objects', 'DEFERRED', 'Model',
'FilteredRelation',
'ForeignKey', 'ForeignObject', 'OneToOneField', 'ManyToManyField',
'ManyToOneRel', 'ManyToManyRel', 'OneToOneRel',
]
|
261a63592f3362ec2f81df6b5e1ddf726f4de51334688e3c1d90680593287d09 | import copy
import inspect
from bisect import bisect
from collections import OrderedDict, defaultdict
from django.apps import apps
from django.conf import settings
from django.core.exceptions import FieldDoesNotExist, ImproperlyConfigured
from django.db import connections
from django.db.models import Manager
from django.db.models.fields import AutoField
from django.db.models.fields.proxy import OrderWrt
from django.db.models.query_utils import PathInfo
from django.utils.datastructures import ImmutableList, OrderedSet
from django.utils.functional import cached_property
from django.utils.text import camel_case_to_spaces, format_lazy
from django.utils.translation import override
PROXY_PARENTS = object()
EMPTY_RELATION_TREE = ()
IMMUTABLE_WARNING = (
"The return type of '%s' should never be mutated. If you want to manipulate this list "
"for your own use, make a copy first."
)
DEFAULT_NAMES = (
'verbose_name', 'verbose_name_plural', 'db_table', 'ordering',
'unique_together', 'permissions', 'get_latest_by', 'order_with_respect_to',
'app_label', 'db_tablespace', 'abstract', 'managed', 'proxy', 'swappable',
'auto_created', 'index_together', 'apps', 'default_permissions',
'select_on_save', 'default_related_name', 'required_db_features',
'required_db_vendor', 'base_manager_name', 'default_manager_name',
'indexes',
# For backwards compatibility with Django 1.11. RemovedInDjango30Warning
'manager_inheritance_from_future',
)
def normalize_together(option_together):
"""
option_together can be either a tuple of tuples, or a single
tuple of two strings. Normalize it to a tuple of tuples, so that
calling code can uniformly expect that.
"""
try:
if not option_together:
return ()
if not isinstance(option_together, (tuple, list)):
raise TypeError
first_element = option_together[0]
if not isinstance(first_element, (tuple, list)):
option_together = (option_together,)
# Normalize everything to tuples
return tuple(tuple(ot) for ot in option_together)
except TypeError:
# If the value of option_together isn't valid, return it
# verbatim; this will be picked up by the check framework later.
return option_together
def make_immutable_fields_list(name, data):
return ImmutableList(data, warning=IMMUTABLE_WARNING % name)
class Options:
FORWARD_PROPERTIES = {
'fields', 'many_to_many', 'concrete_fields', 'local_concrete_fields',
'_forward_fields_map', 'managers', 'managers_map', 'base_manager',
'default_manager',
}
REVERSE_PROPERTIES = {'related_objects', 'fields_map', '_relation_tree'}
default_apps = apps
def __init__(self, meta, app_label=None):
self._get_fields_cache = {}
self.local_fields = []
self.local_many_to_many = []
self.private_fields = []
self.local_managers = []
self.base_manager_name = None
self.default_manager_name = None
self.model_name = None
self.verbose_name = None
self.verbose_name_plural = None
self.db_table = ''
self.ordering = []
self._ordering_clash = False
self.indexes = []
self.unique_together = []
self.index_together = []
self.select_on_save = False
self.default_permissions = ('add', 'change', 'delete', 'view')
self.permissions = []
self.object_name = None
self.app_label = app_label
self.get_latest_by = None
self.order_with_respect_to = None
self.db_tablespace = settings.DEFAULT_TABLESPACE
self.required_db_features = []
self.required_db_vendor = None
self.meta = meta
self.pk = None
self.auto_field = None
self.abstract = False
self.managed = True
self.proxy = False
# For any class that is a proxy (including automatically created
# classes for deferred object loading), proxy_for_model tells us
# which class this model is proxying. Note that proxy_for_model
# can create a chain of proxy models. For non-proxy models, the
# variable is always None.
self.proxy_for_model = None
# For any non-abstract class, the concrete class is the model
# in the end of the proxy_for_model chain. In particular, for
# concrete models, the concrete_model is always the class itself.
self.concrete_model = None
self.swappable = None
self.parents = OrderedDict()
self.auto_created = False
# List of all lookups defined in ForeignKey 'limit_choices_to' options
# from *other* models. Needed for some admin checks. Internal use only.
self.related_fkey_lookups = []
# A custom app registry to use, if you're making a separate model set.
self.apps = self.default_apps
self.default_related_name = None
@property
def label(self):
return '%s.%s' % (self.app_label, self.object_name)
@property
def label_lower(self):
return '%s.%s' % (self.app_label, self.model_name)
@property
def app_config(self):
# Don't go through get_app_config to avoid triggering imports.
return self.apps.app_configs.get(self.app_label)
@property
def installed(self):
return self.app_config is not None
def contribute_to_class(self, cls, name):
from django.db import connection
from django.db.backends.utils import truncate_name
cls._meta = self
self.model = cls
# First, construct the default values for these options.
self.object_name = cls.__name__
self.model_name = self.object_name.lower()
self.verbose_name = camel_case_to_spaces(self.object_name)
# Store the original user-defined values for each option,
# for use when serializing the model definition
self.original_attrs = {}
# Next, apply any overridden values from 'class Meta'.
if self.meta:
meta_attrs = self.meta.__dict__.copy()
for name in self.meta.__dict__:
# Ignore any private attributes that Django doesn't care about.
# NOTE: We can't modify a dictionary's contents while looping
# over it, so we loop over the *original* dictionary instead.
if name.startswith('_'):
del meta_attrs[name]
for attr_name in DEFAULT_NAMES:
if attr_name in meta_attrs:
setattr(self, attr_name, meta_attrs.pop(attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
elif hasattr(self.meta, attr_name):
setattr(self, attr_name, getattr(self.meta, attr_name))
self.original_attrs[attr_name] = getattr(self, attr_name)
self.unique_together = normalize_together(self.unique_together)
self.index_together = normalize_together(self.index_together)
# verbose_name_plural is a special case because it uses a 's'
# by default.
if self.verbose_name_plural is None:
self.verbose_name_plural = format_lazy('{}s', self.verbose_name)
# order_with_respect_and ordering are mutually exclusive.
self._ordering_clash = bool(self.ordering and self.order_with_respect_to)
# Any leftover attributes must be invalid.
if meta_attrs != {}:
raise TypeError("'class Meta' got invalid attribute(s): %s" % ','.join(meta_attrs))
else:
self.verbose_name_plural = format_lazy('{}s', self.verbose_name)
del self.meta
# If the db_table wasn't provided, use the app_label + model_name.
if not self.db_table:
self.db_table = "%s_%s" % (self.app_label, self.model_name)
self.db_table = truncate_name(self.db_table, connection.ops.max_name_length())
def _prepare(self, model):
if self.order_with_respect_to:
# The app registry will not be ready at this point, so we cannot
# use get_field().
query = self.order_with_respect_to
try:
self.order_with_respect_to = next(
f for f in self._get_fields(reverse=False)
if f.name == query or f.attname == query
)
except StopIteration:
raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, query))
self.ordering = ('_order',)
if not any(isinstance(field, OrderWrt) for field in model._meta.local_fields):
model.add_to_class('_order', OrderWrt())
else:
self.order_with_respect_to = None
if self.pk is None:
if self.parents:
# Promote the first parent link in lieu of adding yet another
# field.
field = next(iter(self.parents.values()))
# Look for a local field with the same name as the
# first parent link. If a local field has already been
# created, use it instead of promoting the parent
already_created = [fld for fld in self.local_fields if fld.name == field.name]
if already_created:
field = already_created[0]
field.primary_key = True
self.setup_pk(field)
if not field.remote_field.parent_link:
raise ImproperlyConfigured(
'Add parent_link=True to %s.' % field,
)
else:
auto = AutoField(verbose_name='ID', primary_key=True, auto_created=True)
model.add_to_class('id', auto)
def add_manager(self, manager):
self.local_managers.append(manager)
self._expire_cache()
def add_field(self, field, private=False):
# Insert the given field in the order in which it was created, using
# the "creation_counter" attribute of the field.
# Move many-to-many related fields from self.fields into
# self.many_to_many.
if private:
self.private_fields.append(field)
elif field.is_relation and field.many_to_many:
self.local_many_to_many.insert(bisect(self.local_many_to_many, field), field)
else:
self.local_fields.insert(bisect(self.local_fields, field), field)
self.setup_pk(field)
# If the field being added is a relation to another known field,
# expire the cache on this field and the forward cache on the field
# being referenced, because there will be new relationships in the
# cache. Otherwise, expire the cache of references *to* this field.
# The mechanism for getting at the related model is slightly odd -
# ideally, we'd just ask for field.related_model. However, related_model
# is a cached property, and all the models haven't been loaded yet, so
# we need to make sure we don't cache a string reference.
if field.is_relation and hasattr(field.remote_field, 'model') and field.remote_field.model:
try:
field.remote_field.model._meta._expire_cache(forward=False)
except AttributeError:
pass
self._expire_cache()
else:
self._expire_cache(reverse=False)
def setup_pk(self, field):
if not self.pk and field.primary_key:
self.pk = field
field.serialize = False
def setup_proxy(self, target):
"""
Do the internal setup so that the current model is a proxy for
"target".
"""
self.pk = target._meta.pk
self.proxy_for_model = target
self.db_table = target._meta.db_table
def __repr__(self):
return '<Options for %s>' % self.object_name
def __str__(self):
return "%s.%s" % (self.app_label, self.model_name)
def can_migrate(self, connection):
"""
Return True if the model can/should be migrated on the `connection`.
`connection` can be either a real connection or a connection alias.
"""
if self.proxy or self.swapped or not self.managed:
return False
if isinstance(connection, str):
connection = connections[connection]
if self.required_db_vendor:
return self.required_db_vendor == connection.vendor
if self.required_db_features:
return all(getattr(connection.features, feat, False)
for feat in self.required_db_features)
return True
@property
def verbose_name_raw(self):
"""Return the untranslated verbose name."""
with override(None):
return str(self.verbose_name)
@property
def swapped(self):
"""
Has this model been swapped out for another? If so, return the model
name of the replacement; otherwise, return None.
For historical reasons, model name lookups using get_model() are
case insensitive, so we make sure we are case insensitive here.
"""
if self.swappable:
swapped_for = getattr(settings, self.swappable, None)
if swapped_for:
try:
swapped_label, swapped_object = swapped_for.split('.')
except ValueError:
# setting not in the format app_label.model_name
# raising ImproperlyConfigured here causes problems with
# test cleanup code - instead it is raised in get_user_model
# or as part of validation.
return swapped_for
if '%s.%s' % (swapped_label, swapped_object.lower()) != self.label_lower:
return swapped_for
return None
@cached_property
def managers(self):
managers = []
seen_managers = set()
bases = (b for b in self.model.mro() if hasattr(b, '_meta'))
for depth, base in enumerate(bases):
for manager in base._meta.local_managers:
if manager.name in seen_managers:
continue
manager = copy.copy(manager)
manager.model = self.model
seen_managers.add(manager.name)
managers.append((depth, manager.creation_counter, manager))
return make_immutable_fields_list(
"managers",
(m[2] for m in sorted(managers)),
)
@cached_property
def managers_map(self):
return {manager.name: manager for manager in self.managers}
@cached_property
def base_manager(self):
base_manager_name = self.base_manager_name
if not base_manager_name:
# Get the first parent's base_manager_name if there's one.
for parent in self.model.mro()[1:]:
if hasattr(parent, '_meta'):
if parent._base_manager.name != '_base_manager':
base_manager_name = parent._base_manager.name
break
if base_manager_name:
try:
return self.managers_map[base_manager_name]
except KeyError:
raise ValueError(
"%s has no manager named %r" % (
self.object_name,
base_manager_name,
)
)
manager = Manager()
manager.name = '_base_manager'
manager.model = self.model
manager.auto_created = True
return manager
@cached_property
def default_manager(self):
default_manager_name = self.default_manager_name
if not default_manager_name and not self.local_managers:
# Get the first parent's default_manager_name if there's one.
for parent in self.model.mro()[1:]:
if hasattr(parent, '_meta'):
default_manager_name = parent._meta.default_manager_name
break
if default_manager_name:
try:
return self.managers_map[default_manager_name]
except KeyError:
raise ValueError(
"%s has no manager named %r" % (
self.object_name,
default_manager_name,
)
)
if self.managers:
return self.managers[0]
@cached_property
def fields(self):
"""
Return a list of all forward fields on the model and its parents,
excluding ManyToManyFields.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
# For legacy reasons, the fields property should only contain forward
# fields that are not private or with a m2m cardinality. Therefore we
# pass these three filters as filters to the generator.
# The third lambda is a longwinded way of checking f.related_model - we don't
# use that property directly because related_model is a cached property,
# and all the models may not have been loaded yet; we don't want to cache
# the string reference to the related_model.
def is_not_an_m2m_field(f):
return not (f.is_relation and f.many_to_many)
def is_not_a_generic_relation(f):
return not (f.is_relation and f.one_to_many)
def is_not_a_generic_foreign_key(f):
return not (
f.is_relation and f.many_to_one and not (hasattr(f.remote_field, 'model') and f.remote_field.model)
)
return make_immutable_fields_list(
"fields",
(f for f in self._get_fields(reverse=False)
if is_not_an_m2m_field(f) and is_not_a_generic_relation(f) and is_not_a_generic_foreign_key(f))
)
@cached_property
def concrete_fields(self):
"""
Return a list of all concrete fields on the model and its parents.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
return make_immutable_fields_list(
"concrete_fields", (f for f in self.fields if f.concrete)
)
@cached_property
def local_concrete_fields(self):
"""
Return a list of all concrete fields on the model.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
return make_immutable_fields_list(
"local_concrete_fields", (f for f in self.local_fields if f.concrete)
)
@cached_property
def many_to_many(self):
"""
Return a list of all many to many fields on the model and its parents.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this list.
"""
return make_immutable_fields_list(
"many_to_many",
(f for f in self._get_fields(reverse=False) if f.is_relation and f.many_to_many)
)
@cached_property
def related_objects(self):
"""
Return all related objects pointing to the current model. The related
objects can come from a one-to-one, one-to-many, or many-to-many field
relation type.
Private API intended only to be used by Django itself; get_fields()
combined with filtering of field properties is the public API for
obtaining this field list.
"""
all_related_fields = self._get_fields(forward=False, reverse=True, include_hidden=True)
return make_immutable_fields_list(
"related_objects",
(obj for obj in all_related_fields if not obj.hidden or obj.field.many_to_many)
)
@cached_property
def _forward_fields_map(self):
res = {}
fields = self._get_fields(reverse=False)
for field in fields:
res[field.name] = field
# Due to the way Django's internals work, get_field() should also
# be able to fetch a field by attname. In the case of a concrete
# field with relation, includes the *_id name too
try:
res[field.attname] = field
except AttributeError:
pass
return res
@cached_property
def fields_map(self):
res = {}
fields = self._get_fields(forward=False, include_hidden=True)
for field in fields:
res[field.name] = field
# Due to the way Django's internals work, get_field() should also
# be able to fetch a field by attname. In the case of a concrete
# field with relation, includes the *_id name too
try:
res[field.attname] = field
except AttributeError:
pass
return res
def get_field(self, field_name):
"""
Return a field instance given the name of a forward or reverse field.
"""
try:
# In order to avoid premature loading of the relation tree
# (expensive) we prefer checking if the field is a forward field.
return self._forward_fields_map[field_name]
except KeyError:
# If the app registry is not ready, reverse fields are
# unavailable, therefore we throw a FieldDoesNotExist exception.
if not self.apps.models_ready:
raise FieldDoesNotExist(
"%s has no field named '%s'. The app cache isn't ready yet, "
"so if this is an auto-created related field, it won't "
"be available yet." % (self.object_name, field_name)
)
try:
# Retrieve field instance by name from cached or just-computed
# field map.
return self.fields_map[field_name]
except KeyError:
raise FieldDoesNotExist("%s has no field named '%s'" % (self.object_name, field_name))
def get_base_chain(self, model):
"""
Return a list of parent classes leading to `model` (ordered from
closest to most distant ancestor). This has to handle the case where
`model` is a grandparent or even more distant relation.
"""
if not self.parents:
return []
if model in self.parents:
return [model]
for parent in self.parents:
res = parent._meta.get_base_chain(model)
if res:
res.insert(0, parent)
return res
return []
def get_parent_list(self):
"""
Return all the ancestors of this model as a list ordered by MRO.
Useful for determining if something is an ancestor, regardless of lineage.
"""
result = OrderedSet(self.parents)
for parent in self.parents:
for ancestor in parent._meta.get_parent_list():
result.add(ancestor)
return list(result)
def get_ancestor_link(self, ancestor):
"""
Return the field on the current model which points to the given
"ancestor". This is possible an indirect link (a pointer to a parent
model, which points, eventually, to the ancestor). Used when
constructing table joins for model inheritance.
Return None if the model isn't an ancestor of this one.
"""
if ancestor in self.parents:
return self.parents[ancestor]
for parent in self.parents:
# Tries to get a link field from the immediate parent
parent_link = parent._meta.get_ancestor_link(ancestor)
if parent_link:
# In case of a proxied model, the first link
# of the chain to the ancestor is that parent
# links
return self.parents[parent] or parent_link
def get_path_to_parent(self, parent):
"""
Return a list of PathInfos containing the path from the current
model to the parent model, or an empty list if parent is not a
parent of the current model.
"""
if self.model is parent:
return []
# Skip the chain of proxy to the concrete proxied model.
proxied_model = self.concrete_model
path = []
opts = self
for int_model in self.get_base_chain(parent):
if int_model is proxied_model:
opts = int_model._meta
else:
final_field = opts.parents[int_model]
targets = (final_field.remote_field.get_related_field(),)
opts = int_model._meta
path.append(PathInfo(
from_opts=final_field.model._meta,
to_opts=opts,
target_fields=targets,
join_field=final_field,
m2m=False,
direct=True,
filtered_relation=None,
))
return path
def get_path_from_parent(self, parent):
"""
Return a list of PathInfos containing the path from the parent
model to the current model, or an empty list if parent is not a
parent of the current model.
"""
if self.model is parent:
return []
model = self.concrete_model
# Get a reversed base chain including both the current and parent
# models.
chain = model._meta.get_base_chain(parent)
chain.reverse()
chain.append(model)
# Construct a list of the PathInfos between models in chain.
path = []
for i, ancestor in enumerate(chain[:-1]):
child = chain[i + 1]
link = child._meta.get_ancestor_link(ancestor)
path.extend(link.get_reverse_path_info())
return path
def _populate_directed_relation_graph(self):
"""
This method is used by each model to find its reverse objects. As this
method is very expensive and is accessed frequently (it looks up every
field in a model, in every app), it is computed on first access and then
is set as a property on every model.
"""
related_objects_graph = defaultdict(list)
all_models = self.apps.get_models(include_auto_created=True)
for model in all_models:
opts = model._meta
# Abstract model's fields are copied to child models, hence we will
# see the fields from the child models.
if opts.abstract:
continue
fields_with_relations = (
f for f in opts._get_fields(reverse=False, include_parents=False)
if f.is_relation and f.related_model is not None
)
for f in fields_with_relations:
if not isinstance(f.remote_field.model, str):
related_objects_graph[f.remote_field.model._meta.concrete_model._meta].append(f)
for model in all_models:
# Set the relation_tree using the internal __dict__. In this way
# we avoid calling the cached property. In attribute lookup,
# __dict__ takes precedence over a data descriptor (such as
# @cached_property). This means that the _meta._relation_tree is
# only called if related_objects is not in __dict__.
related_objects = related_objects_graph[model._meta.concrete_model._meta]
model._meta.__dict__['_relation_tree'] = related_objects
# It seems it is possible that self is not in all_models, so guard
# against that with default for get().
return self.__dict__.get('_relation_tree', EMPTY_RELATION_TREE)
@cached_property
def _relation_tree(self):
return self._populate_directed_relation_graph()
def _expire_cache(self, forward=True, reverse=True):
# This method is usually called by apps.cache_clear(), when the
# registry is finalized, or when a new field is added.
if forward:
for cache_key in self.FORWARD_PROPERTIES:
if cache_key in self.__dict__:
delattr(self, cache_key)
if reverse and not self.abstract:
for cache_key in self.REVERSE_PROPERTIES:
if cache_key in self.__dict__:
delattr(self, cache_key)
self._get_fields_cache = {}
def get_fields(self, include_parents=True, include_hidden=False):
"""
Return a list of fields associated to the model. By default, include
forward and reverse fields, fields derived from inheritance, but not
hidden fields. The returned fields can be changed using the parameters:
- include_parents: include fields derived from inheritance
- include_hidden: include fields that have a related_name that
starts with a "+"
"""
if include_parents is False:
include_parents = PROXY_PARENTS
return self._get_fields(include_parents=include_parents, include_hidden=include_hidden)
def _get_fields(self, forward=True, reverse=True, include_parents=True, include_hidden=False,
seen_models=None):
"""
Internal helper function to return fields of the model.
* If forward=True, then fields defined on this model are returned.
* If reverse=True, then relations pointing to this model are returned.
* If include_hidden=True, then fields with is_hidden=True are returned.
* The include_parents argument toggles if fields from parent models
should be included. It has three values: True, False, and
PROXY_PARENTS. When set to PROXY_PARENTS, the call will return all
fields defined for the current model or any of its parents in the
parent chain to the model's concrete model.
"""
if include_parents not in (True, False, PROXY_PARENTS):
raise TypeError("Invalid argument for include_parents: %s" % (include_parents,))
# This helper function is used to allow recursion in ``get_fields()``
# implementation and to provide a fast way for Django's internals to
# access specific subsets of fields.
# We must keep track of which models we have already seen. Otherwise we
# could include the same field multiple times from different models.
topmost_call = seen_models is None
if topmost_call:
seen_models = set()
seen_models.add(self.model)
# Creates a cache key composed of all arguments
cache_key = (forward, reverse, include_parents, include_hidden, topmost_call)
try:
# In order to avoid list manipulation. Always return a shallow copy
# of the results.
return self._get_fields_cache[cache_key]
except KeyError:
pass
fields = []
# Recursively call _get_fields() on each parent, with the same
# options provided in this call.
if include_parents is not False:
for parent in self.parents:
# In diamond inheritance it is possible that we see the same
# model from two different routes. In that case, avoid adding
# fields from the same parent again.
if parent in seen_models:
continue
if (parent._meta.concrete_model != self.concrete_model and
include_parents == PROXY_PARENTS):
continue
for obj in parent._meta._get_fields(
forward=forward, reverse=reverse, include_parents=include_parents,
include_hidden=include_hidden, seen_models=seen_models):
if not getattr(obj, 'parent_link', False) or obj.model == self.concrete_model:
fields.append(obj)
if reverse and not self.proxy:
# Tree is computed once and cached until the app cache is expired.
# It is composed of a list of fields pointing to the current model
# from other models.
all_fields = self._relation_tree
for field in all_fields:
# If hidden fields should be included or the relation is not
# intentionally hidden, add to the fields dict.
if include_hidden or not field.remote_field.hidden:
fields.append(field.remote_field)
if forward:
fields += self.local_fields
fields += self.local_many_to_many
# Private fields are recopied to each child model, and they get a
# different model as field.model in each child. Hence we have to
# add the private fields separately from the topmost call. If we
# did this recursively similar to local_fields, we would get field
# instances with field.model != self.model.
if topmost_call:
fields += self.private_fields
# In order to avoid list manipulation. Always
# return a shallow copy of the results
fields = make_immutable_fields_list("get_fields()", fields)
# Store result into cache for later access
self._get_fields_cache[cache_key] = fields
return fields
@cached_property
def _property_names(self):
"""Return a set of the names of the properties defined on the model."""
names = []
for name in dir(self.model):
attr = inspect.getattr_static(self.model, name)
if isinstance(attr, property):
names.append(name)
return frozenset(names)
|
7171b497a5672bd1de85efdc3054ded701ac03e826850b3bc21582d9d9832f4d | import copy
import inspect
import warnings
from functools import partialmethod
from itertools import chain
from django.apps import apps
from django.conf import settings
from django.core import checks
from django.core.exceptions import (
NON_FIELD_ERRORS, FieldDoesNotExist, FieldError, MultipleObjectsReturned,
ObjectDoesNotExist, ValidationError,
)
from django.db import (
DEFAULT_DB_ALIAS, DJANGO_VERSION_PICKLE_KEY, DatabaseError, connection,
connections, router, transaction,
)
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import CASCADE, Collector
from django.db.models.fields.related import (
ForeignObjectRel, OneToOneField, lazy_related_operation, resolve_relation,
)
from django.db.models.manager import Manager
from django.db.models.options import Options
from django.db.models.query import Q
from django.db.models.signals import (
class_prepared, post_init, post_save, pre_init, pre_save,
)
from django.db.models.utils import make_model_tuple
from django.utils.encoding import force_text
from django.utils.text import capfirst, get_text_list
from django.utils.translation import gettext_lazy as _
from django.utils.version import get_version
class Deferred:
def __repr__(self):
return '<Deferred field>'
def __str__(self):
return '<Deferred field>'
DEFERRED = Deferred()
def subclass_exception(name, bases, module, attached_to):
"""
Create exception subclass. Used by ModelBase below.
The exception is created in a way that allows it to be pickled, assuming
that the returned exception class will be added as an attribute to the
'attached_to' class.
"""
return type(name, bases, {
'__module__': module,
'__qualname__': '%s.%s' % (attached_to.__qualname__, name),
})
class ModelBase(type):
"""Metaclass for all models."""
def __new__(cls, name, bases, attrs, **kwargs):
super_new = super().__new__
# Also ensure initialization is only performed for subclasses of Model
# (excluding Model class itself).
parents = [b for b in bases if isinstance(b, ModelBase)]
if not parents:
return super_new(cls, name, bases, attrs)
# Create the class.
module = attrs.pop('__module__')
new_attrs = {'__module__': module}
classcell = attrs.pop('__classcell__', None)
if classcell is not None:
new_attrs['__classcell__'] = classcell
new_class = super_new(cls, name, bases, new_attrs, **kwargs)
attr_meta = attrs.pop('Meta', None)
abstract = getattr(attr_meta, 'abstract', False)
meta = attr_meta or getattr(new_class, 'Meta', None)
base_meta = getattr(new_class, '_meta', None)
app_label = None
# Look for an application configuration to attach the model to.
app_config = apps.get_containing_app_config(module)
if getattr(meta, 'app_label', None) is None:
if app_config is None:
if not abstract:
raise RuntimeError(
"Model class %s.%s doesn't declare an explicit "
"app_label and isn't in an application in "
"INSTALLED_APPS." % (module, name)
)
else:
app_label = app_config.label
new_class.add_to_class('_meta', Options(meta, app_label))
if not abstract:
new_class.add_to_class(
'DoesNotExist',
subclass_exception(
'DoesNotExist',
tuple(
x.DoesNotExist for x in parents if hasattr(x, '_meta') and not x._meta.abstract
) or (ObjectDoesNotExist,),
module,
attached_to=new_class))
new_class.add_to_class(
'MultipleObjectsReturned',
subclass_exception(
'MultipleObjectsReturned',
tuple(
x.MultipleObjectsReturned for x in parents if hasattr(x, '_meta') and not x._meta.abstract
) or (MultipleObjectsReturned,),
module,
attached_to=new_class))
if base_meta and not base_meta.abstract:
# Non-abstract child classes inherit some attributes from their
# non-abstract parent (unless an ABC comes before it in the
# method resolution order).
if not hasattr(meta, 'ordering'):
new_class._meta.ordering = base_meta.ordering
if not hasattr(meta, 'get_latest_by'):
new_class._meta.get_latest_by = base_meta.get_latest_by
is_proxy = new_class._meta.proxy
# If the model is a proxy, ensure that the base class
# hasn't been swapped out.
if is_proxy and base_meta and base_meta.swapped:
raise TypeError("%s cannot proxy the swapped model '%s'." % (name, base_meta.swapped))
# Add all attributes to the class.
for obj_name, obj in attrs.items():
new_class.add_to_class(obj_name, obj)
# All the fields of any type declared on this model
new_fields = chain(
new_class._meta.local_fields,
new_class._meta.local_many_to_many,
new_class._meta.private_fields
)
field_names = {f.name for f in new_fields}
# Basic setup for proxy models.
if is_proxy:
base = None
for parent in [kls for kls in parents if hasattr(kls, '_meta')]:
if parent._meta.abstract:
if parent._meta.fields:
raise TypeError(
"Abstract base class containing model fields not "
"permitted for proxy model '%s'." % name
)
else:
continue
if base is None:
base = parent
elif parent._meta.concrete_model is not base._meta.concrete_model:
raise TypeError("Proxy model '%s' has more than one non-abstract model base class." % name)
if base is None:
raise TypeError("Proxy model '%s' has no non-abstract model base class." % name)
new_class._meta.setup_proxy(base)
new_class._meta.concrete_model = base._meta.concrete_model
else:
new_class._meta.concrete_model = new_class
# Collect the parent links for multi-table inheritance.
parent_links = {}
for base in reversed([new_class] + parents):
# Conceptually equivalent to `if base is Model`.
if not hasattr(base, '_meta'):
continue
# Skip concrete parent classes.
if base != new_class and not base._meta.abstract:
continue
# Locate OneToOneField instances.
for field in base._meta.local_fields:
if isinstance(field, OneToOneField):
related = resolve_relation(new_class, field.remote_field.model)
parent_links[make_model_tuple(related)] = field
# Track fields inherited from base models.
inherited_attributes = set()
# Do the appropriate setup for any model parents.
for base in new_class.mro():
if base not in parents or not hasattr(base, '_meta'):
# Things without _meta aren't functional models, so they're
# uninteresting parents.
inherited_attributes.update(base.__dict__)
continue
parent_fields = base._meta.local_fields + base._meta.local_many_to_many
if not base._meta.abstract:
# Check for clashes between locally declared fields and those
# on the base classes.
for field in parent_fields:
if field.name in field_names:
raise FieldError(
'Local field %r in class %r clashes with field of '
'the same name from base class %r.' % (
field.name,
name,
base.__name__,
)
)
else:
inherited_attributes.add(field.name)
# Concrete classes...
base = base._meta.concrete_model
base_key = make_model_tuple(base)
if base_key in parent_links:
field = parent_links[base_key]
elif not is_proxy:
attr_name = '%s_ptr' % base._meta.model_name
field = OneToOneField(
base,
on_delete=CASCADE,
name=attr_name,
auto_created=True,
parent_link=True,
)
if attr_name in field_names:
raise FieldError(
"Auto-generated field '%s' in class %r for "
"parent_link to base class %r clashes with "
"declared field of the same name." % (
attr_name,
name,
base.__name__,
)
)
# Only add the ptr field if it's not already present;
# e.g. migrations will already have it specified
if not hasattr(new_class, attr_name):
new_class.add_to_class(attr_name, field)
else:
field = None
new_class._meta.parents[base] = field
else:
base_parents = base._meta.parents.copy()
# Add fields from abstract base class if it wasn't overridden.
for field in parent_fields:
if (field.name not in field_names and
field.name not in new_class.__dict__ and
field.name not in inherited_attributes):
new_field = copy.deepcopy(field)
new_class.add_to_class(field.name, new_field)
# Replace parent links defined on this base by the new
# field. It will be appropriately resolved if required.
if field.one_to_one:
for parent, parent_link in base_parents.items():
if field == parent_link:
base_parents[parent] = new_field
# Pass any non-abstract parent classes onto child.
new_class._meta.parents.update(base_parents)
# Inherit private fields (like GenericForeignKey) from the parent
# class
for field in base._meta.private_fields:
if field.name in field_names:
if not base._meta.abstract:
raise FieldError(
'Local field %r in class %r clashes with field of '
'the same name from base class %r.' % (
field.name,
name,
base.__name__,
)
)
else:
field = copy.deepcopy(field)
field.mti_inherited = True
new_class.add_to_class(field.name, field)
# Copy indexes so that index names are unique when models extend an
# abstract model.
new_class._meta.indexes = [copy.deepcopy(idx) for idx in new_class._meta.indexes]
if abstract:
# Abstract base models can't be instantiated and don't appear in
# the list of models for an app. We do the final setup for them a
# little differently from normal models.
attr_meta.abstract = False
new_class.Meta = attr_meta
return new_class
new_class._prepare()
new_class._meta.apps.register_model(new_class._meta.app_label, new_class)
return new_class
def add_to_class(cls, name, value):
# We should call the contribute_to_class method only if it's bound
if not inspect.isclass(value) and hasattr(value, 'contribute_to_class'):
value.contribute_to_class(cls, name)
else:
setattr(cls, name, value)
def _prepare(cls):
"""Create some methods once self._meta has been populated."""
opts = cls._meta
opts._prepare(cls)
if opts.order_with_respect_to:
cls.get_next_in_order = partialmethod(cls._get_next_or_previous_in_order, is_next=True)
cls.get_previous_in_order = partialmethod(cls._get_next_or_previous_in_order, is_next=False)
# Defer creating accessors on the foreign class until it has been
# created and registered. If remote_field is None, we're ordering
# with respect to a GenericForeignKey and don't know what the
# foreign class is - we'll add those accessors later in
# contribute_to_class().
if opts.order_with_respect_to.remote_field:
wrt = opts.order_with_respect_to
remote = wrt.remote_field.model
lazy_related_operation(make_foreign_order_accessors, cls, remote)
# Give the class a docstring -- its definition.
if cls.__doc__ is None:
cls.__doc__ = "%s(%s)" % (cls.__name__, ", ".join(f.name for f in opts.fields))
get_absolute_url_override = settings.ABSOLUTE_URL_OVERRIDES.get(opts.label_lower)
if get_absolute_url_override:
setattr(cls, 'get_absolute_url', get_absolute_url_override)
if not opts.managers:
if any(f.name == 'objects' for f in opts.fields):
raise ValueError(
"Model %s must specify a custom Manager, because it has a "
"field named 'objects'." % cls.__name__
)
manager = Manager()
manager.auto_created = True
cls.add_to_class('objects', manager)
# Set the name of _meta.indexes. This can't be done in
# Options.contribute_to_class() because fields haven't been added to
# the model at that point.
for index in cls._meta.indexes:
if not index.name:
index.set_name_with_model(cls)
class_prepared.send(sender=cls)
@property
def _base_manager(cls):
return cls._meta.base_manager
@property
def _default_manager(cls):
return cls._meta.default_manager
class ModelStateFieldsCacheDescriptor:
def __get__(self, instance, cls=None):
if instance is None:
return self
res = instance.fields_cache = {}
return res
class ModelState:
"""Store model instance state."""
db = None
# If true, uniqueness validation checks will consider this a new, unsaved
# object. Necessary for correct validation of new instances of objects with
# explicit (non-auto) PKs. This impacts validation only; it has no effect
# on the actual save.
adding = True
fields_cache = ModelStateFieldsCacheDescriptor()
class Model(metaclass=ModelBase):
def __init__(self, *args, **kwargs):
# Alias some things as locals to avoid repeat global lookups
cls = self.__class__
opts = self._meta
_setattr = setattr
_DEFERRED = DEFERRED
pre_init.send(sender=cls, args=args, kwargs=kwargs)
# Set up the storage for instance state
self._state = ModelState()
# There is a rather weird disparity here; if kwargs, it's set, then args
# overrides it. It should be one or the other; don't duplicate the work
# The reason for the kwargs check is that standard iterator passes in by
# args, and instantiation for iteration is 33% faster.
if len(args) > len(opts.concrete_fields):
# Daft, but matches old exception sans the err msg.
raise IndexError("Number of args exceeds number of fields")
if not kwargs:
fields_iter = iter(opts.concrete_fields)
# The ordering of the zip calls matter - zip throws StopIteration
# when an iter throws it. So if the first iter throws it, the second
# is *not* consumed. We rely on this, so don't change the order
# without changing the logic.
for val, field in zip(args, fields_iter):
if val is _DEFERRED:
continue
_setattr(self, field.attname, val)
else:
# Slower, kwargs-ready version.
fields_iter = iter(opts.fields)
for val, field in zip(args, fields_iter):
if val is _DEFERRED:
continue
_setattr(self, field.attname, val)
kwargs.pop(field.name, None)
# Now we're left with the unprocessed fields that *must* come from
# keywords, or default.
for field in fields_iter:
is_related_object = False
# Virtual field
if field.attname not in kwargs and field.column is None:
continue
if kwargs:
if isinstance(field.remote_field, ForeignObjectRel):
try:
# Assume object instance was passed in.
rel_obj = kwargs.pop(field.name)
is_related_object = True
except KeyError:
try:
# Object instance wasn't passed in -- must be an ID.
val = kwargs.pop(field.attname)
except KeyError:
val = field.get_default()
else:
# Object instance was passed in. Special case: You can
# pass in "None" for related objects if it's allowed.
if rel_obj is None and field.null:
val = None
else:
try:
val = kwargs.pop(field.attname)
except KeyError:
# This is done with an exception rather than the
# default argument on pop because we don't want
# get_default() to be evaluated, and then not used.
# Refs #12057.
val = field.get_default()
else:
val = field.get_default()
if is_related_object:
# If we are passed a related instance, set it using the
# field.name instead of field.attname (e.g. "user" instead of
# "user_id") so that the object gets properly cached (and type
# checked) by the RelatedObjectDescriptor.
if rel_obj is not _DEFERRED:
_setattr(self, field.name, rel_obj)
else:
if val is not _DEFERRED:
_setattr(self, field.attname, val)
if kwargs:
property_names = opts._property_names
for prop in tuple(kwargs):
try:
# Any remaining kwargs must correspond to properties or
# virtual fields.
if prop in property_names or opts.get_field(prop):
if kwargs[prop] is not _DEFERRED:
_setattr(self, prop, kwargs[prop])
del kwargs[prop]
except (AttributeError, FieldDoesNotExist):
pass
for kwarg in kwargs:
raise TypeError("%s() got an unexpected keyword argument '%s'" % (cls.__name__, kwarg))
super().__init__()
post_init.send(sender=cls, instance=self)
@classmethod
def from_db(cls, db, field_names, values):
if len(values) != len(cls._meta.concrete_fields):
values_iter = iter(values)
values = [
next(values_iter) if f.attname in field_names else DEFERRED
for f in cls._meta.concrete_fields
]
new = cls(*values)
new._state.adding = False
new._state.db = db
return new
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self)
def __str__(self):
return '%s object (%s)' % (self.__class__.__name__, self.pk)
def __eq__(self, other):
if not isinstance(other, Model):
return False
if self._meta.concrete_model != other._meta.concrete_model:
return False
my_pk = self.pk
if my_pk is None:
return self is other
return my_pk == other.pk
def __hash__(self):
if self.pk is None:
raise TypeError("Model instances without primary key value are unhashable")
return hash(self.pk)
def __reduce__(self):
data = self.__getstate__()
data[DJANGO_VERSION_PICKLE_KEY] = get_version()
class_id = self._meta.app_label, self._meta.object_name
return model_unpickle, (class_id,), data
def __getstate__(self):
"""Hook to allow choosing the attributes to pickle."""
return self.__dict__
def __setstate__(self, state):
msg = None
pickled_version = state.get(DJANGO_VERSION_PICKLE_KEY)
if pickled_version:
current_version = get_version()
if current_version != pickled_version:
msg = (
"Pickled model instance's Django version %s does not match "
"the current version %s." % (pickled_version, current_version)
)
else:
msg = "Pickled model instance's Django version is not specified."
if msg:
warnings.warn(msg, RuntimeWarning, stacklevel=2)
self.__dict__.update(state)
def _get_pk_val(self, meta=None):
meta = meta or self._meta
return getattr(self, meta.pk.attname)
def _set_pk_val(self, value):
return setattr(self, self._meta.pk.attname, value)
pk = property(_get_pk_val, _set_pk_val)
def get_deferred_fields(self):
"""
Return a set containing names of deferred fields for this instance.
"""
return {
f.attname for f in self._meta.concrete_fields
if f.attname not in self.__dict__
}
def refresh_from_db(self, using=None, fields=None):
"""
Reload field values from the database.
By default, the reloading happens from the database this instance was
loaded from, or by the read router if this instance wasn't loaded from
any database. The using parameter will override the default.
Fields can be used to specify which fields to reload. The fields
should be an iterable of field attnames. If fields is None, then
all non-deferred fields are reloaded.
When accessing deferred fields of an instance, the deferred loading
of the field will call this method.
"""
if fields is not None:
if not fields:
return
if any(LOOKUP_SEP in f for f in fields):
raise ValueError(
'Found "%s" in fields argument. Relations and transforms '
'are not allowed in fields.' % LOOKUP_SEP)
hints = {'instance': self}
db_instance_qs = self.__class__._base_manager.db_manager(using, hints=hints).filter(pk=self.pk)
# Use provided fields, if not set then reload all non-deferred fields.
deferred_fields = self.get_deferred_fields()
if fields is not None:
fields = list(fields)
db_instance_qs = db_instance_qs.only(*fields)
elif deferred_fields:
fields = [f.attname for f in self._meta.concrete_fields
if f.attname not in deferred_fields]
db_instance_qs = db_instance_qs.only(*fields)
db_instance = db_instance_qs.get()
non_loaded_fields = db_instance.get_deferred_fields()
for field in self._meta.concrete_fields:
if field.attname in non_loaded_fields:
# This field wasn't refreshed - skip ahead.
continue
setattr(self, field.attname, getattr(db_instance, field.attname))
# Clear cached foreign keys.
if field.is_relation and field.is_cached(self):
field.delete_cached_value(self)
# Clear cached relations.
for field in self._meta.related_objects:
if field.is_cached(self):
field.delete_cached_value(self)
self._state.db = db_instance._state.db
def serializable_value(self, field_name):
"""
Return the value of the field name for this instance. If the field is
a foreign key, return the id value instead of the object. If there's
no Field object with this name on the model, return the model
attribute's value.
Used to serialize a field's value (in the serializer, or form output,
for example). Normally, you would just access the attribute directly
and not use this method.
"""
try:
field = self._meta.get_field(field_name)
except FieldDoesNotExist:
return getattr(self, field_name)
return getattr(self, field.attname)
def save(self, force_insert=False, force_update=False, using=None,
update_fields=None):
"""
Save the current instance. Override this in a subclass if you want to
control the saving process.
The 'force_insert' and 'force_update' parameters can be used to insist
that the "save" must be an SQL insert or update (or equivalent for
non-SQL backends), respectively. Normally, they should not be set.
"""
# Ensure that a model instance without a PK hasn't been assigned to
# a ForeignKey or OneToOneField on this model. If the field is
# nullable, allowing the save() would result in silent data loss.
for field in self._meta.concrete_fields:
# If the related field isn't cached, then an instance hasn't
# been assigned and there's no need to worry about this check.
if field.is_relation and field.is_cached(self):
obj = getattr(self, field.name, None)
# A pk may have been assigned manually to a model instance not
# saved to the database (or auto-generated in a case like
# UUIDField), but we allow the save to proceed and rely on the
# database to raise an IntegrityError if applicable. If
# constraints aren't supported by the database, there's the
# unavoidable risk of data corruption.
if obj and obj.pk is None:
# Remove the object from a related instance cache.
if not field.remote_field.multiple:
field.remote_field.delete_cached_value(obj)
raise ValueError(
"save() prohibited to prevent data loss due to "
"unsaved related object '%s'." % field.name
)
# If the relationship's pk was changed, clear the cached
# relationship.
if obj and obj.pk != getattr(self, field.attname):
field.delete_cached_value(self)
using = using or router.db_for_write(self.__class__, instance=self)
if force_insert and (force_update or update_fields):
raise ValueError("Cannot force both insert and updating in model saving.")
deferred_fields = self.get_deferred_fields()
if update_fields is not None:
# If update_fields is empty, skip the save. We do also check for
# no-op saves later on for inheritance cases. This bailout is
# still needed for skipping signal sending.
if not update_fields:
return
update_fields = frozenset(update_fields)
field_names = set()
for field in self._meta.fields:
if not field.primary_key:
field_names.add(field.name)
if field.name != field.attname:
field_names.add(field.attname)
non_model_fields = update_fields.difference(field_names)
if non_model_fields:
raise ValueError("The following fields do not exist in this "
"model or are m2m fields: %s"
% ', '.join(non_model_fields))
# If saving to the same database, and this model is deferred, then
# automatically do a "update_fields" save on the loaded fields.
elif not force_insert and deferred_fields and using == self._state.db:
field_names = set()
for field in self._meta.concrete_fields:
if not field.primary_key and not hasattr(field, 'through'):
field_names.add(field.attname)
loaded_fields = field_names.difference(deferred_fields)
if loaded_fields:
update_fields = frozenset(loaded_fields)
self.save_base(using=using, force_insert=force_insert,
force_update=force_update, update_fields=update_fields)
save.alters_data = True
def save_base(self, raw=False, force_insert=False,
force_update=False, using=None, update_fields=None):
"""
Handle the parts of saving which should be done only once per save,
yet need to be done in raw saves, too. This includes some sanity
checks and signal sending.
The 'raw' argument is telling save_base not to save any parent
models and not to do any changes to the values before save. This
is used by fixture loading.
"""
using = using or router.db_for_write(self.__class__, instance=self)
assert not (force_insert and (force_update or update_fields))
assert update_fields is None or update_fields
cls = origin = self.__class__
# Skip proxies, but keep the origin as the proxy model.
if cls._meta.proxy:
cls = cls._meta.concrete_model
meta = cls._meta
if not meta.auto_created:
pre_save.send(
sender=origin, instance=self, raw=raw, using=using,
update_fields=update_fields,
)
with transaction.atomic(using=using, savepoint=False):
if not raw:
self._save_parents(cls, using, update_fields)
updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
# Store the database on which the object was saved
self._state.db = using
# Once saved, this is no longer a to-be-added instance.
self._state.adding = False
# Signal that the save is complete
if not meta.auto_created:
post_save.send(
sender=origin, instance=self, created=(not updated),
update_fields=update_fields, raw=raw, using=using,
)
save_base.alters_data = True
def _save_parents(self, cls, using, update_fields):
"""Save all the parents of cls using values from self."""
meta = cls._meta
for parent, field in meta.parents.items():
# Make sure the link fields are synced between parent and self.
if (field and getattr(self, parent._meta.pk.attname) is None and
getattr(self, field.attname) is not None):
setattr(self, parent._meta.pk.attname, getattr(self, field.attname))
self._save_parents(cls=parent, using=using, update_fields=update_fields)
self._save_table(cls=parent, using=using, update_fields=update_fields)
# Set the parent's PK value to self.
if field:
setattr(self, field.attname, self._get_pk_val(parent._meta))
# Since we didn't have an instance of the parent handy set
# attname directly, bypassing the descriptor. Invalidate
# the related object cache, in case it's been accidentally
# populated. A fresh instance will be re-built from the
# database if necessary.
if field.is_cached(self):
field.delete_cached_value(self)
def _save_table(self, raw=False, cls=None, force_insert=False,
force_update=False, using=None, update_fields=None):
"""
Do the heavy-lifting involved in saving. Update or insert the data
for a single table.
"""
meta = cls._meta
non_pks = [f for f in meta.local_concrete_fields if not f.primary_key]
if update_fields:
non_pks = [f for f in non_pks
if f.name in update_fields or f.attname in update_fields]
pk_val = self._get_pk_val(meta)
if pk_val is None:
pk_val = meta.pk.get_pk_value_on_save(self)
setattr(self, meta.pk.attname, pk_val)
pk_set = pk_val is not None
if not pk_set and (force_update or update_fields):
raise ValueError("Cannot force an update in save() with no primary key.")
updated = False
# If possible, try an UPDATE. If that doesn't update anything, do an INSERT.
if pk_set and not force_insert:
base_qs = cls._base_manager.using(using)
values = [(f, None, (getattr(self, f.attname) if raw else f.pre_save(self, False)))
for f in non_pks]
forced_update = update_fields or force_update
updated = self._do_update(base_qs, using, pk_val, values, update_fields,
forced_update)
if force_update and not updated:
raise DatabaseError("Forced update did not affect any rows.")
if update_fields and not updated:
raise DatabaseError("Save with update_fields did not affect any rows.")
if not updated:
if meta.order_with_respect_to:
# If this is a model with an order_with_respect_to
# autopopulate the _order field
field = meta.order_with_respect_to
filter_args = field.get_filter_kwargs_for_object(self)
order_value = cls._base_manager.using(using).filter(**filter_args).count()
self._order = order_value
fields = meta.local_concrete_fields
if not pk_set:
fields = [f for f in fields if f is not meta.auto_field]
update_pk = meta.auto_field and not pk_set
result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
if update_pk:
setattr(self, meta.pk.attname, result)
return updated
def _do_update(self, base_qs, using, pk_val, values, update_fields, forced_update):
"""
Try to update the model. Return True if the model was updated (if an
update query was done and a matching row was found in the DB).
"""
filtered = base_qs.filter(pk=pk_val)
if not values:
# We can end up here when saving a model in inheritance chain where
# update_fields doesn't target any field in current model. In that
# case we just say the update succeeded. Another case ending up here
# is a model with just PK - in that case check that the PK still
# exists.
return update_fields is not None or filtered.exists()
if self._meta.select_on_save and not forced_update:
return (
filtered.exists() and
# It may happen that the object is deleted from the DB right after
# this check, causing the subsequent UPDATE to return zero matching
# rows. The same result can occur in some rare cases when the
# database returns zero despite the UPDATE being executed
# successfully (a row is matched and updated). In order to
# distinguish these two cases, the object's existence in the
# database is again checked for if the UPDATE query returns 0.
(filtered._update(values) > 0 or filtered.exists())
)
return filtered._update(values) > 0
def _do_insert(self, manager, using, fields, update_pk, raw):
"""
Do an INSERT. If update_pk is defined then this method should return
the new pk for the model.
"""
return manager._insert([self], fields=fields, return_id=update_pk,
using=using, raw=raw)
def delete(self, using=None, keep_parents=False):
using = using or router.db_for_write(self.__class__, instance=self)
assert self.pk is not None, (
"%s object can't be deleted because its %s attribute is set to None." %
(self._meta.object_name, self._meta.pk.attname)
)
collector = Collector(using=using)
collector.collect([self], keep_parents=keep_parents)
return collector.delete()
delete.alters_data = True
def _get_FIELD_display(self, field):
value = getattr(self, field.attname)
return force_text(dict(field.flatchoices).get(value, value), strings_only=True)
def _get_next_or_previous_by_FIELD(self, field, is_next, **kwargs):
if not self.pk:
raise ValueError("get_next/get_previous cannot be used on unsaved objects.")
op = 'gt' if is_next else 'lt'
order = '' if is_next else '-'
param = getattr(self, field.attname)
q = Q(**{'%s__%s' % (field.name, op): param})
q = q | Q(**{field.name: param, 'pk__%s' % op: self.pk})
qs = self.__class__._default_manager.using(self._state.db).filter(**kwargs).filter(q).order_by(
'%s%s' % (order, field.name), '%spk' % order
)
try:
return qs[0]
except IndexError:
raise self.DoesNotExist("%s matching query does not exist." % self.__class__._meta.object_name)
def _get_next_or_previous_in_order(self, is_next):
cachename = "__%s_order_cache" % is_next
if not hasattr(self, cachename):
op = 'gt' if is_next else 'lt'
order = '_order' if is_next else '-_order'
order_field = self._meta.order_with_respect_to
filter_args = order_field.get_filter_kwargs_for_object(self)
obj = self.__class__._default_manager.filter(**filter_args).filter(**{
'_order__%s' % op: self.__class__._default_manager.values('_order').filter(**{
self._meta.pk.name: self.pk
})
}).order_by(order)[:1].get()
setattr(self, cachename, obj)
return getattr(self, cachename)
def prepare_database_save(self, field):
if self.pk is None:
raise ValueError("Unsaved model instance %r cannot be used in an ORM query." % self)
return getattr(self, field.remote_field.get_related_field().attname)
def clean(self):
"""
Hook for doing any extra model-wide validation after clean() has been
called on every field by self.clean_fields. Any ValidationError raised
by this method will not be associated with a particular field; it will
have a special-case association with the field defined by NON_FIELD_ERRORS.
"""
pass
def validate_unique(self, exclude=None):
"""
Check unique constraints on the model and raise ValidationError if any
failed.
"""
unique_checks, date_checks = self._get_unique_checks(exclude=exclude)
errors = self._perform_unique_checks(unique_checks)
date_errors = self._perform_date_checks(date_checks)
for k, v in date_errors.items():
errors.setdefault(k, []).extend(v)
if errors:
raise ValidationError(errors)
def _get_unique_checks(self, exclude=None):
"""
Return a list of checks to perform. Since validate_unique() could be
called from a ModelForm, some fields may have been excluded; we can't
perform a unique check on a model that is missing fields involved
in that check. Fields that did not validate should also be excluded,
but they need to be passed in via the exclude argument.
"""
if exclude is None:
exclude = []
unique_checks = []
unique_togethers = [(self.__class__, self._meta.unique_together)]
for parent_class in self._meta.get_parent_list():
if parent_class._meta.unique_together:
unique_togethers.append((parent_class, parent_class._meta.unique_together))
for model_class, unique_together in unique_togethers:
for check in unique_together:
if not any(name in exclude for name in check):
# Add the check if the field isn't excluded.
unique_checks.append((model_class, tuple(check)))
# These are checks for the unique_for_<date/year/month>.
date_checks = []
# Gather a list of checks for fields declared as unique and add them to
# the list of checks.
fields_with_class = [(self.__class__, self._meta.local_fields)]
for parent_class in self._meta.get_parent_list():
fields_with_class.append((parent_class, parent_class._meta.local_fields))
for model_class, fields in fields_with_class:
for f in fields:
name = f.name
if name in exclude:
continue
if f.unique:
unique_checks.append((model_class, (name,)))
if f.unique_for_date and f.unique_for_date not in exclude:
date_checks.append((model_class, 'date', name, f.unique_for_date))
if f.unique_for_year and f.unique_for_year not in exclude:
date_checks.append((model_class, 'year', name, f.unique_for_year))
if f.unique_for_month and f.unique_for_month not in exclude:
date_checks.append((model_class, 'month', name, f.unique_for_month))
return unique_checks, date_checks
def _perform_unique_checks(self, unique_checks):
errors = {}
for model_class, unique_check in unique_checks:
# Try to look up an existing object with the same values as this
# object's values for all the unique field.
lookup_kwargs = {}
for field_name in unique_check:
f = self._meta.get_field(field_name)
lookup_value = getattr(self, f.attname)
# TODO: Handle multiple backends with different feature flags.
if (lookup_value is None or
(lookup_value == '' and connection.features.interprets_empty_strings_as_nulls)):
# no value, skip the lookup
continue
if f.primary_key and not self._state.adding:
# no need to check for unique primary key when editing
continue
lookup_kwargs[str(field_name)] = lookup_value
# some fields were skipped, no reason to do the check
if len(unique_check) != len(lookup_kwargs):
continue
qs = model_class._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
# Note that we need to use the pk as defined by model_class, not
# self.pk. These can be different fields because model inheritance
# allows single model to have effectively multiple primary keys.
# Refs #17615.
model_class_pk = self._get_pk_val(model_class._meta)
if not self._state.adding and model_class_pk is not None:
qs = qs.exclude(pk=model_class_pk)
if qs.exists():
if len(unique_check) == 1:
key = unique_check[0]
else:
key = NON_FIELD_ERRORS
errors.setdefault(key, []).append(self.unique_error_message(model_class, unique_check))
return errors
def _perform_date_checks(self, date_checks):
errors = {}
for model_class, lookup_type, field, unique_for in date_checks:
lookup_kwargs = {}
# there's a ticket to add a date lookup, we can remove this special
# case if that makes it's way in
date = getattr(self, unique_for)
if date is None:
continue
if lookup_type == 'date':
lookup_kwargs['%s__day' % unique_for] = date.day
lookup_kwargs['%s__month' % unique_for] = date.month
lookup_kwargs['%s__year' % unique_for] = date.year
else:
lookup_kwargs['%s__%s' % (unique_for, lookup_type)] = getattr(date, lookup_type)
lookup_kwargs[field] = getattr(self, field)
qs = model_class._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
if not self._state.adding and self.pk is not None:
qs = qs.exclude(pk=self.pk)
if qs.exists():
errors.setdefault(field, []).append(
self.date_error_message(lookup_type, field, unique_for)
)
return errors
def date_error_message(self, lookup_type, field_name, unique_for):
opts = self._meta
field = opts.get_field(field_name)
return ValidationError(
message=field.error_messages['unique_for_date'],
code='unique_for_date',
params={
'model': self,
'model_name': capfirst(opts.verbose_name),
'lookup_type': lookup_type,
'field': field_name,
'field_label': capfirst(field.verbose_name),
'date_field': unique_for,
'date_field_label': capfirst(opts.get_field(unique_for).verbose_name),
}
)
def unique_error_message(self, model_class, unique_check):
opts = model_class._meta
params = {
'model': self,
'model_class': model_class,
'model_name': capfirst(opts.verbose_name),
'unique_check': unique_check,
}
# A unique field
if len(unique_check) == 1:
field = opts.get_field(unique_check[0])
params['field_label'] = capfirst(field.verbose_name)
return ValidationError(
message=field.error_messages['unique'],
code='unique',
params=params,
)
# unique_together
else:
field_labels = [capfirst(opts.get_field(f).verbose_name) for f in unique_check]
params['field_labels'] = get_text_list(field_labels, _('and'))
return ValidationError(
message=_("%(model_name)s with this %(field_labels)s already exists."),
code='unique_together',
params=params,
)
def full_clean(self, exclude=None, validate_unique=True):
"""
Call clean_fields(), clean(), and validate_unique() on the model.
Raise a ValidationError for any errors that occur.
"""
errors = {}
if exclude is None:
exclude = []
else:
exclude = list(exclude)
try:
self.clean_fields(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
# Form.clean() is run even if other validation fails, so do the
# same with Model.clean() for consistency.
try:
self.clean()
except ValidationError as e:
errors = e.update_error_dict(errors)
# Run unique checks, but only for fields that passed validation.
if validate_unique:
for name in errors:
if name != NON_FIELD_ERRORS and name not in exclude:
exclude.append(name)
try:
self.validate_unique(exclude=exclude)
except ValidationError as e:
errors = e.update_error_dict(errors)
if errors:
raise ValidationError(errors)
def clean_fields(self, exclude=None):
"""
Clean all fields and raise a ValidationError containing a dict
of all validation errors if any occur.
"""
if exclude is None:
exclude = []
errors = {}
for f in self._meta.fields:
if f.name in exclude:
continue
# Skip validation for empty fields with blank=True. The developer
# is responsible for making sure they have a valid value.
raw_value = getattr(self, f.attname)
if f.blank and raw_value in f.empty_values:
continue
try:
setattr(self, f.attname, f.clean(raw_value, self))
except ValidationError as e:
errors[f.name] = e.error_list
if errors:
raise ValidationError(errors)
@classmethod
def check(cls, **kwargs):
errors = [*cls._check_swappable(), *cls._check_model(), *cls._check_managers(**kwargs)]
if not cls._meta.swapped:
errors += [
*cls._check_fields(**kwargs),
*cls._check_m2m_through_same_relationship(),
*cls._check_long_column_names(),
]
clash_errors = (
*cls._check_id_field(),
*cls._check_field_name_clashes(),
*cls._check_model_name_db_lookup_clashes(),
*cls._check_property_name_related_field_accessor_clashes(),
*cls._check_single_primary_key(),
)
errors.extend(clash_errors)
# If there are field name clashes, hide consequent column name
# clashes.
if not clash_errors:
errors.extend(cls._check_column_name_clashes())
errors += [
*cls._check_index_together(),
*cls._check_unique_together(),
*cls._check_indexes(),
*cls._check_ordering(),
]
return errors
@classmethod
def _check_swappable(cls):
"""Check if the swapped model exists."""
errors = []
if cls._meta.swapped:
try:
apps.get_model(cls._meta.swapped)
except ValueError:
errors.append(
checks.Error(
"'%s' is not of the form 'app_label.app_name'." % cls._meta.swappable,
id='models.E001',
)
)
except LookupError:
app_label, model_name = cls._meta.swapped.split('.')
errors.append(
checks.Error(
"'%s' references '%s.%s', which has not been "
"installed, or is abstract." % (
cls._meta.swappable, app_label, model_name
),
id='models.E002',
)
)
return errors
@classmethod
def _check_model(cls):
errors = []
if cls._meta.proxy:
if cls._meta.local_fields or cls._meta.local_many_to_many:
errors.append(
checks.Error(
"Proxy model '%s' contains model fields." % cls.__name__,
id='models.E017',
)
)
return errors
@classmethod
def _check_managers(cls, **kwargs):
"""Perform all manager checks."""
errors = []
for manager in cls._meta.managers:
errors.extend(manager.check(**kwargs))
return errors
@classmethod
def _check_fields(cls, **kwargs):
"""Perform all field checks."""
errors = []
for field in cls._meta.local_fields:
errors.extend(field.check(**kwargs))
for field in cls._meta.local_many_to_many:
errors.extend(field.check(from_model=cls, **kwargs))
return errors
@classmethod
def _check_m2m_through_same_relationship(cls):
""" Check if no relationship model is used by more than one m2m field.
"""
errors = []
seen_intermediary_signatures = []
fields = cls._meta.local_many_to_many
# Skip when the target model wasn't found.
fields = (f for f in fields if isinstance(f.remote_field.model, ModelBase))
# Skip when the relationship model wasn't found.
fields = (f for f in fields if isinstance(f.remote_field.through, ModelBase))
for f in fields:
signature = (f.remote_field.model, cls, f.remote_field.through)
if signature in seen_intermediary_signatures:
errors.append(
checks.Error(
"The model has two many-to-many relations through "
"the intermediate model '%s'." % f.remote_field.through._meta.label,
obj=cls,
id='models.E003',
)
)
else:
seen_intermediary_signatures.append(signature)
return errors
@classmethod
def _check_id_field(cls):
"""Check if `id` field is a primary key."""
fields = [f for f in cls._meta.local_fields if f.name == 'id' and f != cls._meta.pk]
# fields is empty or consists of the invalid "id" field
if fields and not fields[0].primary_key and cls._meta.pk.name == 'id':
return [
checks.Error(
"'id' can only be used as a field name if the field also "
"sets 'primary_key=True'.",
obj=cls,
id='models.E004',
)
]
else:
return []
@classmethod
def _check_field_name_clashes(cls):
"""Forbid field shadowing in multi-table inheritance."""
errors = []
used_fields = {} # name or attname -> field
# Check that multi-inheritance doesn't cause field name shadowing.
for parent in cls._meta.get_parent_list():
for f in parent._meta.local_fields:
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
if clash:
errors.append(
checks.Error(
"The field '%s' from parent model "
"'%s' clashes with the field '%s' "
"from parent model '%s'." % (
clash.name, clash.model._meta,
f.name, f.model._meta
),
obj=cls,
id='models.E005',
)
)
used_fields[f.name] = f
used_fields[f.attname] = f
# Check that fields defined in the model don't clash with fields from
# parents, including auto-generated fields like multi-table inheritance
# child accessors.
for parent in cls._meta.get_parent_list():
for f in parent._meta.get_fields():
if f not in used_fields:
used_fields[f.name] = f
for f in cls._meta.local_fields:
clash = used_fields.get(f.name) or used_fields.get(f.attname) or None
# Note that we may detect clash between user-defined non-unique
# field "id" and automatically added unique field "id", both
# defined at the same model. This special case is considered in
# _check_id_field and here we ignore it.
id_conflict = f.name == "id" and clash and clash.name == "id" and clash.model == cls
if clash and not id_conflict:
errors.append(
checks.Error(
"The field '%s' clashes with the field '%s' "
"from model '%s'." % (
f.name, clash.name, clash.model._meta
),
obj=f,
id='models.E006',
)
)
used_fields[f.name] = f
used_fields[f.attname] = f
return errors
@classmethod
def _check_column_name_clashes(cls):
# Store a list of column names which have already been used by other fields.
used_column_names = []
errors = []
for f in cls._meta.local_fields:
_, column_name = f.get_attname_column()
# Ensure the column name is not already in use.
if column_name and column_name in used_column_names:
errors.append(
checks.Error(
"Field '%s' has column name '%s' that is used by "
"another field." % (f.name, column_name),
hint="Specify a 'db_column' for the field.",
obj=cls,
id='models.E007'
)
)
else:
used_column_names.append(column_name)
return errors
@classmethod
def _check_model_name_db_lookup_clashes(cls):
errors = []
model_name = cls.__name__
if model_name.startswith('_') or model_name.endswith('_'):
errors.append(
checks.Error(
"The model name '%s' cannot start or end with an underscore "
"as it collides with the query lookup syntax." % model_name,
obj=cls,
id='models.E023'
)
)
elif LOOKUP_SEP in model_name:
errors.append(
checks.Error(
"The model name '%s' cannot contain double underscores as "
"it collides with the query lookup syntax." % model_name,
obj=cls,
id='models.E024'
)
)
return errors
@classmethod
def _check_property_name_related_field_accessor_clashes(cls):
errors = []
property_names = cls._meta._property_names
related_field_accessors = (
f.get_attname() for f in cls._meta._get_fields(reverse=False)
if f.is_relation and f.related_model is not None
)
for accessor in related_field_accessors:
if accessor in property_names:
errors.append(
checks.Error(
"The property '%s' clashes with a related field "
"accessor." % accessor,
obj=cls,
id='models.E025',
)
)
return errors
@classmethod
def _check_single_primary_key(cls):
errors = []
if sum(1 for f in cls._meta.local_fields if f.primary_key) > 1:
errors.append(
checks.Error(
"The model cannot have more than one field with "
"'primary_key=True'.",
obj=cls,
id='models.E026',
)
)
return errors
@classmethod
def _check_index_together(cls):
"""Check the value of "index_together" option."""
if not isinstance(cls._meta.index_together, (tuple, list)):
return [
checks.Error(
"'index_together' must be a list or tuple.",
obj=cls,
id='models.E008',
)
]
elif any(not isinstance(fields, (tuple, list)) for fields in cls._meta.index_together):
return [
checks.Error(
"All 'index_together' elements must be lists or tuples.",
obj=cls,
id='models.E009',
)
]
else:
errors = []
for fields in cls._meta.index_together:
errors.extend(cls._check_local_fields(fields, "index_together"))
return errors
@classmethod
def _check_unique_together(cls):
"""Check the value of "unique_together" option."""
if not isinstance(cls._meta.unique_together, (tuple, list)):
return [
checks.Error(
"'unique_together' must be a list or tuple.",
obj=cls,
id='models.E010',
)
]
elif any(not isinstance(fields, (tuple, list)) for fields in cls._meta.unique_together):
return [
checks.Error(
"All 'unique_together' elements must be lists or tuples.",
obj=cls,
id='models.E011',
)
]
else:
errors = []
for fields in cls._meta.unique_together:
errors.extend(cls._check_local_fields(fields, "unique_together"))
return errors
@classmethod
def _check_indexes(cls):
"""Check the fields of indexes."""
fields = [field for index in cls._meta.indexes for field, _ in index.fields_orders]
return cls._check_local_fields(fields, 'indexes')
@classmethod
def _check_local_fields(cls, fields, option):
from django.db import models
# In order to avoid hitting the relation tree prematurely, we use our
# own fields_map instead of using get_field()
forward_fields_map = {
field.name: field for field in cls._meta._get_fields(reverse=False)
}
errors = []
for field_name in fields:
try:
field = forward_fields_map[field_name]
except KeyError:
errors.append(
checks.Error(
"'%s' refers to the nonexistent field '%s'." % (
option, field_name,
),
obj=cls,
id='models.E012',
)
)
else:
if isinstance(field.remote_field, models.ManyToManyRel):
errors.append(
checks.Error(
"'%s' refers to a ManyToManyField '%s', but "
"ManyToManyFields are not permitted in '%s'." % (
option, field_name, option,
),
obj=cls,
id='models.E013',
)
)
elif field not in cls._meta.local_fields:
errors.append(
checks.Error(
"'%s' refers to field '%s' which is not local to model '%s'."
% (option, field_name, cls._meta.object_name),
hint="This issue may be caused by multi-table inheritance.",
obj=cls,
id='models.E016',
)
)
return errors
@classmethod
def _check_ordering(cls):
"""
Check "ordering" option -- is it a list of strings and do all fields
exist?
"""
if cls._meta._ordering_clash:
return [
checks.Error(
"'ordering' and 'order_with_respect_to' cannot be used together.",
obj=cls,
id='models.E021',
),
]
if cls._meta.order_with_respect_to or not cls._meta.ordering:
return []
if not isinstance(cls._meta.ordering, (list, tuple)):
return [
checks.Error(
"'ordering' must be a tuple or list (even if you want to order by only one field).",
obj=cls,
id='models.E014',
)
]
errors = []
fields = cls._meta.ordering
# Skip expressions and '?' fields.
fields = (f for f in fields if isinstance(f, str) and f != '?')
# Convert "-field" to "field".
fields = ((f[1:] if f.startswith('-') else f) for f in fields)
# Skip ordering in the format field1__field2 (FIXME: checking
# this format would be nice, but it's a little fiddly).
fields = (f for f in fields if LOOKUP_SEP not in f)
# Skip ordering on pk. This is always a valid order_by field
# but is an alias and therefore won't be found by opts.get_field.
fields = {f for f in fields if f != 'pk'}
# Check for invalid or nonexistent fields in ordering.
invalid_fields = []
# Any field name that is not present in field_names does not exist.
# Also, ordering by m2m fields is not allowed.
opts = cls._meta
valid_fields = set(chain.from_iterable(
(f.name, f.attname) if not (f.auto_created and not f.concrete) else (f.field.related_query_name(),)
for f in chain(opts.fields, opts.related_objects)
))
invalid_fields.extend(fields - valid_fields)
for invalid_field in invalid_fields:
errors.append(
checks.Error(
"'ordering' refers to the nonexistent field '%s'." % invalid_field,
obj=cls,
id='models.E015',
)
)
return errors
@classmethod
def _check_long_column_names(cls):
"""
Check that any auto-generated column names are shorter than the limits
for each database in which the model will be created.
"""
errors = []
allowed_len = None
db_alias = None
# Find the minimum max allowed length among all specified db_aliases.
for db in settings.DATABASES:
# skip databases where the model won't be created
if not router.allow_migrate_model(db, cls):
continue
connection = connections[db]
max_name_length = connection.ops.max_name_length()
if max_name_length is None or connection.features.truncates_names:
continue
else:
if allowed_len is None:
allowed_len = max_name_length
db_alias = db
elif max_name_length < allowed_len:
allowed_len = max_name_length
db_alias = db
if allowed_len is None:
return errors
for f in cls._meta.local_fields:
_, column_name = f.get_attname_column()
# Check if auto-generated name for the field is too long
# for the database.
if f.db_column is None and column_name is not None and len(column_name) > allowed_len:
errors.append(
checks.Error(
'Autogenerated column name too long for field "%s". '
'Maximum length is "%s" for database "%s".'
% (column_name, allowed_len, db_alias),
hint="Set the column name manually using 'db_column'.",
obj=cls,
id='models.E018',
)
)
for f in cls._meta.local_many_to_many:
# Skip nonexistent models.
if isinstance(f.remote_field.through, str):
continue
# Check if auto-generated name for the M2M field is too long
# for the database.
for m2m in f.remote_field.through._meta.local_fields:
_, rel_name = m2m.get_attname_column()
if m2m.db_column is None and rel_name is not None and len(rel_name) > allowed_len:
errors.append(
checks.Error(
'Autogenerated column name too long for M2M field '
'"%s". Maximum length is "%s" for database "%s".'
% (rel_name, allowed_len, db_alias),
hint=(
"Use 'through' to create a separate model for "
"M2M and then set column_name using 'db_column'."
),
obj=cls,
id='models.E019',
)
)
return errors
############################################
# HELPER FUNCTIONS (CURRIED MODEL METHODS) #
############################################
# ORDERING METHODS #########################
def method_set_order(self, ordered_obj, id_list, using=None):
if using is None:
using = DEFAULT_DB_ALIAS
order_wrt = ordered_obj._meta.order_with_respect_to
filter_args = order_wrt.get_forward_related_filter(self)
# FIXME: It would be nice if there was an "update many" version of update
# for situations like this.
with transaction.atomic(using=using, savepoint=False):
for i, j in enumerate(id_list):
ordered_obj.objects.filter(pk=j, **filter_args).update(_order=i)
def method_get_order(self, ordered_obj):
order_wrt = ordered_obj._meta.order_with_respect_to
filter_args = order_wrt.get_forward_related_filter(self)
pk_name = ordered_obj._meta.pk.name
return ordered_obj.objects.filter(**filter_args).values_list(pk_name, flat=True)
def make_foreign_order_accessors(model, related_model):
setattr(
related_model,
'get_%s_order' % model.__name__.lower(),
partialmethod(method_get_order, model)
)
setattr(
related_model,
'set_%s_order' % model.__name__.lower(),
partialmethod(method_set_order, model)
)
########
# MISC #
########
def model_unpickle(model_id):
"""Used to unpickle Model subclasses with deferred fields."""
if isinstance(model_id, tuple):
model = apps.get_model(*model_id)
else:
# Backwards compat - the model was cached directly in earlier versions.
model = model_id
return model.__new__(model)
model_unpickle.__safe_for_unpickle__ = True
|
5027933bd3788d7b98fc16f20f145d78344e5b6cb48314834a36776dbfaad666 | import copy
import inspect
from importlib import import_module
from django.db import router
from django.db.models.query import QuerySet
class BaseManager:
# To retain order, track each time a Manager instance is created.
creation_counter = 0
# Set to True for the 'objects' managers that are automatically created.
auto_created = False
#: If set to True the manager will be serialized into migrations and will
#: thus be available in e.g. RunPython operations.
use_in_migrations = False
def __new__(cls, *args, **kwargs):
# Capture the arguments to make returning them trivial.
obj = super().__new__(cls)
obj._constructor_args = (args, kwargs)
return obj
def __init__(self):
super().__init__()
self._set_creation_counter()
self.model = None
self.name = None
self._db = None
self._hints = {}
def __str__(self):
"""Return "app_label.model_label.manager_name"."""
return '%s.%s' % (self.model._meta.label, self.name)
def deconstruct(self):
"""
Return a 5-tuple of the form (as_manager (True), manager_class,
queryset_class, args, kwargs).
Raise a ValueError if the manager is dynamically generated.
"""
qs_class = self._queryset_class
if getattr(self, '_built_with_as_manager', False):
# using MyQuerySet.as_manager()
return (
True, # as_manager
None, # manager_class
'%s.%s' % (qs_class.__module__, qs_class.__name__), # qs_class
None, # args
None, # kwargs
)
else:
module_name = self.__module__
name = self.__class__.__name__
# Make sure it's actually there and not an inner class
module = import_module(module_name)
if not hasattr(module, name):
raise ValueError(
"Could not find manager %s in %s.\n"
"Please note that you need to inherit from managers you "
"dynamically generated with 'from_queryset()'."
% (name, module_name)
)
return (
False, # as_manager
'%s.%s' % (module_name, name), # manager_class
None, # qs_class
self._constructor_args[0], # args
self._constructor_args[1], # kwargs
)
def check(self, **kwargs):
return []
@classmethod
def _get_queryset_methods(cls, queryset_class):
def create_method(name, method):
def manager_method(self, *args, **kwargs):
return getattr(self.get_queryset(), name)(*args, **kwargs)
manager_method.__name__ = method.__name__
manager_method.__doc__ = method.__doc__
return manager_method
new_methods = {}
for name, method in inspect.getmembers(queryset_class, predicate=inspect.isfunction):
# Only copy missing methods.
if hasattr(cls, name):
continue
# Only copy public methods or methods with the attribute `queryset_only=False`.
queryset_only = getattr(method, 'queryset_only', None)
if queryset_only or (queryset_only is None and name.startswith('_')):
continue
# Copy the method onto the manager.
new_methods[name] = create_method(name, method)
return new_methods
@classmethod
def from_queryset(cls, queryset_class, class_name=None):
if class_name is None:
class_name = '%sFrom%s' % (cls.__name__, queryset_class.__name__)
return type(class_name, (cls,), {
'_queryset_class': queryset_class,
**cls._get_queryset_methods(queryset_class),
})
def contribute_to_class(self, model, name):
self.name = self.name or name
self.model = model
setattr(model, name, ManagerDescriptor(self))
model._meta.add_manager(self)
def _set_creation_counter(self):
"""
Set the creation counter value for this instance and increment the
class-level copy.
"""
self.creation_counter = BaseManager.creation_counter
BaseManager.creation_counter += 1
def db_manager(self, using=None, hints=None):
obj = copy.copy(self)
obj._db = using or self._db
obj._hints = hints or self._hints
return obj
@property
def db(self):
return self._db or router.db_for_read(self.model, **self._hints)
#######################
# PROXIES TO QUERYSET #
#######################
def get_queryset(self):
"""
Return a new QuerySet object. Subclasses can override this method to
customize the behavior of the Manager.
"""
return self._queryset_class(model=self.model, using=self._db, hints=self._hints)
def all(self):
# We can't proxy this method through the `QuerySet` like we do for the
# rest of the `QuerySet` methods. This is because `QuerySet.all()`
# works by creating a "copy" of the current queryset and in making said
# copy, all the cached `prefetch_related` lookups are lost. See the
# implementation of `RelatedManager.get_queryset()` for a better
# understanding of how this comes into play.
return self.get_queryset()
def __eq__(self, other):
return (
isinstance(other, self.__class__) and
self._constructor_args == other._constructor_args
)
def __hash__(self):
return id(self)
class Manager(BaseManager.from_queryset(QuerySet)):
pass
class ManagerDescriptor:
def __init__(self, manager):
self.manager = manager
def __get__(self, instance, cls=None):
if instance is not None:
raise AttributeError("Manager isn't accessible via %s instances" % cls.__name__)
if cls._meta.abstract:
raise AttributeError("Manager isn't available; %s is abstract" % (
cls._meta.object_name,
))
if cls._meta.swapped:
raise AttributeError(
"Manager isn't available; '%s.%s' has been swapped for '%s'" % (
cls._meta.app_label,
cls._meta.object_name,
cls._meta.swapped,
)
)
return cls._meta.managers_map[self.manager.name]
class EmptyManager(Manager):
def __init__(self, model):
super().__init__()
self.model = model
def get_queryset(self):
return super().get_queryset().none()
|
d6643fccf5691e578efc115d114ef5e1ad3d34cbd2991eb9f93dcfdf58613049 | def make_model_tuple(model):
"""
Take a model or a string of the form "app_label.ModelName" and return a
corresponding ("app_label", "modelname") tuple. If a tuple is passed in,
assume it's a valid model tuple already and return it unchanged.
"""
try:
if isinstance(model, tuple):
model_tuple = model
elif isinstance(model, str):
app_label, model_name = model.split(".")
model_tuple = app_label, model_name.lower()
else:
model_tuple = model._meta.app_label, model._meta.model_name
assert len(model_tuple) == 2
return model_tuple
except (ValueError, AssertionError):
raise ValueError(
"Invalid model reference '%s'. String model references "
"must be of the form 'app_label.ModelName'." % model
)
|
29624262e3055ab64fb0b0cf88cd937e4cc2fc7abc81b1185a4bf0faa5c003dc | from functools import partial
from django.db.models.utils import make_model_tuple
from django.dispatch import Signal
class_prepared = Signal(providing_args=["class"])
class ModelSignal(Signal):
"""
Signal subclass that allows the sender to be lazily specified as a string
of the `app_label.ModelName` form.
"""
def _lazy_method(self, method, apps, receiver, sender, **kwargs):
from django.db.models.options import Options
# This partial takes a single optional argument named "sender".
partial_method = partial(method, receiver, **kwargs)
if isinstance(sender, str):
apps = apps or Options.default_apps
apps.lazy_model_operation(partial_method, make_model_tuple(sender))
else:
return partial_method(sender)
def connect(self, receiver, sender=None, weak=True, dispatch_uid=None, apps=None):
self._lazy_method(
super().connect, apps, receiver, sender,
weak=weak, dispatch_uid=dispatch_uid,
)
def disconnect(self, receiver=None, sender=None, dispatch_uid=None, apps=None):
return self._lazy_method(
super().disconnect, apps, receiver, sender, dispatch_uid=dispatch_uid
)
pre_init = ModelSignal(providing_args=["instance", "args", "kwargs"], use_caching=True)
post_init = ModelSignal(providing_args=["instance"], use_caching=True)
pre_save = ModelSignal(providing_args=["instance", "raw", "using", "update_fields"],
use_caching=True)
post_save = ModelSignal(providing_args=["instance", "raw", "created", "using", "update_fields"], use_caching=True)
pre_delete = ModelSignal(providing_args=["instance", "using"], use_caching=True)
post_delete = ModelSignal(providing_args=["instance", "using"], use_caching=True)
m2m_changed = ModelSignal(
providing_args=["action", "instance", "reverse", "model", "pk_set", "using"],
use_caching=True,
)
pre_migrate = Signal(providing_args=["app_config", "verbosity", "interactive", "using", "apps", "plan"])
post_migrate = Signal(providing_args=["app_config", "verbosity", "interactive", "using", "apps", "plan"])
|
9a82f4df251e655b5c4edbda5042ba6d734782cda7ed8aa39ed5eef94c6de8da | """
Various data structures used in query construction.
Factored out from django.db.models.query to avoid making the main module very
large and/or so that they can be used by other modules without getting into
circular import difficulties.
"""
import copy
import functools
import inspect
from collections import namedtuple
from django.db.models.constants import LOOKUP_SEP
from django.utils import tree
# PathInfo is used when converting lookups (fk__somecol). The contents
# describe the relation in Model terms (model Options and Fields for both
# sides of the relation. The join_field is the field backing the relation.
PathInfo = namedtuple('PathInfo', 'from_opts to_opts target_fields join_field m2m direct filtered_relation')
class InvalidQuery(Exception):
"""The query passed to raw() isn't a safe query to use with raw()."""
pass
def subclasses(cls):
yield cls
for subclass in cls.__subclasses__():
yield from subclasses(subclass)
class QueryWrapper:
"""
A type that indicates the contents are an SQL fragment and the associate
parameters. Can be used to pass opaque data to a where-clause, for example.
"""
contains_aggregate = False
def __init__(self, sql, params):
self.data = sql, list(params)
def as_sql(self, compiler=None, connection=None):
return self.data
class Q(tree.Node):
"""
Encapsulate filters as objects that can then be combined logically (using
`&` and `|`).
"""
# Connection types
AND = 'AND'
OR = 'OR'
default = AND
conditional = True
def __init__(self, *args, **kwargs):
connector = kwargs.pop('_connector', None)
negated = kwargs.pop('_negated', False)
super().__init__(children=list(args) + sorted(kwargs.items()), connector=connector, negated=negated)
def _combine(self, other, conn):
if not isinstance(other, Q):
raise TypeError(other)
# If the other Q() is empty, ignore it and just use `self`.
if not other:
return copy.deepcopy(self)
# Or if this Q is empty, ignore it and just use `other`.
elif not self:
return copy.deepcopy(other)
obj = type(self)()
obj.connector = conn
obj.add(self, conn)
obj.add(other, conn)
return obj
def __or__(self, other):
return self._combine(other, self.OR)
def __and__(self, other):
return self._combine(other, self.AND)
def __invert__(self):
obj = type(self)()
obj.add(self, self.AND)
obj.negate()
return obj
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# We must promote any new joins to left outer joins so that when Q is
# used as an expression, rows aren't filtered due to joins.
clause, joins = query._add_q(self, reuse, allow_joins=allow_joins, split_subq=False)
query.promote_joins(joins)
return clause
def deconstruct(self):
path = '%s.%s' % (self.__class__.__module__, self.__class__.__name__)
if path.startswith('django.db.models.query_utils'):
path = path.replace('django.db.models.query_utils', 'django.db.models')
args, kwargs = (), {}
if len(self.children) == 1 and not isinstance(self.children[0], Q):
child = self.children[0]
kwargs = {child[0]: child[1]}
else:
args = tuple(self.children)
if self.connector != self.default:
kwargs = {'_connector': self.connector}
if self.negated:
kwargs['_negated'] = True
return path, args, kwargs
class DeferredAttribute:
"""
A wrapper for a deferred-loading field. When the value is read from this
object the first time, the query is executed.
"""
def __init__(self, field_name):
self.field_name = field_name
def __get__(self, instance, cls=None):
"""
Retrieve and caches the value from the datastore on the first lookup.
Return the cached value.
"""
if instance is None:
return self
data = instance.__dict__
if data.get(self.field_name, self) is self:
# Let's see if the field is part of the parent chain. If so we
# might be able to reuse the already loaded value. Refs #18343.
val = self._check_parent_chain(instance, self.field_name)
if val is None:
instance.refresh_from_db(fields=[self.field_name])
val = getattr(instance, self.field_name)
data[self.field_name] = val
return data[self.field_name]
def _check_parent_chain(self, instance, name):
"""
Check if the field value can be fetched from a parent field already
loaded in the instance. This can be done if the to-be fetched
field is a primary key field.
"""
opts = instance._meta
f = opts.get_field(name)
link_field = opts.get_ancestor_link(f.model)
if f.primary_key and f != link_field:
return getattr(instance, link_field.attname)
return None
class RegisterLookupMixin:
@classmethod
def _get_lookup(cls, lookup_name):
return cls.get_lookups().get(lookup_name, None)
@classmethod
@functools.lru_cache(maxsize=None)
def get_lookups(cls):
class_lookups = [parent.__dict__.get('class_lookups', {}) for parent in inspect.getmro(cls)]
return cls.merge_dicts(class_lookups)
def get_lookup(self, lookup_name):
from django.db.models.lookups import Lookup
found = self._get_lookup(lookup_name)
if found is None and hasattr(self, 'output_field'):
return self.output_field.get_lookup(lookup_name)
if found is not None and not issubclass(found, Lookup):
return None
return found
def get_transform(self, lookup_name):
from django.db.models.lookups import Transform
found = self._get_lookup(lookup_name)
if found is None and hasattr(self, 'output_field'):
return self.output_field.get_transform(lookup_name)
if found is not None and not issubclass(found, Transform):
return None
return found
@staticmethod
def merge_dicts(dicts):
"""
Merge dicts in reverse to preference the order of the original list. e.g.,
merge_dicts([a, b]) will preference the keys in 'a' over those in 'b'.
"""
merged = {}
for d in reversed(dicts):
merged.update(d)
return merged
@classmethod
def _clear_cached_lookups(cls):
for subclass in subclasses(cls):
subclass.get_lookups.cache_clear()
@classmethod
def register_lookup(cls, lookup, lookup_name=None):
if lookup_name is None:
lookup_name = lookup.lookup_name
if 'class_lookups' not in cls.__dict__:
cls.class_lookups = {}
cls.class_lookups[lookup_name] = lookup
cls._clear_cached_lookups()
return lookup
@classmethod
def _unregister_lookup(cls, lookup, lookup_name=None):
"""
Remove given lookup from cls lookups. For use in tests only as it's
not thread-safe.
"""
if lookup_name is None:
lookup_name = lookup.lookup_name
del cls.class_lookups[lookup_name]
def select_related_descend(field, restricted, requested, load_fields, reverse=False):
"""
Return True if this field should be used to descend deeper for
select_related() purposes. Used by both the query construction code
(sql.query.fill_related_selections()) and the model instance creation code
(query.get_klass_info()).
Arguments:
* field - the field to be checked
* restricted - a boolean field, indicating if the field list has been
manually restricted using a requested clause)
* requested - The select_related() dictionary.
* load_fields - the set of fields to be loaded on this model
* reverse - boolean, True if we are checking a reverse select related
"""
if not field.remote_field:
return False
if field.remote_field.parent_link and not reverse:
return False
if restricted:
if reverse and field.related_query_name() not in requested:
return False
if not reverse and field.name not in requested:
return False
if not restricted and field.null:
return False
if load_fields:
if field.attname not in load_fields:
if restricted and field.name in requested:
raise InvalidQuery("Field %s.%s cannot be both deferred"
" and traversed using select_related"
" at the same time." %
(field.model._meta.object_name, field.name))
return True
def refs_expression(lookup_parts, annotations):
"""
Check if the lookup_parts contains references to the given annotations set.
Because the LOOKUP_SEP is contained in the default annotation names, check
each prefix of the lookup_parts for a match.
"""
for n in range(1, len(lookup_parts) + 1):
level_n_lookup = LOOKUP_SEP.join(lookup_parts[0:n])
if level_n_lookup in annotations and annotations[level_n_lookup]:
return annotations[level_n_lookup], lookup_parts[n:]
return False, ()
def check_rel_lookup_compatibility(model, target_opts, field):
"""
Check that self.model is compatible with target_opts. Compatibility
is OK if:
1) model and opts match (where proxy inheritance is removed)
2) model is parent of opts' model or the other way around
"""
def check(opts):
return (
model._meta.concrete_model == opts.concrete_model or
opts.concrete_model in model._meta.get_parent_list() or
model in opts.get_parent_list()
)
# If the field is a primary key, then doing a query against the field's
# model is ok, too. Consider the case:
# class Restaurant(models.Model):
# place = OnetoOneField(Place, primary_key=True):
# Restaurant.objects.filter(pk__in=Restaurant.objects.all()).
# If we didn't have the primary key check, then pk__in (== place__in) would
# give Place's opts as the target opts, but Restaurant isn't compatible
# with that. This logic applies only to primary keys, as when doing __in=qs,
# we are going to turn this into __in=qs.values('pk') later on.
return (
check(target_opts) or
(getattr(field, 'primary_key', False) and check(field.model._meta))
)
class FilteredRelation:
"""Specify custom filtering in the ON clause of SQL joins."""
def __init__(self, relation_name, *, condition=Q()):
if not relation_name:
raise ValueError('relation_name cannot be empty.')
self.relation_name = relation_name
self.alias = None
if not isinstance(condition, Q):
raise ValueError('condition argument must be a Q() instance.')
self.condition = condition
self.path = []
def __eq__(self, other):
return (
isinstance(other, self.__class__) and
self.relation_name == other.relation_name and
self.alias == other.alias and
self.condition == other.condition
)
def clone(self):
clone = FilteredRelation(self.relation_name, condition=self.condition)
clone.alias = self.alias
clone.path = self.path[:]
return clone
def resolve_expression(self, *args, **kwargs):
"""
QuerySet.annotate() only accepts expression-like arguments
(with a resolve_expression() method).
"""
raise NotImplementedError('FilteredRelation.resolve_expression() is unused.')
def as_sql(self, compiler, connection):
# Resolve the condition in Join.filtered_relation.
query = compiler.query
where = query.build_filtered_relation_q(self.condition, reuse=set(self.path))
return compiler.compile(where)
|
06cb452eb1bfaca0472fe219ee2a9763db9228b2fa20e28e8e179705eb426a7d | """
Constants used across the ORM in general.
"""
# Separator used to split filter strings apart.
LOOKUP_SEP = '__'
|
a57a167eebc765bb4f0579f0da94c98a0b716ae2ff2ba751012074301f770c34 | import copy
import datetime
from decimal import Decimal
from django.core.exceptions import EmptyResultSet, FieldError
from django.db import connection
from django.db.models import fields
from django.db.models.query_utils import Q
from django.utils.deconstruct import deconstructible
from django.utils.functional import cached_property
class SQLiteNumericMixin:
"""
Some expressions with output_field=DecimalField() must be cast to
numeric to be properly filtered.
"""
def as_sqlite(self, compiler, connection, **extra_context):
sql, params = self.as_sql(compiler, connection, **extra_context)
try:
if self.output_field.get_internal_type() == 'DecimalField':
sql = 'CAST(%s AS NUMERIC)' % sql
except FieldError:
pass
return sql, params
class Combinable:
"""
Provide the ability to combine one or two objects with
some connector. For example F('foo') + F('bar').
"""
# Arithmetic connectors
ADD = '+'
SUB = '-'
MUL = '*'
DIV = '/'
POW = '^'
# The following is a quoted % operator - it is quoted because it can be
# used in strings that also have parameter substitution.
MOD = '%%'
# Bitwise operators - note that these are generated by .bitand()
# and .bitor(), the '&' and '|' are reserved for boolean operator
# usage.
BITAND = '&'
BITOR = '|'
BITLEFTSHIFT = '<<'
BITRIGHTSHIFT = '>>'
def _combine(self, other, connector, reversed):
if not hasattr(other, 'resolve_expression'):
# everything must be resolvable to an expression
if isinstance(other, datetime.timedelta):
other = DurationValue(other, output_field=fields.DurationField())
else:
other = Value(other)
if reversed:
return CombinedExpression(other, connector, self)
return CombinedExpression(self, connector, other)
#############
# OPERATORS #
#############
def __neg__(self):
return self._combine(-1, self.MUL, False)
def __add__(self, other):
return self._combine(other, self.ADD, False)
def __sub__(self, other):
return self._combine(other, self.SUB, False)
def __mul__(self, other):
return self._combine(other, self.MUL, False)
def __truediv__(self, other):
return self._combine(other, self.DIV, False)
def __mod__(self, other):
return self._combine(other, self.MOD, False)
def __pow__(self, other):
return self._combine(other, self.POW, False)
def __and__(self, other):
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
def bitand(self, other):
return self._combine(other, self.BITAND, False)
def bitleftshift(self, other):
return self._combine(other, self.BITLEFTSHIFT, False)
def bitrightshift(self, other):
return self._combine(other, self.BITRIGHTSHIFT, False)
def __or__(self, other):
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
def bitor(self, other):
return self._combine(other, self.BITOR, False)
def __radd__(self, other):
return self._combine(other, self.ADD, True)
def __rsub__(self, other):
return self._combine(other, self.SUB, True)
def __rmul__(self, other):
return self._combine(other, self.MUL, True)
def __rtruediv__(self, other):
return self._combine(other, self.DIV, True)
def __rmod__(self, other):
return self._combine(other, self.MOD, True)
def __rpow__(self, other):
return self._combine(other, self.POW, True)
def __rand__(self, other):
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
def __ror__(self, other):
raise NotImplementedError(
"Use .bitand() and .bitor() for bitwise logical operations."
)
@deconstructible
class BaseExpression:
"""Base class for all query expressions."""
# aggregate specific fields
is_summary = False
_output_field_resolved_to_none = False
# Can the expression be used in a WHERE clause?
filterable = True
# Can the expression can be used as a source expression in Window?
window_compatible = False
def __init__(self, output_field=None):
if output_field is not None:
self.output_field = output_field
def __getstate__(self):
state = self.__dict__.copy()
state.pop('convert_value', None)
return state
def get_db_converters(self, connection):
return (
[]
if self.convert_value is self._convert_value_noop else
[self.convert_value]
) + self.output_field.get_db_converters(connection)
def get_source_expressions(self):
return []
def set_source_expressions(self, exprs):
assert not exprs
def _parse_expressions(self, *expressions):
return [
arg if hasattr(arg, 'resolve_expression') else (
F(arg) if isinstance(arg, str) else Value(arg)
) for arg in expressions
]
def as_sql(self, compiler, connection):
"""
Responsible for returning a (sql, [params]) tuple to be included
in the current query.
Different backends can provide their own implementation, by
providing an `as_{vendor}` method and patching the Expression:
```
def override_as_sql(self, compiler, connection):
# custom logic
return super().as_sql(compiler, connection)
setattr(Expression, 'as_' + connection.vendor, override_as_sql)
```
Arguments:
* compiler: the query compiler responsible for generating the query.
Must have a compile method, returning a (sql, [params]) tuple.
Calling compiler(value) will return a quoted `value`.
* connection: the database connection used for the current query.
Return: (sql, params)
Where `sql` is a string containing ordered sql parameters to be
replaced with the elements of the list `params`.
"""
raise NotImplementedError("Subclasses must implement as_sql()")
@cached_property
def contains_aggregate(self):
return any(expr and expr.contains_aggregate for expr in self.get_source_expressions())
@cached_property
def contains_over_clause(self):
return any(expr and expr.contains_over_clause for expr in self.get_source_expressions())
@cached_property
def contains_column_references(self):
return any(expr and expr.contains_column_references for expr in self.get_source_expressions())
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
"""
Provide the chance to do any preprocessing or validation before being
added to the query.
Arguments:
* query: the backend query implementation
* allow_joins: boolean allowing or denying use of joins
in this query
* reuse: a set of reusable joins for multijoins
* summarize: a terminal aggregate clause
* for_save: whether this expression about to be used in a save or update
Return: an Expression to be added to the query.
"""
c = self.copy()
c.is_summary = summarize
c.set_source_expressions([
expr.resolve_expression(query, allow_joins, reuse, summarize)
if expr else None
for expr in c.get_source_expressions()
])
return c
def _prepare(self, field):
"""Hook used by Lookup.get_prep_lookup() to do custom preparation."""
return self
@property
def field(self):
return self.output_field
@cached_property
def output_field(self):
"""Return the output type of this expressions."""
output_field = self._resolve_output_field()
if output_field is None:
self._output_field_resolved_to_none = True
raise FieldError('Cannot resolve expression type, unknown output_field')
return output_field
@cached_property
def _output_field_or_none(self):
"""
Return the output field of this expression, or None if
_resolve_output_field() didn't return an output type.
"""
try:
return self.output_field
except FieldError:
if not self._output_field_resolved_to_none:
raise
def _resolve_output_field(self):
"""
Attempt to infer the output type of the expression. If the output
fields of all source fields match then, simply infer the same type
here. This isn't always correct, but it makes sense most of the time.
Consider the difference between `2 + 2` and `2 / 3`. Inferring
the type here is a convenience for the common case. The user should
supply their own output_field with more complex computations.
If a source's output field resolves to None, exclude it from this check.
If all sources are None, then an error is raised higher up the stack in
the output_field property.
"""
sources_iter = (source for source in self.get_source_fields() if source is not None)
for output_field in sources_iter:
if any(not isinstance(output_field, source.__class__) for source in sources_iter):
raise FieldError('Expression contains mixed types. You must set output_field.')
return output_field
@staticmethod
def _convert_value_noop(value, expression, connection):
return value
@cached_property
def convert_value(self):
"""
Expressions provide their own converters because users have the option
of manually specifying the output_field which may be a different type
from the one the database returns.
"""
field = self.output_field
internal_type = field.get_internal_type()
if internal_type == 'FloatField':
return lambda value, expression, connection: None if value is None else float(value)
elif internal_type.endswith('IntegerField'):
return lambda value, expression, connection: None if value is None else int(value)
elif internal_type == 'DecimalField':
return lambda value, expression, connection: None if value is None else Decimal(value)
return self._convert_value_noop
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def get_transform(self, name):
return self.output_field.get_transform(name)
def relabeled_clone(self, change_map):
clone = self.copy()
clone.set_source_expressions([
e.relabeled_clone(change_map) if e is not None else None
for e in self.get_source_expressions()
])
return clone
def copy(self):
return copy.copy(self)
def get_group_by_cols(self):
if not self.contains_aggregate:
return [self]
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def get_source_fields(self):
"""Return the underlying field types used by this aggregate."""
return [e._output_field_or_none for e in self.get_source_expressions()]
def asc(self, **kwargs):
return OrderBy(self, **kwargs)
def desc(self, **kwargs):
return OrderBy(self, descending=True, **kwargs)
def reverse_ordering(self):
return self
def flatten(self):
"""
Recursively yield this expression and all subexpressions, in
depth-first order.
"""
yield self
for expr in self.get_source_expressions():
if expr:
yield from expr.flatten()
def __eq__(self, other):
if self.__class__ != other.__class__:
return False
path, args, kwargs = self.deconstruct()
other_path, other_args, other_kwargs = other.deconstruct()
if (path, args) == (other_path, other_args):
kwargs = kwargs.copy()
other_kwargs = other_kwargs.copy()
output_field = type(kwargs.pop('output_field', None))
other_output_field = type(other_kwargs.pop('output_field', None))
if output_field == other_output_field:
return kwargs == other_kwargs
return False
def __hash__(self):
path, args, kwargs = self.deconstruct()
kwargs = kwargs.copy()
output_field = type(kwargs.pop('output_field', None))
return hash((path, output_field) + args + tuple([
(key, tuple(value)) if isinstance(value, list) else (key, value)
for key, value in kwargs.items()
]))
class Expression(BaseExpression, Combinable):
"""An expression that can be combined with other expressions."""
pass
class CombinedExpression(SQLiteNumericMixin, Expression):
def __init__(self, lhs, connector, rhs, output_field=None):
super().__init__(output_field=output_field)
self.connector = connector
self.lhs = lhs
self.rhs = rhs
def __repr__(self):
return "<{}: {}>".format(self.__class__.__name__, self)
def __str__(self):
return "{} {} {}".format(self.lhs, self.connector, self.rhs)
def get_source_expressions(self):
return [self.lhs, self.rhs]
def set_source_expressions(self, exprs):
self.lhs, self.rhs = exprs
def as_sql(self, compiler, connection):
try:
lhs_output = self.lhs.output_field
except FieldError:
lhs_output = None
try:
rhs_output = self.rhs.output_field
except FieldError:
rhs_output = None
if (not connection.features.has_native_duration_field and
((lhs_output and lhs_output.get_internal_type() == 'DurationField') or
(rhs_output and rhs_output.get_internal_type() == 'DurationField'))):
return DurationExpression(self.lhs, self.connector, self.rhs).as_sql(compiler, connection)
if (lhs_output and rhs_output and self.connector == self.SUB and
lhs_output.get_internal_type() in {'DateField', 'DateTimeField', 'TimeField'} and
lhs_output.get_internal_type() == rhs_output.get_internal_type()):
return TemporalSubtraction(self.lhs, self.rhs).as_sql(compiler, connection)
expressions = []
expression_params = []
sql, params = compiler.compile(self.lhs)
expressions.append(sql)
expression_params.extend(params)
sql, params = compiler.compile(self.rhs)
expressions.append(sql)
expression_params.extend(params)
# order of precedence
expression_wrapper = '(%s)'
sql = connection.ops.combine_expression(self.connector, expressions)
return expression_wrapper % sql, expression_params
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
c.lhs = c.lhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.rhs = c.rhs.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
class DurationExpression(CombinedExpression):
def compile(self, side, compiler, connection):
if not isinstance(side, DurationValue):
try:
output = side.output_field
except FieldError:
pass
else:
if output.get_internal_type() == 'DurationField':
sql, params = compiler.compile(side)
return connection.ops.format_for_duration_arithmetic(sql), params
return compiler.compile(side)
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
expressions = []
expression_params = []
sql, params = self.compile(self.lhs, compiler, connection)
expressions.append(sql)
expression_params.extend(params)
sql, params = self.compile(self.rhs, compiler, connection)
expressions.append(sql)
expression_params.extend(params)
# order of precedence
expression_wrapper = '(%s)'
sql = connection.ops.combine_duration_expression(self.connector, expressions)
return expression_wrapper % sql, expression_params
class TemporalSubtraction(CombinedExpression):
output_field = fields.DurationField()
def __init__(self, lhs, rhs):
super().__init__(lhs, self.SUB, rhs)
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
lhs = compiler.compile(self.lhs, connection)
rhs = compiler.compile(self.rhs, connection)
return connection.ops.subtract_temporals(self.lhs.output_field.get_internal_type(), lhs, rhs)
@deconstructible
class F(Combinable):
"""An object capable of resolving references to existing query objects."""
# Can the expression be used in a WHERE clause?
filterable = True
def __init__(self, name):
"""
Arguments:
* name: the name of the field this expression references
"""
self.name = name
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.name)
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
return query.resolve_ref(self.name, allow_joins, reuse, summarize)
def asc(self, **kwargs):
return OrderBy(self, **kwargs)
def desc(self, **kwargs):
return OrderBy(self, descending=True, **kwargs)
def __eq__(self, other):
return self.__class__ == other.__class__ and self.name == other.name
def __hash__(self):
return hash(self.name)
class ResolvedOuterRef(F):
"""
An object that contains a reference to an outer query.
In this case, the reference to the outer query has been resolved because
the inner query has been used as a subquery.
"""
def as_sql(self, *args, **kwargs):
raise ValueError(
'This queryset contains a reference to an outer query and may '
'only be used in a subquery.'
)
def _prepare(self, output_field=None):
return self
def relabeled_clone(self, relabels):
return self
class OuterRef(F):
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
if isinstance(self.name, self.__class__):
return self.name
return ResolvedOuterRef(self.name)
def _prepare(self, output_field=None):
return self
class Func(SQLiteNumericMixin, Expression):
"""An SQL function call."""
function = None
template = '%(function)s(%(expressions)s)'
arg_joiner = ', '
arity = None # The number of arguments the function accepts.
def __init__(self, *expressions, output_field=None, **extra):
if self.arity is not None and len(expressions) != self.arity:
raise TypeError(
"'%s' takes exactly %s %s (%s given)" % (
self.__class__.__name__,
self.arity,
"argument" if self.arity == 1 else "arguments",
len(expressions),
)
)
super().__init__(output_field=output_field)
self.source_expressions = self._parse_expressions(*expressions)
self.extra = extra
def __repr__(self):
args = self.arg_joiner.join(str(arg) for arg in self.source_expressions)
extra = {**self.extra, **self._get_repr_options()}
if extra:
extra = ', '.join(str(key) + '=' + str(val) for key, val in sorted(extra.items()))
return "{}({}, {})".format(self.__class__.__name__, args, extra)
return "{}({})".format(self.__class__.__name__, args)
def _get_repr_options(self):
"""Return a dict of extra __init__() options to include in the repr."""
return {}
def get_source_expressions(self):
return self.source_expressions
def set_source_expressions(self, exprs):
self.source_expressions = exprs
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
for pos, arg in enumerate(c.source_expressions):
c.source_expressions[pos] = arg.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def as_sql(self, compiler, connection, function=None, template=None, arg_joiner=None, **extra_context):
connection.ops.check_expression_support(self)
sql_parts = []
params = []
for arg in self.source_expressions:
arg_sql, arg_params = compiler.compile(arg)
sql_parts.append(arg_sql)
params.extend(arg_params)
data = {**self.extra, **extra_context}
# Use the first supplied value in this order: the parameter to this
# method, a value supplied in __init__()'s **extra (the value in
# `data`), or the value defined on the class.
if function is not None:
data['function'] = function
else:
data.setdefault('function', self.function)
template = template or data.get('template', self.template)
arg_joiner = arg_joiner or data.get('arg_joiner', self.arg_joiner)
data['expressions'] = data['field'] = arg_joiner.join(sql_parts)
return template % data, params
def copy(self):
copy = super().copy()
copy.source_expressions = self.source_expressions[:]
copy.extra = self.extra.copy()
return copy
class Value(Expression):
"""Represent a wrapped value as a node within an expression."""
def __init__(self, value, output_field=None):
"""
Arguments:
* value: the value this expression represents. The value will be
added into the sql parameter list and properly quoted.
* output_field: an instance of the model field type that this
expression will return, such as IntegerField() or CharField().
"""
super().__init__(output_field=output_field)
self.value = value
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.value)
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
val = self.value
output_field = self._output_field_or_none
if output_field is not None:
if self.for_save:
val = output_field.get_db_prep_save(val, connection=connection)
else:
val = output_field.get_db_prep_value(val, connection=connection)
if hasattr(output_field, 'get_placeholder'):
return output_field.get_placeholder(val, compiler, connection), [val]
if val is None:
# cx_Oracle does not always convert None to the appropriate
# NULL type (like in case expressions using numbers), so we
# use a literal SQL NULL
return 'NULL', []
return '%s', [val]
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = super().resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.for_save = for_save
return c
def get_group_by_cols(self):
return []
class DurationValue(Value):
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
if connection.features.has_native_duration_field:
return super().as_sql(compiler, connection)
return connection.ops.date_interval_sql(self.value), []
class RawSQL(Expression):
def __init__(self, sql, params, output_field=None):
if output_field is None:
output_field = fields.Field()
self.sql, self.params = sql, params
super().__init__(output_field=output_field)
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.sql, self.params)
def as_sql(self, compiler, connection):
return '(%s)' % self.sql, self.params
def get_group_by_cols(self):
return [self]
def __hash__(self):
return hash((self.sql, self.output_field) + tuple(self.params))
class Star(Expression):
def __repr__(self):
return "'*'"
def as_sql(self, compiler, connection):
return '*', []
class Random(Expression):
output_field = fields.FloatField()
def __repr__(self):
return "Random()"
def as_sql(self, compiler, connection):
return connection.ops.random_function_sql(), []
class Col(Expression):
contains_column_references = True
def __init__(self, alias, target, output_field=None):
if output_field is None:
output_field = target
super().__init__(output_field=output_field)
self.alias, self.target = alias, target
def __repr__(self):
return "{}({}, {})".format(
self.__class__.__name__, self.alias, self.target)
def as_sql(self, compiler, connection):
qn = compiler.quote_name_unless_alias
return "%s.%s" % (qn(self.alias), qn(self.target.column)), []
def relabeled_clone(self, relabels):
return self.__class__(relabels.get(self.alias, self.alias), self.target, self.output_field)
def get_group_by_cols(self):
return [self]
def get_db_converters(self, connection):
if self.target == self.output_field:
return self.output_field.get_db_converters(connection)
return (self.output_field.get_db_converters(connection) +
self.target.get_db_converters(connection))
class Ref(Expression):
"""
Reference to column alias of the query. For example, Ref('sum_cost') in
qs.annotate(sum_cost=Sum('cost')) query.
"""
def __init__(self, refs, source):
super().__init__()
self.refs, self.source = refs, source
def __repr__(self):
return "{}({}, {})".format(self.__class__.__name__, self.refs, self.source)
def get_source_expressions(self):
return [self.source]
def set_source_expressions(self, exprs):
self.source, = exprs
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
# The sub-expression `source` has already been resolved, as this is
# just a reference to the name of `source`.
return self
def relabeled_clone(self, relabels):
return self
def as_sql(self, compiler, connection):
return "%s" % connection.ops.quote_name(self.refs), []
def get_group_by_cols(self):
return [self]
class ExpressionList(Func):
"""
An expression containing multiple expressions. Can be used to provide a
list of expressions as an argument to another expression, like an
ordering clause.
"""
template = '%(expressions)s'
def __init__(self, *expressions, **extra):
if not expressions:
raise ValueError('%s requires at least one expression.' % self.__class__.__name__)
super().__init__(*expressions, **extra)
def __str__(self):
return self.arg_joiner.join(str(arg) for arg in self.source_expressions)
class ExpressionWrapper(Expression):
"""
An expression that can wrap another expression so that it can provide
extra context to the inner expression, such as the output_field.
"""
def __init__(self, expression, output_field):
super().__init__(output_field=output_field)
self.expression = expression
def set_source_expressions(self, exprs):
self.expression = exprs[0]
def get_source_expressions(self):
return [self.expression]
def as_sql(self, compiler, connection):
return self.expression.as_sql(compiler, connection)
def __repr__(self):
return "{}({})".format(self.__class__.__name__, self.expression)
class When(Expression):
template = 'WHEN %(condition)s THEN %(result)s'
def __init__(self, condition=None, then=None, **lookups):
if lookups and condition is None:
condition, lookups = Q(**lookups), None
if condition is None or not getattr(condition, 'conditional', False) or lookups:
raise TypeError("__init__() takes either a Q object or lookups as keyword arguments")
if isinstance(condition, Q) and not condition:
raise ValueError("An empty Q() can't be used as a When() condition.")
super().__init__(output_field=None)
self.condition = condition
self.result = self._parse_expressions(then)[0]
def __str__(self):
return "WHEN %r THEN %r" % (self.condition, self.result)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_source_expressions(self):
return [self.condition, self.result]
def set_source_expressions(self, exprs):
self.condition, self.result = exprs
def get_source_fields(self):
# We're only interested in the fields of the result expressions.
return [self.result._output_field_or_none]
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
if hasattr(c.condition, 'resolve_expression'):
c.condition = c.condition.resolve_expression(query, allow_joins, reuse, summarize, False)
c.result = c.result.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def as_sql(self, compiler, connection, template=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = extra_context
sql_params = []
condition_sql, condition_params = compiler.compile(self.condition)
template_params['condition'] = condition_sql
sql_params.extend(condition_params)
result_sql, result_params = compiler.compile(self.result)
template_params['result'] = result_sql
sql_params.extend(result_params)
template = template or self.template
return template % template_params, sql_params
def get_group_by_cols(self):
# This is not a complete expression and cannot be used in GROUP BY.
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
class Case(Expression):
"""
An SQL searched CASE expression:
CASE
WHEN n > 0
THEN 'positive'
WHEN n < 0
THEN 'negative'
ELSE 'zero'
END
"""
template = 'CASE %(cases)s ELSE %(default)s END'
case_joiner = ' '
def __init__(self, *cases, default=None, output_field=None, **extra):
if not all(isinstance(case, When) for case in cases):
raise TypeError("Positional arguments must all be When objects.")
super().__init__(output_field)
self.cases = list(cases)
self.default = self._parse_expressions(default)[0]
self.extra = extra
def __str__(self):
return "CASE %s, ELSE %r" % (', '.join(str(c) for c in self.cases), self.default)
def __repr__(self):
return "<%s: %s>" % (self.__class__.__name__, self)
def get_source_expressions(self):
return self.cases + [self.default]
def set_source_expressions(self, exprs):
self.cases = exprs[:-1]
self.default = exprs[-1]
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
c = self.copy()
c.is_summary = summarize
for pos, case in enumerate(c.cases):
c.cases[pos] = case.resolve_expression(query, allow_joins, reuse, summarize, for_save)
c.default = c.default.resolve_expression(query, allow_joins, reuse, summarize, for_save)
return c
def copy(self):
c = super().copy()
c.cases = c.cases[:]
return c
def as_sql(self, compiler, connection, template=None, case_joiner=None, **extra_context):
connection.ops.check_expression_support(self)
if not self.cases:
return compiler.compile(self.default)
template_params = {**self.extra, **extra_context}
case_parts = []
sql_params = []
for case in self.cases:
try:
case_sql, case_params = compiler.compile(case)
except EmptyResultSet:
continue
case_parts.append(case_sql)
sql_params.extend(case_params)
default_sql, default_params = compiler.compile(self.default)
if not case_parts:
return default_sql, default_params
case_joiner = case_joiner or self.case_joiner
template_params['cases'] = case_joiner.join(case_parts)
template_params['default'] = default_sql
sql_params.extend(default_params)
template = template or template_params.get('template', self.template)
sql = template % template_params
if self._output_field_or_none is not None:
sql = connection.ops.unification_cast_sql(self.output_field) % sql
return sql, sql_params
class Subquery(Expression):
"""
An explicit subquery. It may contain OuterRef() references to the outer
query which will be resolved when it is applied to that query.
"""
template = '(%(subquery)s)'
def __init__(self, queryset, output_field=None, **extra):
self.queryset = queryset
self.extra = extra
super().__init__(output_field)
def _resolve_output_field(self):
if len(self.queryset.query.select) == 1:
return self.queryset.query.select[0].field
return super()._resolve_output_field()
def copy(self):
clone = super().copy()
clone.queryset = clone.queryset.all()
return clone
def resolve_expression(self, query=None, allow_joins=True, reuse=None, summarize=False, for_save=False):
clone = self.copy()
clone.is_summary = summarize
clone.queryset.query.bump_prefix(query)
# Need to recursively resolve these.
def resolve_all(child):
if hasattr(child, 'children'):
[resolve_all(_child) for _child in child.children]
if hasattr(child, 'rhs'):
child.rhs = resolve(child.rhs)
def resolve(child):
if hasattr(child, 'resolve_expression'):
resolved = child.resolve_expression(
query=query, allow_joins=allow_joins, reuse=reuse,
summarize=summarize, for_save=for_save,
)
# Add table alias to the parent query's aliases to prevent
# quoting.
if hasattr(resolved, 'alias') and resolved.alias != resolved.target.model._meta.db_table:
clone.queryset.query.external_aliases.add(resolved.alias)
return resolved
return child
resolve_all(clone.queryset.query.where)
for key, value in clone.queryset.query.annotations.items():
if isinstance(value, Subquery):
clone.queryset.query.annotations[key] = resolve(value)
return clone
def get_source_expressions(self):
return [
x for x in [
getattr(expr, 'lhs', None)
for expr in self.queryset.query.where.children
] if x
]
def relabeled_clone(self, change_map):
clone = self.copy()
clone.queryset.query = clone.queryset.query.relabeled_clone(change_map)
clone.queryset.query.external_aliases.update(
alias for alias in change_map.values()
if alias not in clone.queryset.query.alias_map
)
return clone
def as_sql(self, compiler, connection, template=None, **extra_context):
connection.ops.check_expression_support(self)
template_params = {**self.extra, **extra_context}
template_params['subquery'], sql_params = self.queryset.query.get_compiler(connection=connection).as_sql()
template = template or template_params.get('template', self.template)
sql = template % template_params
return sql, sql_params
def _prepare(self, output_field):
# This method will only be called if this instance is the "rhs" in an
# expression: the wrapping () must be removed (as the expression that
# contains this will provide them). SQLite evaluates ((subquery))
# differently than the other databases.
if self.template == '(%(subquery)s)':
clone = self.copy()
clone.template = '%(subquery)s'
return clone
return self
class Exists(Subquery):
template = 'EXISTS(%(subquery)s)'
output_field = fields.BooleanField()
def __init__(self, *args, negated=False, **kwargs):
self.negated = negated
super().__init__(*args, **kwargs)
def __invert__(self):
return type(self)(self.queryset, negated=(not self.negated), **self.extra)
def resolve_expression(self, query=None, *args, **kwargs):
# As a performance optimization, remove ordering since EXISTS doesn't
# care about it, just whether or not a row matches.
self.queryset = self.queryset.order_by()
return super().resolve_expression(query, *args, **kwargs)
def as_sql(self, compiler, connection, template=None, **extra_context):
sql, params = super().as_sql(compiler, connection, template, **extra_context)
if self.negated:
sql = 'NOT {}'.format(sql)
return sql, params
def as_oracle(self, compiler, connection, template=None, **extra_context):
# Oracle doesn't allow EXISTS() in the SELECT list, so wrap it with a
# CASE WHEN expression. Change the template since the When expression
# requires a left hand side (column) to compare against.
sql, params = self.as_sql(compiler, connection, template, **extra_context)
sql = 'CASE WHEN {} THEN 1 ELSE 0 END'.format(sql)
return sql, params
class OrderBy(BaseExpression):
template = '%(expression)s %(ordering)s'
def __init__(self, expression, descending=False, nulls_first=False, nulls_last=False):
if nulls_first and nulls_last:
raise ValueError('nulls_first and nulls_last are mutually exclusive')
self.nulls_first = nulls_first
self.nulls_last = nulls_last
self.descending = descending
if not hasattr(expression, 'resolve_expression'):
raise ValueError('expression must be an expression type')
self.expression = expression
def __repr__(self):
return "{}({}, descending={})".format(
self.__class__.__name__, self.expression, self.descending)
def set_source_expressions(self, exprs):
self.expression = exprs[0]
def get_source_expressions(self):
return [self.expression]
def as_sql(self, compiler, connection, template=None, **extra_context):
if not template:
if self.nulls_last:
template = '%s NULLS LAST' % self.template
elif self.nulls_first:
template = '%s NULLS FIRST' % self.template
connection.ops.check_expression_support(self)
expression_sql, params = compiler.compile(self.expression)
placeholders = {
'expression': expression_sql,
'ordering': 'DESC' if self.descending else 'ASC',
**extra_context,
}
template = template or self.template
params *= template.count('%(expression)s')
return (template % placeholders).rstrip(), params
def as_sqlite(self, compiler, connection):
template = None
if self.nulls_last:
template = '%(expression)s IS NULL, %(expression)s %(ordering)s'
elif self.nulls_first:
template = '%(expression)s IS NOT NULL, %(expression)s %(ordering)s'
return self.as_sql(compiler, connection, template=template)
def as_mysql(self, compiler, connection):
template = None
if self.nulls_last:
template = 'IF(ISNULL(%(expression)s),1,0), %(expression)s %(ordering)s '
elif self.nulls_first:
template = 'IF(ISNULL(%(expression)s),0,1), %(expression)s %(ordering)s '
return self.as_sql(compiler, connection, template=template)
def get_group_by_cols(self):
cols = []
for source in self.get_source_expressions():
cols.extend(source.get_group_by_cols())
return cols
def reverse_ordering(self):
self.descending = not self.descending
if self.nulls_first or self.nulls_last:
self.nulls_first = not self.nulls_first
self.nulls_last = not self.nulls_last
return self
def asc(self):
self.descending = False
def desc(self):
self.descending = True
class Window(Expression):
template = '%(expression)s OVER (%(window)s)'
# Although the main expression may either be an aggregate or an
# expression with an aggregate function, the GROUP BY that will
# be introduced in the query as a result is not desired.
contains_aggregate = False
contains_over_clause = True
filterable = False
def __init__(self, expression, partition_by=None, order_by=None, frame=None, output_field=None):
self.partition_by = partition_by
self.order_by = order_by
self.frame = frame
if not getattr(expression, 'window_compatible', False):
raise ValueError(
"Expression '%s' isn't compatible with OVER clauses." %
expression.__class__.__name__
)
if self.partition_by is not None:
if not isinstance(self.partition_by, (tuple, list)):
self.partition_by = (self.partition_by,)
self.partition_by = ExpressionList(*self.partition_by)
if self.order_by is not None:
if isinstance(self.order_by, (list, tuple)):
self.order_by = ExpressionList(*self.order_by)
elif not isinstance(self.order_by, BaseExpression):
raise ValueError(
'order_by must be either an Expression or a sequence of '
'expressions.'
)
super().__init__(output_field=output_field)
self.source_expression = self._parse_expressions(expression)[0]
def _resolve_output_field(self):
return self.source_expression.output_field
def get_source_expressions(self):
return [self.source_expression, self.partition_by, self.order_by, self.frame]
def set_source_expressions(self, exprs):
self.source_expression, self.partition_by, self.order_by, self.frame = exprs
def as_sql(self, compiler, connection, function=None, template=None):
connection.ops.check_expression_support(self)
expr_sql, params = compiler.compile(self.source_expression)
window_sql, window_params = [], []
if self.partition_by is not None:
sql_expr, sql_params = self.partition_by.as_sql(
compiler=compiler, connection=connection,
template='PARTITION BY %(expressions)s',
)
window_sql.extend(sql_expr)
window_params.extend(sql_params)
if self.order_by is not None:
window_sql.append(' ORDER BY ')
order_sql, order_params = compiler.compile(self.order_by)
window_sql.extend(''.join(order_sql))
window_params.extend(order_params)
if self.frame:
frame_sql, frame_params = compiler.compile(self.frame)
window_sql.extend(' ' + frame_sql)
window_params.extend(frame_params)
params.extend(window_params)
template = template or self.template
return template % {
'expression': expr_sql,
'window': ''.join(window_sql).strip()
}, params
def __str__(self):
return '{} OVER ({}{}{})'.format(
str(self.source_expression),
'PARTITION BY ' + str(self.partition_by) if self.partition_by else '',
'ORDER BY ' + str(self.order_by) if self.order_by else '',
str(self.frame or ''),
)
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self)
def get_group_by_cols(self):
return []
class WindowFrame(Expression):
"""
Model the frame clause in window expressions. There are two types of frame
clauses which are subclasses, however, all processing and validation (by no
means intended to be complete) is done here. Thus, providing an end for a
frame is optional (the default is UNBOUNDED FOLLOWING, which is the last
row in the frame).
"""
template = '%(frame_type)s BETWEEN %(start)s AND %(end)s'
def __init__(self, start=None, end=None):
self.start = start
self.end = end
def set_source_expressions(self, exprs):
self.start, self.end = exprs
def get_source_expressions(self):
return [Value(self.start), Value(self.end)]
def as_sql(self, compiler, connection):
connection.ops.check_expression_support(self)
start, end = self.window_frame_start_end(connection, self.start.value, self.end.value)
return self.template % {
'frame_type': self.frame_type,
'start': start,
'end': end,
}, []
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self)
def get_group_by_cols(self):
return []
def __str__(self):
if self.start is not None and self.start < 0:
start = '%d %s' % (abs(self.start), connection.ops.PRECEDING)
elif self.start is not None and self.start == 0:
start = connection.ops.CURRENT_ROW
else:
start = connection.ops.UNBOUNDED_PRECEDING
if self.end is not None and self.end > 0:
end = '%d %s' % (self.end, connection.ops.FOLLOWING)
elif self.end is not None and self.end == 0:
end = connection.ops.CURRENT_ROW
else:
end = connection.ops.UNBOUNDED_FOLLOWING
return self.template % {
'frame_type': self.frame_type,
'start': start,
'end': end,
}
def window_frame_start_end(self, connection, start, end):
raise NotImplementedError('Subclasses must implement window_frame_start_end().')
class RowRange(WindowFrame):
frame_type = 'ROWS'
def window_frame_start_end(self, connection, start, end):
return connection.ops.window_frame_rows_start_end(start, end)
class ValueRange(WindowFrame):
frame_type = 'RANGE'
def window_frame_start_end(self, connection, start, end):
return connection.ops.window_frame_range_start_end(start, end)
|
ad0b79910fdfc44f525056504c33f2449e92d11f7e40fbc28e16695cdd6169ff | from collections import Counter, OrderedDict
from operator import attrgetter
from django.db import IntegrityError, connections, transaction
from django.db.models import signals, sql
class ProtectedError(IntegrityError):
def __init__(self, msg, protected_objects):
self.protected_objects = protected_objects
super().__init__(msg, protected_objects)
def CASCADE(collector, field, sub_objs, using):
collector.collect(sub_objs, source=field.remote_field.model,
source_attr=field.name, nullable=field.null)
if field.null and not connections[using].features.can_defer_constraint_checks:
collector.add_field_update(field, None, sub_objs)
def PROTECT(collector, field, sub_objs, using):
raise ProtectedError(
"Cannot delete some instances of model '%s' because they are "
"referenced through a protected foreign key: '%s.%s'" % (
field.remote_field.model.__name__, sub_objs[0].__class__.__name__, field.name
),
sub_objs
)
def SET(value):
if callable(value):
def set_on_delete(collector, field, sub_objs, using):
collector.add_field_update(field, value(), sub_objs)
else:
def set_on_delete(collector, field, sub_objs, using):
collector.add_field_update(field, value, sub_objs)
set_on_delete.deconstruct = lambda: ('django.db.models.SET', (value,), {})
return set_on_delete
def SET_NULL(collector, field, sub_objs, using):
collector.add_field_update(field, None, sub_objs)
def SET_DEFAULT(collector, field, sub_objs, using):
collector.add_field_update(field, field.get_default(), sub_objs)
def DO_NOTHING(collector, field, sub_objs, using):
pass
def get_candidate_relations_to_delete(opts):
# The candidate relations are the ones that come from N-1 and 1-1 relations.
# N-N (i.e., many-to-many) relations aren't candidates for deletion.
return (
f for f in opts.get_fields(include_hidden=True)
if f.auto_created and not f.concrete and (f.one_to_one or f.one_to_many)
)
class Collector:
def __init__(self, using):
self.using = using
# Initially, {model: {instances}}, later values become lists.
self.data = OrderedDict()
self.field_updates = {} # {model: {(field, value): {instances}}}
# fast_deletes is a list of queryset-likes that can be deleted without
# fetching the objects into memory.
self.fast_deletes = []
# Tracks deletion-order dependency for databases without transactions
# or ability to defer constraint checks. Only concrete model classes
# should be included, as the dependencies exist only between actual
# database tables; proxy models are represented here by their concrete
# parent.
self.dependencies = {} # {model: {models}}
def add(self, objs, source=None, nullable=False, reverse_dependency=False):
"""
Add 'objs' to the collection of objects to be deleted. If the call is
the result of a cascade, 'source' should be the model that caused it,
and 'nullable' should be set to True if the relation can be null.
Return a list of all objects that were not already collected.
"""
if not objs:
return []
new_objs = []
model = objs[0].__class__
instances = self.data.setdefault(model, set())
for obj in objs:
if obj not in instances:
new_objs.append(obj)
instances.update(new_objs)
# Nullable relationships can be ignored -- they are nulled out before
# deleting, and therefore do not affect the order in which objects have
# to be deleted.
if source is not None and not nullable:
if reverse_dependency:
source, model = model, source
self.dependencies.setdefault(
source._meta.concrete_model, set()).add(model._meta.concrete_model)
return new_objs
def add_field_update(self, field, value, objs):
"""
Schedule a field update. 'objs' must be a homogeneous iterable
collection of model instances (e.g. a QuerySet).
"""
if not objs:
return
model = objs[0].__class__
self.field_updates.setdefault(
model, {}).setdefault(
(field, value), set()).update(objs)
def can_fast_delete(self, objs, from_field=None):
"""
Determine if the objects in the given queryset-like can be
fast-deleted. This can be done if there are no cascades, no
parents and no signal listeners for the object class.
The 'from_field' tells where we are coming from - we need this to
determine if the objects are in fact to be deleted. Allow also
skipping parent -> child -> parent chain preventing fast delete of
the child.
"""
if from_field and from_field.remote_field.on_delete is not CASCADE:
return False
if not (hasattr(objs, 'model') and hasattr(objs, '_raw_delete')):
return False
model = objs.model
if (signals.pre_delete.has_listeners(model) or
signals.post_delete.has_listeners(model) or
signals.m2m_changed.has_listeners(model)):
return False
# The use of from_field comes from the need to avoid cascade back to
# parent when parent delete is cascading to child.
opts = model._meta
return (
all(link == from_field for link in opts.concrete_model._meta.parents.values()) and
# Foreign keys pointing to this model.
all(
related.field.remote_field.on_delete is DO_NOTHING
for related in get_candidate_relations_to_delete(opts)
) and (
# Something like generic foreign key.
not any(hasattr(field, 'bulk_related_objects') for field in model._meta.private_fields)
)
)
def get_del_batches(self, objs, field):
"""
Return the objs in suitably sized batches for the used connection.
"""
conn_batch_size = max(
connections[self.using].ops.bulk_batch_size([field.name], objs), 1)
if len(objs) > conn_batch_size:
return [objs[i:i + conn_batch_size]
for i in range(0, len(objs), conn_batch_size)]
else:
return [objs]
def collect(self, objs, source=None, nullable=False, collect_related=True,
source_attr=None, reverse_dependency=False, keep_parents=False):
"""
Add 'objs' to the collection of objects to be deleted as well as all
parent instances. 'objs' must be a homogeneous iterable collection of
model instances (e.g. a QuerySet). If 'collect_related' is True,
related objects will be handled by their respective on_delete handler.
If the call is the result of a cascade, 'source' should be the model
that caused it and 'nullable' should be set to True, if the relation
can be null.
If 'reverse_dependency' is True, 'source' will be deleted before the
current model, rather than after. (Needed for cascading to parent
models, the one case in which the cascade follows the forwards
direction of an FK rather than the reverse direction.)
If 'keep_parents' is True, data of parent model's will be not deleted.
"""
if self.can_fast_delete(objs):
self.fast_deletes.append(objs)
return
new_objs = self.add(objs, source, nullable,
reverse_dependency=reverse_dependency)
if not new_objs:
return
model = new_objs[0].__class__
if not keep_parents:
# Recursively collect concrete model's parent models, but not their
# related objects. These will be found by meta.get_fields()
concrete_model = model._meta.concrete_model
for ptr in concrete_model._meta.parents.values():
if ptr:
parent_objs = [getattr(obj, ptr.name) for obj in new_objs]
self.collect(parent_objs, source=model,
source_attr=ptr.remote_field.related_name,
collect_related=False,
reverse_dependency=True)
if collect_related:
parents = model._meta.parents
for related in get_candidate_relations_to_delete(model._meta):
# Preserve parent reverse relationships if keep_parents=True.
if keep_parents and related.model in parents:
continue
field = related.field
if field.remote_field.on_delete == DO_NOTHING:
continue
batches = self.get_del_batches(new_objs, field)
for batch in batches:
sub_objs = self.related_objects(related, batch)
if self.can_fast_delete(sub_objs, from_field=field):
self.fast_deletes.append(sub_objs)
elif sub_objs:
field.remote_field.on_delete(self, field, sub_objs, self.using)
for field in model._meta.private_fields:
if hasattr(field, 'bulk_related_objects'):
# It's something like generic foreign key.
sub_objs = field.bulk_related_objects(new_objs, self.using)
self.collect(sub_objs, source=model, nullable=True)
def related_objects(self, related, objs):
"""
Get a QuerySet of objects related to `objs` via the relation `related`.
"""
return related.related_model._base_manager.using(self.using).filter(
**{"%s__in" % related.field.name: objs}
)
def instances_with_model(self):
for model, instances in self.data.items():
for obj in instances:
yield model, obj
def sort(self):
sorted_models = []
concrete_models = set()
models = list(self.data)
while len(sorted_models) < len(models):
found = False
for model in models:
if model in sorted_models:
continue
dependencies = self.dependencies.get(model._meta.concrete_model)
if not (dependencies and dependencies.difference(concrete_models)):
sorted_models.append(model)
concrete_models.add(model._meta.concrete_model)
found = True
if not found:
return
self.data = OrderedDict((model, self.data[model])
for model in sorted_models)
def delete(self):
# sort instance collections
for model, instances in self.data.items():
self.data[model] = sorted(instances, key=attrgetter("pk"))
# if possible, bring the models in an order suitable for databases that
# don't support transactions or cannot defer constraint checks until the
# end of a transaction.
self.sort()
# number of objects deleted for each model label
deleted_counter = Counter()
with transaction.atomic(using=self.using, savepoint=False):
# send pre_delete signals
for model, obj in self.instances_with_model():
if not model._meta.auto_created:
signals.pre_delete.send(
sender=model, instance=obj, using=self.using
)
# fast deletes
for qs in self.fast_deletes:
count = qs._raw_delete(using=self.using)
deleted_counter[qs.model._meta.label] += count
# update fields
for model, instances_for_fieldvalues in self.field_updates.items():
for (field, value), instances in instances_for_fieldvalues.items():
query = sql.UpdateQuery(model)
query.update_batch([obj.pk for obj in instances],
{field.name: value}, self.using)
# reverse instance collections
for instances in self.data.values():
instances.reverse()
# delete instances
for model, instances in self.data.items():
query = sql.DeleteQuery(model)
pk_list = [obj.pk for obj in instances]
count = query.delete_batch(pk_list, self.using)
deleted_counter[model._meta.label] += count
if not model._meta.auto_created:
for obj in instances:
signals.post_delete.send(
sender=model, instance=obj, using=self.using
)
# update collected instances
for instances_for_fieldvalues in self.field_updates.values():
for (field, value), instances in instances_for_fieldvalues.items():
for obj in instances:
setattr(obj, field.attname, value)
for model, instances in self.data.items():
for instance in instances:
setattr(instance, model._meta.pk.attname, None)
return sum(deleted_counter.values()), dict(deleted_counter)
|
d7ab4e4bbdbf1bb6a64d3e767f9cc32319e56e5aabbb12cc279d16a8053b6137 | import itertools
import math
from copy import copy
from django.core.exceptions import EmptyResultSet
from django.db.models.expressions import Func, Value
from django.db.models.fields import DateTimeField, Field, IntegerField
from django.db.models.query_utils import RegisterLookupMixin
from django.utils.datastructures import OrderedSet
from django.utils.functional import cached_property
class Lookup:
lookup_name = None
prepare_rhs = True
can_use_none_as_rhs = False
def __init__(self, lhs, rhs):
self.lhs, self.rhs = lhs, rhs
self.rhs = self.get_prep_lookup()
if hasattr(self.lhs, 'get_bilateral_transforms'):
bilateral_transforms = self.lhs.get_bilateral_transforms()
else:
bilateral_transforms = []
if bilateral_transforms:
# Warn the user as soon as possible if they are trying to apply
# a bilateral transformation on a nested QuerySet: that won't work.
from django.db.models.sql.query import Query # avoid circular import
if isinstance(rhs, Query):
raise NotImplementedError("Bilateral transformations on nested querysets are not implemented.")
self.bilateral_transforms = bilateral_transforms
def apply_bilateral_transforms(self, value):
for transform in self.bilateral_transforms:
value = transform(value)
return value
def batch_process_rhs(self, compiler, connection, rhs=None):
if rhs is None:
rhs = self.rhs
if self.bilateral_transforms:
sqls, sqls_params = [], []
for p in rhs:
value = Value(p, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
sql, sql_params = compiler.compile(value)
sqls.append(sql)
sqls_params.extend(sql_params)
else:
_, params = self.get_db_prep_lookup(rhs, connection)
sqls, sqls_params = ['%s'] * len(params), params
return sqls, sqls_params
def get_source_expressions(self):
if self.rhs_is_direct_value():
return [self.lhs]
return [self.lhs, self.rhs]
def set_source_expressions(self, new_exprs):
if len(new_exprs) == 1:
self.lhs = new_exprs[0]
else:
self.lhs, self.rhs = new_exprs
def get_prep_lookup(self):
if hasattr(self.rhs, '_prepare'):
return self.rhs._prepare(self.lhs.output_field)
if self.prepare_rhs and hasattr(self.lhs.output_field, 'get_prep_value'):
return self.lhs.output_field.get_prep_value(self.rhs)
return self.rhs
def get_db_prep_lookup(self, value, connection):
return ('%s', [value])
def process_lhs(self, compiler, connection, lhs=None):
lhs = lhs or self.lhs
if hasattr(lhs, 'resolve_expression'):
lhs = lhs.resolve_expression(compiler.query)
return compiler.compile(lhs)
def process_rhs(self, compiler, connection):
value = self.rhs
if self.bilateral_transforms:
if self.rhs_is_direct_value():
# Do not call get_db_prep_lookup here as the value will be
# transformed before being used for lookup
value = Value(value, output_field=self.lhs.output_field)
value = self.apply_bilateral_transforms(value)
value = value.resolve_expression(compiler.query)
if hasattr(value, 'as_sql'):
sql, params = compiler.compile(value)
return '(' + sql + ')', params
else:
return self.get_db_prep_lookup(value, connection)
def rhs_is_direct_value(self):
return not hasattr(self.rhs, 'as_sql')
def relabeled_clone(self, relabels):
new = copy(self)
new.lhs = new.lhs.relabeled_clone(relabels)
if hasattr(new.rhs, 'relabeled_clone'):
new.rhs = new.rhs.relabeled_clone(relabels)
return new
def get_group_by_cols(self):
cols = self.lhs.get_group_by_cols()
if hasattr(self.rhs, 'get_group_by_cols'):
cols.extend(self.rhs.get_group_by_cols())
return cols
def as_sql(self, compiler, connection):
raise NotImplementedError
@cached_property
def contains_aggregate(self):
return self.lhs.contains_aggregate or getattr(self.rhs, 'contains_aggregate', False)
@cached_property
def contains_over_clause(self):
return self.lhs.contains_over_clause or getattr(self.rhs, 'contains_over_clause', False)
@property
def is_summary(self):
return self.lhs.is_summary or getattr(self.rhs, 'is_summary', False)
class Transform(RegisterLookupMixin, Func):
"""
RegisterLookupMixin() is first so that get_lookup() and get_transform()
first examine self and then check output_field.
"""
bilateral = False
arity = 1
@property
def lhs(self):
return self.get_source_expressions()[0]
def get_bilateral_transforms(self):
if hasattr(self.lhs, 'get_bilateral_transforms'):
bilateral_transforms = self.lhs.get_bilateral_transforms()
else:
bilateral_transforms = []
if self.bilateral:
bilateral_transforms.append(self.__class__)
return bilateral_transforms
class BuiltinLookup(Lookup):
def process_lhs(self, compiler, connection, lhs=None):
lhs_sql, params = super().process_lhs(compiler, connection, lhs)
field_internal_type = self.lhs.output_field.get_internal_type()
db_type = self.lhs.output_field.db_type(connection=connection)
lhs_sql = connection.ops.field_cast_sql(
db_type, field_internal_type) % lhs_sql
lhs_sql = connection.ops.lookup_cast(self.lookup_name, field_internal_type) % lhs_sql
return lhs_sql, list(params)
def as_sql(self, compiler, connection):
lhs_sql, params = self.process_lhs(compiler, connection)
rhs_sql, rhs_params = self.process_rhs(compiler, connection)
params.extend(rhs_params)
rhs_sql = self.get_rhs_op(connection, rhs_sql)
return '%s %s' % (lhs_sql, rhs_sql), params
def get_rhs_op(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
class FieldGetDbPrepValueMixin:
"""
Some lookups require Field.get_db_prep_value() to be called on their
inputs.
"""
get_db_prep_lookup_value_is_iterable = False
def get_db_prep_lookup(self, value, connection):
# For relational fields, use the output_field of the 'field' attribute.
field = getattr(self.lhs.output_field, 'field', None)
get_db_prep_value = getattr(field, 'get_db_prep_value', None) or self.lhs.output_field.get_db_prep_value
return (
'%s',
[get_db_prep_value(v, connection, prepared=True) for v in value]
if self.get_db_prep_lookup_value_is_iterable else
[get_db_prep_value(value, connection, prepared=True)]
)
class FieldGetDbPrepValueIterableMixin(FieldGetDbPrepValueMixin):
"""
Some lookups require Field.get_db_prep_value() to be called on each value
in an iterable.
"""
get_db_prep_lookup_value_is_iterable = True
def get_prep_lookup(self):
prepared_values = []
if hasattr(self.rhs, '_prepare'):
# A subquery is like an iterable but its items shouldn't be
# prepared independently.
return self.rhs._prepare(self.lhs.output_field)
for rhs_value in self.rhs:
if hasattr(rhs_value, 'resolve_expression'):
# An expression will be handled by the database but can coexist
# alongside real values.
pass
elif self.prepare_rhs and hasattr(self.lhs.output_field, 'get_prep_value'):
rhs_value = self.lhs.output_field.get_prep_value(rhs_value)
prepared_values.append(rhs_value)
return prepared_values
def process_rhs(self, compiler, connection):
if self.rhs_is_direct_value():
# rhs should be an iterable of values. Use batch_process_rhs()
# to prepare/transform those values.
return self.batch_process_rhs(compiler, connection)
else:
return super().process_rhs(compiler, connection)
def resolve_expression_parameter(self, compiler, connection, sql, param):
params = [param]
if hasattr(param, 'resolve_expression'):
param = param.resolve_expression(compiler.query)
if hasattr(param, 'as_sql'):
sql, params = param.as_sql(compiler, connection)
return sql, params
def batch_process_rhs(self, compiler, connection, rhs=None):
pre_processed = super().batch_process_rhs(compiler, connection, rhs)
# The params list may contain expressions which compile to a
# sql/param pair. Zip them to get sql and param pairs that refer to the
# same argument and attempt to replace them with the result of
# compiling the param step.
sql, params = zip(*(
self.resolve_expression_parameter(compiler, connection, sql, param)
for sql, param in zip(*pre_processed)
))
params = itertools.chain.from_iterable(params)
return sql, tuple(params)
@Field.register_lookup
class Exact(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'exact'
def process_rhs(self, compiler, connection):
from django.db.models.sql.query import Query
if isinstance(self.rhs, Query):
if self.rhs.has_limit_one():
# The subquery must select only the pk.
self.rhs.clear_select_clause()
self.rhs.add_fields(['pk'])
else:
raise ValueError(
'The QuerySet value for an exact lookup must be limited to '
'one result using slicing.'
)
return super().process_rhs(compiler, connection)
@Field.register_lookup
class IExact(BuiltinLookup):
lookup_name = 'iexact'
prepare_rhs = False
def process_rhs(self, qn, connection):
rhs, params = super().process_rhs(qn, connection)
if params:
params[0] = connection.ops.prep_for_iexact_query(params[0])
return rhs, params
@Field.register_lookup
class GreaterThan(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'gt'
@Field.register_lookup
class GreaterThanOrEqual(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'gte'
@Field.register_lookup
class LessThan(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'lt'
@Field.register_lookup
class LessThanOrEqual(FieldGetDbPrepValueMixin, BuiltinLookup):
lookup_name = 'lte'
class IntegerFieldFloatRounding:
"""
Allow floats to work as query values for IntegerField. Without this, the
decimal portion of the float would always be discarded.
"""
def get_prep_lookup(self):
if isinstance(self.rhs, float):
self.rhs = math.ceil(self.rhs)
return super().get_prep_lookup()
@IntegerField.register_lookup
class IntegerGreaterThanOrEqual(IntegerFieldFloatRounding, GreaterThanOrEqual):
pass
@IntegerField.register_lookup
class IntegerLessThan(IntegerFieldFloatRounding, LessThan):
pass
@Field.register_lookup
class In(FieldGetDbPrepValueIterableMixin, BuiltinLookup):
lookup_name = 'in'
def process_rhs(self, compiler, connection):
db_rhs = getattr(self.rhs, '_db', None)
if db_rhs is not None and db_rhs != connection.alias:
raise ValueError(
"Subqueries aren't allowed across different databases. Force "
"the inner query to be evaluated using `list(inner_query)`."
)
if self.rhs_is_direct_value():
try:
rhs = OrderedSet(self.rhs)
except TypeError: # Unhashable items in self.rhs
rhs = self.rhs
if not rhs:
raise EmptyResultSet
# rhs should be an iterable; use batch_process_rhs() to
# prepare/transform those values.
sqls, sqls_params = self.batch_process_rhs(compiler, connection, rhs)
placeholder = '(' + ', '.join(sqls) + ')'
return (placeholder, sqls_params)
else:
if not getattr(self.rhs, 'has_select_fields', True):
self.rhs.clear_select_clause()
self.rhs.add_fields(['pk'])
return super().process_rhs(compiler, connection)
def get_rhs_op(self, connection, rhs):
return 'IN %s' % rhs
def as_sql(self, compiler, connection):
max_in_list_size = connection.ops.max_in_list_size()
if self.rhs_is_direct_value() and max_in_list_size and len(self.rhs) > max_in_list_size:
return self.split_parameter_list_as_sql(compiler, connection)
return super().as_sql(compiler, connection)
def split_parameter_list_as_sql(self, compiler, connection):
# This is a special case for databases which limit the number of
# elements which can appear in an 'IN' clause.
max_in_list_size = connection.ops.max_in_list_size()
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.batch_process_rhs(compiler, connection)
in_clause_elements = ['(']
params = []
for offset in range(0, len(rhs_params), max_in_list_size):
if offset > 0:
in_clause_elements.append(' OR ')
in_clause_elements.append('%s IN (' % lhs)
params.extend(lhs_params)
sqls = rhs[offset: offset + max_in_list_size]
sqls_params = rhs_params[offset: offset + max_in_list_size]
param_group = ', '.join(sqls)
in_clause_elements.append(param_group)
in_clause_elements.append(')')
params.extend(sqls_params)
in_clause_elements.append(')')
return ''.join(in_clause_elements), params
class PatternLookup(BuiltinLookup):
param_pattern = '%%%s%%'
prepare_rhs = False
def get_rhs_op(self, connection, rhs):
# Assume we are in startswith. We need to produce SQL like:
# col LIKE %s, ['thevalue%']
# For python values we can (and should) do that directly in Python,
# but if the value is for example reference to other column, then
# we need to add the % pattern match to the lookup by something like
# col LIKE othercol || '%%'
# So, for Python values we don't need any special pattern, but for
# SQL reference values or SQL transformations we need the correct
# pattern added.
if hasattr(self.rhs, 'as_sql') or self.bilateral_transforms:
pattern = connection.pattern_ops[self.lookup_name].format(connection.pattern_esc)
return pattern.format(rhs)
else:
return super().get_rhs_op(connection, rhs)
def process_rhs(self, qn, connection):
rhs, params = super().process_rhs(qn, connection)
if self.rhs_is_direct_value() and params and not self.bilateral_transforms:
params[0] = self.param_pattern % connection.ops.prep_for_like_query(params[0])
return rhs, params
@Field.register_lookup
class Contains(PatternLookup):
lookup_name = 'contains'
@Field.register_lookup
class IContains(Contains):
lookup_name = 'icontains'
@Field.register_lookup
class StartsWith(PatternLookup):
lookup_name = 'startswith'
param_pattern = '%s%%'
@Field.register_lookup
class IStartsWith(StartsWith):
lookup_name = 'istartswith'
@Field.register_lookup
class EndsWith(PatternLookup):
lookup_name = 'endswith'
param_pattern = '%%%s'
@Field.register_lookup
class IEndsWith(EndsWith):
lookup_name = 'iendswith'
@Field.register_lookup
class Range(FieldGetDbPrepValueIterableMixin, BuiltinLookup):
lookup_name = 'range'
def get_rhs_op(self, connection, rhs):
return "BETWEEN %s AND %s" % (rhs[0], rhs[1])
@Field.register_lookup
class IsNull(BuiltinLookup):
lookup_name = 'isnull'
prepare_rhs = False
def as_sql(self, compiler, connection):
sql, params = compiler.compile(self.lhs)
if self.rhs:
return "%s IS NULL" % sql, params
else:
return "%s IS NOT NULL" % sql, params
@Field.register_lookup
class Regex(BuiltinLookup):
lookup_name = 'regex'
prepare_rhs = False
def as_sql(self, compiler, connection):
if self.lookup_name in connection.operators:
return super().as_sql(compiler, connection)
else:
lhs, lhs_params = self.process_lhs(compiler, connection)
rhs, rhs_params = self.process_rhs(compiler, connection)
sql_template = connection.ops.regex_lookup(self.lookup_name)
return sql_template % (lhs, rhs), lhs_params + rhs_params
@Field.register_lookup
class IRegex(Regex):
lookup_name = 'iregex'
class YearLookup(Lookup):
def year_lookup_bounds(self, connection, year):
output_field = self.lhs.lhs.output_field
if isinstance(output_field, DateTimeField):
bounds = connection.ops.year_lookup_bounds_for_datetime_field(year)
else:
bounds = connection.ops.year_lookup_bounds_for_date_field(year)
return bounds
class YearComparisonLookup(YearLookup):
def as_sql(self, compiler, connection):
# We will need to skip the extract part and instead go
# directly with the originating field, that is self.lhs.lhs.
lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
rhs_sql, rhs_params = self.process_rhs(compiler, connection)
rhs_sql = self.get_rhs_op(connection, rhs_sql)
start, finish = self.year_lookup_bounds(connection, rhs_params[0])
params.append(self.get_bound(start, finish))
return '%s %s' % (lhs_sql, rhs_sql), params
def get_rhs_op(self, connection, rhs):
return connection.operators[self.lookup_name] % rhs
def get_bound(self, start, finish):
raise NotImplementedError(
'subclasses of YearComparisonLookup must provide a get_bound() method'
)
class YearExact(YearLookup, Exact):
lookup_name = 'exact'
def as_sql(self, compiler, connection):
# We will need to skip the extract part and instead go
# directly with the originating field, that is self.lhs.lhs.
lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
rhs_sql, rhs_params = self.process_rhs(compiler, connection)
try:
# Check that rhs_params[0] exists (IndexError),
# it isn't None (TypeError), and is a number (ValueError)
int(rhs_params[0])
except (IndexError, TypeError, ValueError):
# Can't determine the bounds before executing the query, so skip
# optimizations by falling back to a standard exact comparison.
return super().as_sql(compiler, connection)
bounds = self.year_lookup_bounds(connection, rhs_params[0])
params.extend(bounds)
return '%s BETWEEN %%s AND %%s' % lhs_sql, params
class YearGt(YearComparisonLookup):
lookup_name = 'gt'
def get_bound(self, start, finish):
return finish
class YearGte(YearComparisonLookup):
lookup_name = 'gte'
def get_bound(self, start, finish):
return start
class YearLt(YearComparisonLookup):
lookup_name = 'lt'
def get_bound(self, start, finish):
return start
class YearLte(YearComparisonLookup):
lookup_name = 'lte'
def get_bound(self, start, finish):
return finish
|
74183ac52369c87dd874722777969f028ea853f512a6ff36f259eb83bf2d9ae8 | """
Helpers to manipulate deferred DDL statements that might need to be adjusted or
discarded within when executing a migration.
"""
class Reference:
"""Base class that defines the reference interface."""
def references_table(self, table):
"""
Return whether or not this instance references the specified table.
"""
return False
def references_column(self, table, column):
"""
Return whether or not this instance references the specified column.
"""
return False
def rename_table_references(self, old_table, new_table):
"""
Rename all references to the old_name to the new_table.
"""
pass
def rename_column_references(self, table, old_column, new_column):
"""
Rename all references to the old_column to the new_column.
"""
pass
def __repr__(self):
return '<%s %r>' % (self.__class__.__name__, str(self))
def __str__(self):
raise NotImplementedError('Subclasses must define how they should be converted to string.')
class Table(Reference):
"""Hold a reference to a table."""
def __init__(self, table, quote_name):
self.table = table
self.quote_name = quote_name
def references_table(self, table):
return self.table == table
def rename_table_references(self, old_table, new_table):
if self.table == old_table:
self.table = new_table
def __str__(self):
return self.quote_name(self.table)
class TableColumns(Table):
"""Base class for references to multiple columns of a table."""
def __init__(self, table, columns):
self.table = table
self.columns = columns
def references_column(self, table, column):
return self.table == table and column in self.columns
def rename_column_references(self, table, old_column, new_column):
if self.table == table:
for index, column in enumerate(self.columns):
if column == old_column:
self.columns[index] = new_column
class Columns(TableColumns):
"""Hold a reference to one or many columns."""
def __init__(self, table, columns, quote_name, col_suffixes=()):
self.quote_name = quote_name
self.col_suffixes = col_suffixes
super().__init__(table, columns)
def __str__(self):
def col_str(column, idx):
try:
return self.quote_name(column) + self.col_suffixes[idx]
except IndexError:
return self.quote_name(column)
return ', '.join(col_str(column, idx) for idx, column in enumerate(self.columns))
class IndexName(TableColumns):
"""Hold a reference to an index name."""
def __init__(self, table, columns, suffix, create_index_name):
self.suffix = suffix
self.create_index_name = create_index_name
super().__init__(table, columns)
def __str__(self):
return self.create_index_name(self.table, self.columns, self.suffix)
class ForeignKeyName(TableColumns):
"""Hold a reference to a foreign key name."""
def __init__(self, from_table, from_columns, to_table, to_columns, suffix_template, create_fk_name):
self.to_reference = TableColumns(to_table, to_columns)
self.suffix_template = suffix_template
self.create_fk_name = create_fk_name
super().__init__(from_table, from_columns,)
def references_table(self, table):
return super().references_table(table) or self.to_reference.references_table(table)
def references_column(self, table, column):
return (
super().references_column(table, column) or
self.to_reference.references_column(table, column)
)
def rename_table_references(self, old_table, new_table):
super().rename_table_references(old_table, new_table)
self.to_reference.rename_table_references(old_table, new_table)
def rename_column_references(self, table, old_column, new_column):
super().rename_column_references(table, old_column, new_column)
self.to_reference.rename_column_references(table, old_column, new_column)
def __str__(self):
suffix = self.suffix_template % {
'to_table': self.to_reference.table,
'to_column': self.to_reference.columns[0],
}
return self.create_fk_name(self.table, self.columns, suffix)
class Statement(Reference):
"""
Statement template and formatting parameters container.
Allows keeping a reference to a statement without interpolating identifiers
that might have to be adjusted if they're referencing a table or column
that is removed
"""
def __init__(self, template, **parts):
self.template = template
self.parts = parts
def references_table(self, table):
return any(
hasattr(part, 'references_table') and part.references_table(table)
for part in self.parts.values()
)
def references_column(self, table, column):
return any(
hasattr(part, 'references_column') and part.references_column(table, column)
for part in self.parts.values()
)
def rename_table_references(self, old_table, new_table):
for part in self.parts.values():
if hasattr(part, 'rename_table_references'):
part.rename_table_references(old_table, new_table)
def rename_column_references(self, table, old_column, new_column):
for part in self.parts.values():
if hasattr(part, 'rename_column_references'):
part.rename_column_references(table, old_column, new_column)
def __str__(self):
return self.template % self.parts
|
db3d1c55a230406975b637f63b9d0da1062e83613ce81273d575ac89da6a625c | import datetime
import decimal
import functools
import hashlib
import logging
from time import time
from django.conf import settings
from django.db.utils import NotSupportedError
from django.utils.encoding import force_bytes
from django.utils.timezone import utc
logger = logging.getLogger('django.db.backends')
class CursorWrapper:
def __init__(self, cursor, db):
self.cursor = cursor
self.db = db
WRAP_ERROR_ATTRS = frozenset(['fetchone', 'fetchmany', 'fetchall', 'nextset'])
def __getattr__(self, attr):
cursor_attr = getattr(self.cursor, attr)
if attr in CursorWrapper.WRAP_ERROR_ATTRS:
return self.db.wrap_database_errors(cursor_attr)
else:
return cursor_attr
def __iter__(self):
with self.db.wrap_database_errors:
yield from self.cursor
def __enter__(self):
return self
def __exit__(self, type, value, traceback):
# Close instead of passing through to avoid backend-specific behavior
# (#17671). Catch errors liberally because errors in cleanup code
# aren't useful.
try:
self.close()
except self.db.Database.Error:
pass
# The following methods cannot be implemented in __getattr__, because the
# code must run when the method is invoked, not just when it is accessed.
def callproc(self, procname, params=None, kparams=None):
# Keyword parameters for callproc aren't supported in PEP 249, but the
# database driver may support them (e.g. cx_Oracle).
if kparams is not None and not self.db.features.supports_callproc_kwargs:
raise NotSupportedError(
'Keyword parameters for callproc are not supported on this '
'database backend.'
)
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
if params is None and kparams is None:
return self.cursor.callproc(procname)
elif kparams is None:
return self.cursor.callproc(procname, params)
else:
params = params or ()
return self.cursor.callproc(procname, params, kparams)
def execute(self, sql, params=None):
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
def executemany(self, sql, param_list):
return self._execute_with_wrappers(sql, param_list, many=True, executor=self._executemany)
def _execute_with_wrappers(self, sql, params, many, executor):
context = {'connection': self.db, 'cursor': self}
for wrapper in reversed(self.db.execute_wrappers):
executor = functools.partial(wrapper, executor)
return executor(sql, params, many, context)
def _execute(self, sql, params, *ignored_wrapper_args):
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
if params is None:
return self.cursor.execute(sql)
else:
return self.cursor.execute(sql, params)
def _executemany(self, sql, param_list, *ignored_wrapper_args):
self.db.validate_no_broken_transaction()
with self.db.wrap_database_errors:
return self.cursor.executemany(sql, param_list)
class CursorDebugWrapper(CursorWrapper):
# XXX callproc isn't instrumented at this time.
def execute(self, sql, params=None):
start = time()
try:
return super().execute(sql, params)
finally:
stop = time()
duration = stop - start
sql = self.db.ops.last_executed_query(self.cursor, sql, params)
self.db.queries_log.append({
'sql': sql,
'time': "%.3f" % duration,
})
logger.debug(
'(%.3f) %s; args=%s', duration, sql, params,
extra={'duration': duration, 'sql': sql, 'params': params}
)
def executemany(self, sql, param_list):
start = time()
try:
return super().executemany(sql, param_list)
finally:
stop = time()
duration = stop - start
try:
times = len(param_list)
except TypeError: # param_list could be an iterator
times = '?'
self.db.queries_log.append({
'sql': '%s times: %s' % (times, sql),
'time': "%.3f" % duration,
})
logger.debug(
'(%.3f) %s; args=%s', duration, sql, param_list,
extra={'duration': duration, 'sql': sql, 'params': param_list}
)
###############################################
# Converters from database (string) to Python #
###############################################
def typecast_date(s):
return datetime.date(*map(int, s.split('-'))) if s else None # return None if s is null
def typecast_time(s): # does NOT store time zone information
if not s:
return None
hour, minutes, seconds = s.split(':')
if '.' in seconds: # check whether seconds have a fractional part
seconds, microseconds = seconds.split('.')
else:
microseconds = '0'
return datetime.time(int(hour), int(minutes), int(seconds), int((microseconds + '000000')[:6]))
def typecast_timestamp(s): # does NOT store time zone information
# "2005-07-29 15:48:00.590358-05"
# "2005-07-29 09:56:00-05"
if not s:
return None
if ' ' not in s:
return typecast_date(s)
d, t = s.split()
# Extract timezone information, if it exists. Currently it's ignored.
if '-' in t:
t, tz = t.split('-', 1)
tz = '-' + tz
elif '+' in t:
t, tz = t.split('+', 1)
tz = '+' + tz
else:
tz = ''
dates = d.split('-')
times = t.split(':')
seconds = times[2]
if '.' in seconds: # check whether seconds have a fractional part
seconds, microseconds = seconds.split('.')
else:
microseconds = '0'
tzinfo = utc if settings.USE_TZ else None
return datetime.datetime(
int(dates[0]), int(dates[1]), int(dates[2]),
int(times[0]), int(times[1]), int(seconds),
int((microseconds + '000000')[:6]), tzinfo
)
###############################################
# Converters from Python to database (string) #
###############################################
def rev_typecast_decimal(d):
if d is None:
return None
return str(d)
def split_identifier(identifier):
"""
Split a SQL identifier into a two element tuple of (namespace, name).
The identifier could be a table, column, or sequence name might be prefixed
by a namespace.
"""
try:
namespace, name = identifier.split('"."')
except ValueError:
namespace, name = '', identifier
return namespace.strip('"'), name.strip('"')
def truncate_name(identifier, length=None, hash_len=4):
"""
Shorten a SQL identifier to a repeatable mangled version with the given
length.
If a quote stripped name contains a namespace, e.g. USERNAME"."TABLE,
truncate the table portion only.
"""
namespace, name = split_identifier(identifier)
if length is None or len(name) <= length:
return identifier
digest = hashlib.md5(force_bytes(name)).hexdigest()[:hash_len]
return '%s%s%s' % ('%s"."' % namespace if namespace else '', name[:length - hash_len], digest)
def format_number(value, max_digits, decimal_places):
"""
Format a number into a string with the requisite number of digits and
decimal places.
"""
if value is None:
return None
if isinstance(value, decimal.Decimal):
context = decimal.getcontext().copy()
if max_digits is not None:
context.prec = max_digits
if decimal_places is not None:
value = value.quantize(decimal.Decimal(1).scaleb(-decimal_places), context=context)
else:
context.traps[decimal.Rounded] = 1
value = context.create_decimal(value)
return "{:f}".format(value)
if decimal_places is not None:
return "%.*f" % (decimal_places, value)
return "{:f}".format(value)
def strip_quotes(table_name):
"""
Strip quotes off of quoted table names to make them safe for use in index
names, sequence names, etc. For example '"USER"."TABLE"' (an Oracle naming
scheme) becomes 'USER"."TABLE'.
"""
has_quotes = table_name.startswith('"') and table_name.endswith('"')
return table_name[1:-1] if has_quotes else table_name
|
ac0141e5b51d9e4e63724213e0fc15c04b84e9a8f875bb5ab111dc4672321fa6 | from django.dispatch import Signal
connection_created = Signal(providing_args=["connection"])
|
02c264e19d46ebe84b2515a4c8e2e93f7940a719f83a63f8875caa3eb9d495f5 | from .fields import AddField, AlterField, RemoveField, RenameField
from .models import (
AddIndex, AlterIndexTogether, AlterModelManagers, AlterModelOptions,
AlterModelTable, AlterOrderWithRespectTo, AlterUniqueTogether, CreateModel,
DeleteModel, RemoveIndex, RenameModel,
)
from .special import RunPython, RunSQL, SeparateDatabaseAndState
__all__ = [
'CreateModel', 'DeleteModel', 'AlterModelTable', 'AlterUniqueTogether',
'RenameModel', 'AlterIndexTogether', 'AlterModelOptions', 'AddIndex',
'RemoveIndex', 'AddField', 'RemoveField', 'AlterField', 'RenameField',
'SeparateDatabaseAndState', 'RunSQL', 'RunPython',
'AlterOrderWithRespectTo', 'AlterModelManagers',
]
|
394b4bd2d63b46eb4db541ce9aa4a8259128448de320a49106e5cf9360a9ee2e | from django.db import models
from django.db.migrations.operations.base import Operation
from django.db.migrations.state import ModelState
from django.db.models.options import normalize_together
from django.utils.functional import cached_property
from .fields import (
AddField, AlterField, FieldOperation, RemoveField, RenameField,
)
def _check_for_duplicates(arg_name, objs):
used_vals = set()
for val in objs:
if val in used_vals:
raise ValueError(
"Found duplicate value %s in CreateModel %s argument." % (val, arg_name)
)
used_vals.add(val)
class ModelOperation(Operation):
def __init__(self, name):
self.name = name
@cached_property
def name_lower(self):
return self.name.lower()
def references_model(self, name, app_label=None):
return name.lower() == self.name_lower
def reduce(self, operation, in_between, app_label=None):
return (
super().reduce(operation, in_between, app_label=app_label) or
not operation.references_model(self.name, app_label)
)
class CreateModel(ModelOperation):
"""Create a model's table."""
serialization_expand_args = ['fields', 'options', 'managers']
def __init__(self, name, fields, options=None, bases=None, managers=None):
self.fields = fields
self.options = options or {}
self.bases = bases or (models.Model,)
self.managers = managers or []
super().__init__(name)
# Sanity-check that there are no duplicated field names, bases, or
# manager names
_check_for_duplicates('fields', (name for name, _ in self.fields))
_check_for_duplicates('bases', (
base._meta.label_lower if hasattr(base, '_meta') else
base.lower() if isinstance(base, str) else base
for base in self.bases
))
_check_for_duplicates('managers', (name for name, _ in self.managers))
def deconstruct(self):
kwargs = {
'name': self.name,
'fields': self.fields,
}
if self.options:
kwargs['options'] = self.options
if self.bases and self.bases != (models.Model,):
kwargs['bases'] = self.bases
if self.managers and self.managers != [('objects', models.Manager())]:
kwargs['managers'] = self.managers
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.add_model(ModelState(
app_label,
self.name,
list(self.fields),
dict(self.options),
tuple(self.bases),
list(self.managers),
))
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def describe(self):
return "Create %smodel %s" % ("proxy " if self.options.get("proxy", False) else "", self.name)
def references_model(self, name, app_label=None):
name_lower = name.lower()
if name_lower == self.name_lower:
return True
# Check we didn't inherit from the model
models_to_check = [
base for base in self.bases
if base is not models.Model and isinstance(base, (models.base.ModelBase, str))
]
# Check we have no FKs/M2Ms with it
for fname, field in self.fields:
if field.remote_field:
models_to_check.append(field.remote_field.model)
# Now go over all the models and check against them
for model in models_to_check:
model_app_label, model_name = self.model_to_key(model)
if model_name.lower() == name_lower:
if app_label is None or not model_app_label or model_app_label == app_label:
return True
return False
def model_to_key(self, model):
"""
Take either a model class or an "app_label.ModelName" string
and return (app_label, object_name).
"""
if isinstance(model, str):
return model.split(".", 1)
else:
return model._meta.app_label, model._meta.object_name
def reduce(self, operation, in_between, app_label=None):
if (isinstance(operation, DeleteModel) and
self.name_lower == operation.name_lower and
not self.options.get("proxy", False)):
return []
elif isinstance(operation, RenameModel) and self.name_lower == operation.old_name_lower:
return [
CreateModel(
operation.new_name,
fields=self.fields,
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterModelOptions) and self.name_lower == operation.name_lower:
return [
CreateModel(
self.name,
fields=self.fields,
options={**self.options, **operation.options},
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, FieldOperation) and self.name_lower == operation.model_name_lower:
if isinstance(operation, AddField):
# Don't allow optimizations of FKs through models they reference
if hasattr(operation.field, "remote_field") and operation.field.remote_field:
for between in in_between:
# Check that it doesn't point to the model
app_label, object_name = self.model_to_key(operation.field.remote_field.model)
if between.references_model(object_name, app_label):
return False
# Check that it's not through the model
if getattr(operation.field.remote_field, "through", None):
app_label, object_name = self.model_to_key(operation.field.remote_field.through)
if between.references_model(object_name, app_label):
return False
return [
CreateModel(
self.name,
fields=self.fields + [(operation.name, operation.field)],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, AlterField):
return [
CreateModel(
self.name,
fields=[
(n, operation.field if n == operation.name else v)
for n, v in self.fields
],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RemoveField):
return [
CreateModel(
self.name,
fields=[
(n, v)
for n, v in self.fields
if n.lower() != operation.name_lower
],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
elif isinstance(operation, RenameField):
return [
CreateModel(
self.name,
fields=[
(operation.new_name if n == operation.old_name else n, v)
for n, v in self.fields
],
options=self.options,
bases=self.bases,
managers=self.managers,
),
]
return super().reduce(operation, in_between, app_label=app_label)
class DeleteModel(ModelOperation):
"""Drop a model's table."""
def deconstruct(self):
kwargs = {
'name': self.name,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.remove_model(app_label, self.name_lower)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.delete_model(model)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.create_model(model)
def describe(self):
return "Delete model %s" % self.name
class RenameModel(ModelOperation):
"""Rename a model."""
def __init__(self, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
super().__init__(old_name)
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
'old_name': self.old_name,
'new_name': self.new_name,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
# Add a new model.
renamed_model = state.models[app_label, self.old_name_lower].clone()
renamed_model.name = self.new_name
state.models[app_label, self.new_name_lower] = renamed_model
# Repoint all fields pointing to the old model to the new one.
old_model_tuple = app_label, self.old_name_lower
new_remote_model = '%s.%s' % (app_label, self.new_name)
to_reload = []
for (model_app_label, model_name), model_state in state.models.items():
model_changed = False
for index, (name, field) in enumerate(model_state.fields):
changed_field = None
remote_field = field.remote_field
if remote_field:
remote_model_tuple = self._get_model_tuple(
remote_field.model, model_app_label, model_name
)
if remote_model_tuple == old_model_tuple:
changed_field = field.clone()
changed_field.remote_field.model = new_remote_model
through_model = getattr(remote_field, 'through', None)
if through_model:
through_model_tuple = self._get_model_tuple(
through_model, model_app_label, model_name
)
if through_model_tuple == old_model_tuple:
if changed_field is None:
changed_field = field.clone()
changed_field.remote_field.through = new_remote_model
if changed_field:
model_state.fields[index] = name, changed_field
model_changed = True
if model_changed:
to_reload.append((model_app_label, model_name))
# Reload models related to old model before removing the old model.
state.reload_models(to_reload, delay=True)
# Remove the old model.
state.remove_model(app_label, self.old_name_lower)
state.reload_model(app_label, self.new_name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.new_name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.old_name)
# Move the main table
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
# Alter the fields pointing to us
for related_object in old_model._meta.related_objects:
if related_object.related_model == old_model:
model = new_model
related_key = (app_label, self.new_name_lower)
else:
model = related_object.related_model
related_key = (
related_object.related_model._meta.app_label,
related_object.related_model._meta.model_name,
)
to_field = to_state.apps.get_model(
*related_key
)._meta.get_field(related_object.field.name)
schema_editor.alter_field(
model,
related_object.field,
to_field,
)
# Rename M2M fields whose name is based on this model's name.
fields = zip(old_model._meta.local_many_to_many, new_model._meta.local_many_to_many)
for (old_field, new_field) in fields:
# Skip self-referential fields as these are renamed above.
if new_field.model == new_field.related_model or not new_field.remote_field.through._meta.auto_created:
continue
# Rename the M2M table that's based on this model's name.
old_m2m_model = old_field.remote_field.through
new_m2m_model = new_field.remote_field.through
schema_editor.alter_db_table(
new_m2m_model,
old_m2m_model._meta.db_table,
new_m2m_model._meta.db_table,
)
# Rename the column in the M2M table that's based on this
# model's name.
schema_editor.alter_field(
new_m2m_model,
old_m2m_model._meta.get_field(old_model._meta.model_name),
new_m2m_model._meta.get_field(new_model._meta.model_name),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.new_name_lower, self.old_name_lower = self.old_name_lower, self.new_name_lower
self.new_name, self.old_name = self.old_name, self.new_name
self.database_forwards(app_label, schema_editor, from_state, to_state)
self.new_name_lower, self.old_name_lower = self.old_name_lower, self.new_name_lower
self.new_name, self.old_name = self.old_name, self.new_name
def references_model(self, name, app_label=None):
return (
name.lower() == self.old_name_lower or
name.lower() == self.new_name_lower
)
def describe(self):
return "Rename model %s to %s" % (self.old_name, self.new_name)
def reduce(self, operation, in_between, app_label=None):
if (isinstance(operation, RenameModel) and
self.new_name_lower == operation.old_name_lower):
return [
RenameModel(
self.old_name,
operation.new_name,
),
]
# Skip `ModelOperation.reduce` as we want to run `references_model`
# against self.new_name.
return (
super(ModelOperation, self).reduce(operation, in_between, app_label=app_label) or
not operation.references_model(self.new_name, app_label)
)
class AlterModelTable(ModelOperation):
"""Rename a model's table."""
def __init__(self, name, table):
self.table = table
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'table': self.table,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
state.models[app_label, self.name_lower].options["db_table"] = self.table
state.reload_model(app_label, self.name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
schema_editor.alter_db_table(
new_model,
old_model._meta.db_table,
new_model._meta.db_table,
)
# Rename M2M fields whose name is based on this model's db_table
for (old_field, new_field) in zip(old_model._meta.local_many_to_many, new_model._meta.local_many_to_many):
if new_field.remote_field.through._meta.auto_created:
schema_editor.alter_db_table(
new_field.remote_field.through,
old_field.remote_field.through._meta.db_table,
new_field.remote_field.through._meta.db_table,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Rename table for %s to %s" % (
self.name,
self.table if self.table is not None else "(default)"
)
def reduce(self, operation, in_between, app_label=None):
if isinstance(operation, (AlterModelTable, DeleteModel)) and self.name_lower == operation.name_lower:
return [operation]
return super().reduce(operation, in_between, app_label=app_label)
class ModelOptionOperation(ModelOperation):
def reduce(self, operation, in_between, app_label=None):
if isinstance(operation, (self.__class__, DeleteModel)) and self.name_lower == operation.name_lower:
return [operation]
return super().reduce(operation, in_between, app_label=app_label)
class FieldRelatedOptionOperation(ModelOptionOperation):
def reduce(self, operation, in_between, app_label=None):
if (isinstance(operation, FieldOperation) and
self.name_lower == operation.model_name_lower and
not self.references_field(operation.model_name, operation.name)):
return [operation, self]
return super().reduce(operation, in_between, app_label=app_label)
class AlterUniqueTogether(FieldRelatedOptionOperation):
"""
Change the value of unique_together to the target one.
Input value of unique_together must be a set of tuples.
"""
option_name = "unique_together"
def __init__(self, name, unique_together):
unique_together = normalize_together(unique_together)
self.unique_together = {tuple(cons) for cons in unique_together}
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'unique_together': self.unique_together,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name_lower]
model_state.options[self.option_name] = self.unique_together
state.reload_model(app_label, self.name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
schema_editor.alter_unique_together(
new_model,
getattr(old_model._meta, self.option_name, set()),
getattr(new_model._meta, self.option_name, set()),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label=None):
return (
self.references_model(model_name, app_label) and
(
not self.unique_together or
any((name in together) for together in self.unique_together)
)
)
def describe(self):
return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.unique_together or ''))
class AlterIndexTogether(FieldRelatedOptionOperation):
"""
Change the value of index_together to the target one.
Input value of index_together must be a set of tuples.
"""
option_name = "index_together"
def __init__(self, name, index_together):
index_together = normalize_together(index_together)
self.index_together = {tuple(cons) for cons in index_together}
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'index_together': self.index_together,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name_lower]
model_state.options[self.option_name] = self.index_together
state.reload_model(app_label, self.name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
new_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, new_model):
old_model = from_state.apps.get_model(app_label, self.name)
schema_editor.alter_index_together(
new_model,
getattr(old_model._meta, self.option_name, set()),
getattr(new_model._meta, self.option_name, set()),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
return self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label=None):
return (
self.references_model(model_name, app_label) and
(
not self.index_together or
any((name in together) for together in self.index_together)
)
)
def describe(self):
return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.index_together or ''))
class AlterOrderWithRespectTo(FieldRelatedOptionOperation):
"""Represent a change with the order_with_respect_to option."""
def __init__(self, name, order_with_respect_to):
self.order_with_respect_to = order_with_respect_to
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'order_with_respect_to': self.order_with_respect_to,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name_lower]
model_state.options['order_with_respect_to'] = self.order_with_respect_to
state.reload_model(app_label, self.name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.name)
# Remove a field if we need to
if from_model._meta.order_with_respect_to and not to_model._meta.order_with_respect_to:
schema_editor.remove_field(from_model, from_model._meta.get_field("_order"))
# Add a field if we need to (altering the column is untouched as
# it's likely a rename)
elif to_model._meta.order_with_respect_to and not from_model._meta.order_with_respect_to:
field = to_model._meta.get_field("_order")
if not field.has_default():
field.default = 0
schema_editor.add_field(
from_model,
field,
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.database_forwards(app_label, schema_editor, from_state, to_state)
def references_field(self, model_name, name, app_label=None):
return (
self.references_model(model_name, app_label) and
(
self.order_with_respect_to is None or
name == self.order_with_respect_to
)
)
def describe(self):
return "Set order_with_respect_to on %s to %s" % (self.name, self.order_with_respect_to)
class AlterModelOptions(ModelOptionOperation):
"""
Set new model options that don't directly affect the database schema
(like verbose_name, permissions, ordering). Python code in migrations
may still need them.
"""
# Model options we want to compare and preserve in an AlterModelOptions op
ALTER_OPTION_KEYS = [
"base_manager_name",
"default_manager_name",
"get_latest_by",
"managed",
"ordering",
"permissions",
"default_permissions",
"select_on_save",
"verbose_name",
"verbose_name_plural",
]
def __init__(self, name, options):
self.options = options
super().__init__(name)
def deconstruct(self):
kwargs = {
'name': self.name,
'options': self.options,
}
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name_lower]
model_state.options = {**model_state.options, **self.options}
for key in self.ALTER_OPTION_KEYS:
if key not in self.options:
model_state.options.pop(key, False)
state.reload_model(app_label, self.name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
pass
def database_backwards(self, app_label, schema_editor, from_state, to_state):
pass
def describe(self):
return "Change Meta options on %s" % self.name
class AlterModelManagers(ModelOptionOperation):
"""Alter the model's managers."""
serialization_expand_args = ['managers']
def __init__(self, name, managers):
self.managers = managers
super().__init__(name)
def deconstruct(self):
return (
self.__class__.__qualname__,
[self.name, self.managers],
{}
)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.name_lower]
model_state.managers = list(self.managers)
state.reload_model(app_label, self.name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
pass
def database_backwards(self, app_label, schema_editor, from_state, to_state):
pass
def describe(self):
return "Change managers on %s" % self.name
class IndexOperation(Operation):
option_name = 'indexes'
@cached_property
def model_name_lower(self):
return self.model_name.lower()
class AddIndex(IndexOperation):
"""Add an index on a model."""
def __init__(self, model_name, index):
self.model_name = model_name
if not index.name:
raise ValueError(
"Indexes passed to AddIndex operations require a name "
"argument. %r doesn't have one." % index
)
self.index = index
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.model_name_lower]
indexes = list(model_state.options[self.option_name])
indexes.append(self.index.clone())
model_state.options[self.option_name] = indexes
state.reload_model(app_label, self.model_name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.add_index(model, self.index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
schema_editor.remove_index(model, self.index)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'index': self.index,
}
return (
self.__class__.__qualname__,
[],
kwargs,
)
def describe(self):
return 'Create index %s on field(s) %s of model %s' % (
self.index.name,
', '.join(self.index.fields),
self.model_name,
)
class RemoveIndex(IndexOperation):
"""Remove an index from a model."""
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.model_name_lower]
indexes = model_state.options[self.option_name]
model_state.options[self.option_name] = [idx for idx in indexes if idx.name != self.name]
state.reload_model(app_label, self.model_name_lower, delay=True)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
from_model_state = from_state.models[app_label, self.model_name_lower]
index = from_model_state.get_index_by_name(self.name)
schema_editor.remove_index(model, index)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, model):
to_model_state = to_state.models[app_label, self.model_name_lower]
index = to_model_state.get_index_by_name(self.name)
schema_editor.add_index(model, index)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
}
return (
self.__class__.__qualname__,
[],
kwargs,
)
def describe(self):
return 'Remove index %s from %s' % (self.name, self.model_name)
|
93ff239da56957209e6cec53c96216e507dd3024b54db77bb7d9adb330c26404 | from django.db import router
from django.db.models.fields.related import RECURSIVE_RELATIONSHIP_CONSTANT
class Operation:
"""
Base class for migration operations.
It's responsible for both mutating the in-memory model state
(see db/migrations/state.py) to represent what it performs, as well
as actually performing it against a live database.
Note that some operations won't modify memory state at all (e.g. data
copying operations), and some will need their modifications to be
optionally specified by the user (e.g. custom Python code snippets)
Due to the way this class deals with deconstruction, it should be
considered immutable.
"""
# If this migration can be run in reverse.
# Some operations are impossible to reverse, like deleting data.
reversible = True
# Can this migration be represented as SQL? (things like RunPython cannot)
reduces_to_sql = True
# Should this operation be forced as atomic even on backends with no
# DDL transaction support (i.e., does it have no DDL, like RunPython)
atomic = False
# Should this operation be considered safe to elide and optimize across?
elidable = False
serialization_expand_args = []
def __new__(cls, *args, **kwargs):
# We capture the arguments to make returning them trivial
self = object.__new__(cls)
self._constructor_args = (args, kwargs)
return self
def deconstruct(self):
"""
Return a 3-tuple of class import path (or just name if it lives
under django.db.migrations), positional arguments, and keyword
arguments.
"""
return (
self.__class__.__name__,
self._constructor_args[0],
self._constructor_args[1],
)
def state_forwards(self, app_label, state):
"""
Take the state from the previous migration, and mutate it
so that it matches what this migration would perform.
"""
raise NotImplementedError('subclasses of Operation must provide a state_forwards() method')
def database_forwards(self, app_label, schema_editor, from_state, to_state):
"""
Perform the mutation on the database schema in the normal
(forwards) direction.
"""
raise NotImplementedError('subclasses of Operation must provide a database_forwards() method')
def database_backwards(self, app_label, schema_editor, from_state, to_state):
"""
Perform the mutation on the database schema in the reverse
direction - e.g. if this were CreateModel, it would in fact
drop the model's table.
"""
raise NotImplementedError('subclasses of Operation must provide a database_backwards() method')
def describe(self):
"""
Output a brief summary of what the action does.
"""
return "%s: %s" % (self.__class__.__name__, self._constructor_args)
def references_model(self, name, app_label=None):
"""
Return True if there is a chance this operation references the given
model name (as a string), with an optional app label for accuracy.
Used for optimization. If in doubt, return True;
returning a false positive will merely make the optimizer a little
less efficient, while returning a false negative may result in an
unusable optimized migration.
"""
return True
def references_field(self, model_name, name, app_label=None):
"""
Return True if there is a chance this operation references the given
field name, with an optional app label for accuracy.
Used for optimization. If in doubt, return True.
"""
return self.references_model(model_name, app_label)
def allow_migrate_model(self, connection_alias, model):
"""
Return wether or not a model may be migrated.
This is a thin wrapper around router.allow_migrate_model() that
preemptively rejects any proxy, swapped out, or unmanaged model.
"""
if not model._meta.can_migrate(connection_alias):
return False
return router.allow_migrate_model(connection_alias, model)
def reduce(self, operation, in_between, app_label=None):
"""
Return either a list of operations the actual operation should be
replaced with or a boolean that indicates whether or not the specified
operation can be optimized across.
"""
if self.elidable:
return [operation]
elif operation.elidable:
return [self]
return False
def _get_model_tuple(self, remote_model, app_label, model_name):
if remote_model == RECURSIVE_RELATIONSHIP_CONSTANT:
return app_label, model_name.lower()
elif '.' in remote_model:
return tuple(remote_model.lower().split('.'))
else:
return app_label, remote_model.lower()
def __repr__(self):
return "<%s %s%s>" % (
self.__class__.__name__,
", ".join(map(repr, self._constructor_args[0])),
",".join(" %s=%r" % x for x in self._constructor_args[1].items()),
)
|
eaf3b645181a50f9f11236e44d7dd0c0037e2da69d6451d8a451e8b8068c9a28 | from django.db import router
from .base import Operation
class SeparateDatabaseAndState(Operation):
"""
Take two lists of operations - ones that will be used for the database,
and ones that will be used for the state change. This allows operations
that don't support state change to have it applied, or have operations
that affect the state or not the database, or so on.
"""
serialization_expand_args = ['database_operations', 'state_operations']
def __init__(self, database_operations=None, state_operations=None):
self.database_operations = database_operations or []
self.state_operations = state_operations or []
def deconstruct(self):
kwargs = {}
if self.database_operations:
kwargs['database_operations'] = self.database_operations
if self.state_operations:
kwargs['state_operations'] = self.state_operations
return (
self.__class__.__qualname__,
[],
kwargs
)
def state_forwards(self, app_label, state):
for state_operation in self.state_operations:
state_operation.state_forwards(app_label, state)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
# We calculate state separately in here since our state functions aren't useful
for database_operation in self.database_operations:
to_state = from_state.clone()
database_operation.state_forwards(app_label, to_state)
database_operation.database_forwards(app_label, schema_editor, from_state, to_state)
from_state = to_state
def database_backwards(self, app_label, schema_editor, from_state, to_state):
# We calculate state separately in here since our state functions aren't useful
to_states = {}
for dbop in self.database_operations:
to_states[dbop] = to_state
to_state = to_state.clone()
dbop.state_forwards(app_label, to_state)
# to_state now has the states of all the database_operations applied
# which is the from_state for the backwards migration of the last
# operation.
for database_operation in reversed(self.database_operations):
from_state = to_state
to_state = to_states[database_operation]
database_operation.database_backwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Custom state/database change combination"
class RunSQL(Operation):
"""
Run some raw SQL. A reverse SQL statement may be provided.
Also accept a list of operations that represent the state change effected
by this SQL change, in case it's custom column/table creation/deletion.
"""
noop = ''
def __init__(self, sql, reverse_sql=None, state_operations=None, hints=None, elidable=False):
self.sql = sql
self.reverse_sql = reverse_sql
self.state_operations = state_operations or []
self.hints = hints or {}
self.elidable = elidable
def deconstruct(self):
kwargs = {
'sql': self.sql,
}
if self.reverse_sql is not None:
kwargs['reverse_sql'] = self.reverse_sql
if self.state_operations:
kwargs['state_operations'] = self.state_operations
if self.hints:
kwargs['hints'] = self.hints
return (
self.__class__.__qualname__,
[],
kwargs
)
@property
def reversible(self):
return self.reverse_sql is not None
def state_forwards(self, app_label, state):
for state_operation in self.state_operations:
state_operation.state_forwards(app_label, state)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
if router.allow_migrate(schema_editor.connection.alias, app_label, **self.hints):
self._run_sql(schema_editor, self.sql)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if self.reverse_sql is None:
raise NotImplementedError("You cannot reverse this operation")
if router.allow_migrate(schema_editor.connection.alias, app_label, **self.hints):
self._run_sql(schema_editor, self.reverse_sql)
def describe(self):
return "Raw SQL operation"
def _run_sql(self, schema_editor, sqls):
if isinstance(sqls, (list, tuple)):
for sql in sqls:
params = None
if isinstance(sql, (list, tuple)):
elements = len(sql)
if elements == 2:
sql, params = sql
else:
raise ValueError("Expected a 2-tuple but got %d" % elements)
schema_editor.execute(sql, params=params)
elif sqls != RunSQL.noop:
statements = schema_editor.connection.ops.prepare_sql_script(sqls)
for statement in statements:
schema_editor.execute(statement, params=None)
class RunPython(Operation):
"""
Run Python code in a context suitable for doing versioned ORM operations.
"""
reduces_to_sql = False
def __init__(self, code, reverse_code=None, atomic=None, hints=None, elidable=False):
self.atomic = atomic
# Forwards code
if not callable(code):
raise ValueError("RunPython must be supplied with a callable")
self.code = code
# Reverse code
if reverse_code is None:
self.reverse_code = None
else:
if not callable(reverse_code):
raise ValueError("RunPython must be supplied with callable arguments")
self.reverse_code = reverse_code
self.hints = hints or {}
self.elidable = elidable
def deconstruct(self):
kwargs = {
'code': self.code,
}
if self.reverse_code is not None:
kwargs['reverse_code'] = self.reverse_code
if self.atomic is not None:
kwargs['atomic'] = self.atomic
if self.hints:
kwargs['hints'] = self.hints
return (
self.__class__.__qualname__,
[],
kwargs
)
@property
def reversible(self):
return self.reverse_code is not None
def state_forwards(self, app_label, state):
# RunPython objects have no state effect. To add some, combine this
# with SeparateDatabaseAndState.
pass
def database_forwards(self, app_label, schema_editor, from_state, to_state):
# RunPython has access to all models. Ensure that all models are
# reloaded in case any are delayed.
from_state.clear_delayed_apps_cache()
if router.allow_migrate(schema_editor.connection.alias, app_label, **self.hints):
# We now execute the Python code in a context that contains a 'models'
# object, representing the versioned models as an app registry.
# We could try to override the global cache, but then people will still
# use direct imports, so we go with a documentation approach instead.
self.code(from_state.apps, schema_editor)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
if self.reverse_code is None:
raise NotImplementedError("You cannot reverse this operation")
if router.allow_migrate(schema_editor.connection.alias, app_label, **self.hints):
self.reverse_code(from_state.apps, schema_editor)
def describe(self):
return "Raw Python operation"
@staticmethod
def noop(apps, schema_editor):
return None
|
3a55122631c7186cd0c393f79bd2846474c6399a5231b9143829a07f7a301288 | from django.core.exceptions import FieldDoesNotExist
from django.db.models.fields import NOT_PROVIDED
from django.utils.functional import cached_property
from .base import Operation
from .utils import is_referenced_by_foreign_key
class FieldOperation(Operation):
def __init__(self, model_name, name):
self.model_name = model_name
self.name = name
@cached_property
def model_name_lower(self):
return self.model_name.lower()
@cached_property
def name_lower(self):
return self.name.lower()
def is_same_model_operation(self, operation):
return self.model_name_lower == operation.model_name_lower
def is_same_field_operation(self, operation):
return self.is_same_model_operation(operation) and self.name_lower == operation.name_lower
def references_model(self, name, app_label=None):
return name.lower() == self.model_name_lower
def references_field(self, model_name, name, app_label=None):
return self.references_model(model_name) and name.lower() == self.name_lower
def reduce(self, operation, in_between, app_label=None):
return (
super().reduce(operation, in_between, app_label=app_label) or
not operation.references_field(self.model_name, self.name, app_label)
)
class AddField(FieldOperation):
"""Add a field to a model."""
def __init__(self, model_name, name, field, preserve_default=True):
self.field = field
self.preserve_default = preserve_default
super().__init__(model_name, name)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
'field': self.field,
}
if self.preserve_default is not True:
kwargs['preserve_default'] = self.preserve_default
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
# If preserve default is off, don't use the default for future state
if not self.preserve_default:
field = self.field.clone()
field.default = NOT_PROVIDED
else:
field = self.field
state.models[app_label, self.model_name_lower].fields.append((self.name, field))
# Delay rendering of relationships if it's not a relational field
delay = not field.is_relation
state.reload_model(app_label, self.model_name_lower, delay=delay)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
field = to_model._meta.get_field(self.name)
if not self.preserve_default:
field.default = self.field.default
schema_editor.add_field(
from_model,
field,
)
if not self.preserve_default:
field.default = NOT_PROVIDED
def database_backwards(self, app_label, schema_editor, from_state, to_state):
from_model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, from_model):
schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
def describe(self):
return "Add field %s to %s" % (self.name, self.model_name)
def reduce(self, operation, in_between, app_label=None):
if isinstance(operation, FieldOperation) and self.is_same_field_operation(operation):
if isinstance(operation, AlterField):
return [
AddField(
model_name=self.model_name,
name=operation.name,
field=operation.field,
),
]
elif isinstance(operation, RemoveField):
return []
elif isinstance(operation, RenameField):
return [
AddField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, in_between, app_label=app_label)
class RemoveField(FieldOperation):
"""Remove a field from a model."""
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
}
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
new_fields = []
old_field = None
for name, instance in state.models[app_label, self.model_name_lower].fields:
if name != self.name:
new_fields.append((name, instance))
else:
old_field = instance
state.models[app_label, self.model_name_lower].fields = new_fields
# Delay rendering of relationships if it's not a relational field
delay = not old_field.is_relation
state.reload_model(app_label, self.model_name_lower, delay=delay)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
from_model = from_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, from_model):
schema_editor.remove_field(from_model, from_model._meta.get_field(self.name))
def database_backwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.add_field(from_model, to_model._meta.get_field(self.name))
def describe(self):
return "Remove field %s from %s" % (self.name, self.model_name)
class AlterField(FieldOperation):
"""
Alter a field's database column (e.g. null, max_length) to the provided
new field.
"""
def __init__(self, model_name, name, field, preserve_default=True):
self.field = field
self.preserve_default = preserve_default
super().__init__(model_name, name)
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'name': self.name,
'field': self.field,
}
if self.preserve_default is not True:
kwargs['preserve_default'] = self.preserve_default
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
if not self.preserve_default:
field = self.field.clone()
field.default = NOT_PROVIDED
else:
field = self.field
state.models[app_label, self.model_name_lower].fields = [
(n, field if n == self.name else f)
for n, f in
state.models[app_label, self.model_name_lower].fields
]
# TODO: investigate if old relational fields must be reloaded or if it's
# sufficient if the new field is (#27737).
# Delay rendering of relationships if it's not a relational field and
# not referenced by a foreign key.
delay = (
not field.is_relation and
not is_referenced_by_foreign_key(state, self.model_name_lower, self.field, self.name)
)
state.reload_model(app_label, self.model_name_lower, delay=delay)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
from_field = from_model._meta.get_field(self.name)
to_field = to_model._meta.get_field(self.name)
if not self.preserve_default:
to_field.default = self.field.default
schema_editor.alter_field(from_model, from_field, to_field)
if not self.preserve_default:
to_field.default = NOT_PROVIDED
def database_backwards(self, app_label, schema_editor, from_state, to_state):
self.database_forwards(app_label, schema_editor, from_state, to_state)
def describe(self):
return "Alter field %s on %s" % (self.name, self.model_name)
def reduce(self, operation, in_between, app_label=None):
if isinstance(operation, RemoveField) and self.is_same_field_operation(operation):
return [operation]
elif isinstance(operation, RenameField) and self.is_same_field_operation(operation):
return [
operation,
AlterField(
model_name=self.model_name,
name=operation.new_name,
field=self.field,
),
]
return super().reduce(operation, in_between, app_label=app_label)
class RenameField(FieldOperation):
"""Rename a field on the model. Might affect db_column too."""
def __init__(self, model_name, old_name, new_name):
self.old_name = old_name
self.new_name = new_name
super().__init__(model_name, old_name)
@cached_property
def old_name_lower(self):
return self.old_name.lower()
@cached_property
def new_name_lower(self):
return self.new_name.lower()
def deconstruct(self):
kwargs = {
'model_name': self.model_name,
'old_name': self.old_name,
'new_name': self.new_name,
}
return (
self.__class__.__name__,
[],
kwargs
)
def state_forwards(self, app_label, state):
model_state = state.models[app_label, self.model_name_lower]
# Rename the field
fields = model_state.fields
found = False
delay = True
for index, (name, field) in enumerate(fields):
if not found and name == self.old_name:
fields[index] = (self.new_name, field)
found = True
# Fix from_fields to refer to the new field.
from_fields = getattr(field, 'from_fields', None)
if from_fields:
field.from_fields = tuple([
self.new_name if from_field_name == self.old_name else from_field_name
for from_field_name in from_fields
])
# Delay rendering of relationships if it's not a relational
# field and not referenced by a foreign key.
delay = delay and (
not field.is_relation and
not is_referenced_by_foreign_key(state, self.model_name_lower, field, self.name)
)
if not found:
raise FieldDoesNotExist(
"%s.%s has no field named '%s'" % (app_label, self.model_name, self.old_name)
)
# Fix index/unique_together to refer to the new field
options = model_state.options
for option in ('index_together', 'unique_together'):
if option in options:
options[option] = [
[self.new_name if n == self.old_name else n for n in together]
for together in options[option]
]
# Fix to_fields to refer to the new field.
model_tuple = app_label, self.model_name_lower
for (model_app_label, model_name), model_state in state.models.items():
for index, (name, field) in enumerate(model_state.fields):
remote_field = field.remote_field
if remote_field:
remote_model_tuple = self._get_model_tuple(
remote_field.model, model_app_label, model_name
)
if remote_model_tuple == model_tuple:
if getattr(remote_field, 'field_name', None) == self.old_name:
remote_field.field_name = self.new_name
to_fields = getattr(field, 'to_fields', None)
if to_fields:
field.to_fields = tuple([
self.new_name if to_field_name == self.old_name else to_field_name
for to_field_name in to_fields
])
state.reload_model(app_label, self.model_name_lower, delay=delay)
def database_forwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.alter_field(
from_model,
from_model._meta.get_field(self.old_name),
to_model._meta.get_field(self.new_name),
)
def database_backwards(self, app_label, schema_editor, from_state, to_state):
to_model = to_state.apps.get_model(app_label, self.model_name)
if self.allow_migrate_model(schema_editor.connection.alias, to_model):
from_model = from_state.apps.get_model(app_label, self.model_name)
schema_editor.alter_field(
from_model,
from_model._meta.get_field(self.new_name),
to_model._meta.get_field(self.old_name),
)
def describe(self):
return "Rename field %s on %s to %s" % (self.old_name, self.model_name, self.new_name)
def references_field(self, model_name, name, app_label=None):
return self.references_model(model_name) and (
name.lower() == self.old_name_lower or
name.lower() == self.new_name_lower
)
def reduce(self, operation, in_between, app_label=None):
if (isinstance(operation, RenameField) and
self.is_same_model_operation(operation) and
self.new_name_lower == operation.old_name_lower):
return [
RenameField(
self.model_name,
self.old_name,
operation.new_name,
),
]
# Skip `FieldOperation.reduce` as we want to run `references_field`
# against self.new_name.
return (
super(FieldOperation, self).reduce(operation, in_between, app_label=app_label) or
not operation.references_field(self.model_name, self.new_name, app_label)
)
|
135a40c70a2eb7335ed130d9053686c23b6eee9d959add78b0589d2e5feadce2 | def is_referenced_by_foreign_key(state, model_name_lower, field, field_name):
for state_app_label, state_model in state.models:
for _, f in state.models[state_app_label, state_model].fields:
if (f.related_model and
'%s.%s' % (state_app_label, model_name_lower) == f.related_model.lower() and
hasattr(f, 'to_fields')):
if (f.to_fields[0] is None and field.primary_key) or field_name in f.to_fields:
return True
return False
|
f93f6b21ae1a3a0cb7532f10d109138fc369bb1d04f0fe1949501ff63b0c7fa2 | from django.db.models.lookups import (
Exact, GreaterThan, GreaterThanOrEqual, In, IsNull, LessThan,
LessThanOrEqual,
)
class MultiColSource:
contains_aggregate = False
def __init__(self, alias, targets, sources, field):
self.targets, self.sources, self.field, self.alias = targets, sources, field, alias
self.output_field = self.field
def __repr__(self):
return "{}({}, {})".format(
self.__class__.__name__, self.alias, self.field)
def relabeled_clone(self, relabels):
return self.__class__(relabels.get(self.alias, self.alias),
self.targets, self.sources, self.field)
def get_lookup(self, lookup):
return self.output_field.get_lookup(lookup)
def get_normalized_value(value, lhs):
from django.db.models import Model
if isinstance(value, Model):
value_list = []
sources = lhs.output_field.get_path_info()[-1].target_fields
for source in sources:
while not isinstance(value, source.model) and source.remote_field:
source = source.remote_field.model._meta.get_field(source.remote_field.field_name)
try:
value_list.append(getattr(value, source.attname))
except AttributeError:
# A case like Restaurant.objects.filter(place=restaurant_instance),
# where place is a OneToOneField and the primary key of Restaurant.
return (value.pk,)
return tuple(value_list)
if not isinstance(value, tuple):
return (value,)
return value
class RelatedIn(In):
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource) and self.rhs_is_direct_value():
# If we get here, we are dealing with single-column relations.
self.rhs = [get_normalized_value(val, self.lhs)[0] for val in self.rhs]
# We need to run the related field's get_prep_value(). Consider case
# ForeignKey to IntegerField given value 'abc'. The ForeignKey itself
# doesn't have validation for non-integers, so we must run validation
# using the target field.
if hasattr(self.lhs.output_field, 'get_path_info'):
# Run the target field's get_prep_value. We can safely assume there is
# only one as we don't get to the direct value branch otherwise.
target_field = self.lhs.output_field.get_path_info()[-1].target_fields[-1]
self.rhs = [target_field.get_prep_value(v) for v in self.rhs]
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
# For multicolumn lookups we need to build a multicolumn where clause.
# This clause is either a SubqueryConstraint (for values that need to be compiled to
# SQL) or an OR-combined list of (col1 = val1 AND col2 = val2 AND ...) clauses.
from django.db.models.sql.where import WhereNode, SubqueryConstraint, AND, OR
root_constraint = WhereNode(connector=OR)
if self.rhs_is_direct_value():
values = [get_normalized_value(value, self.lhs) for value in self.rhs]
for value in values:
value_constraint = WhereNode()
for source, target, val in zip(self.lhs.sources, self.lhs.targets, value):
lookup_class = target.get_lookup('exact')
lookup = lookup_class(target.get_col(self.lhs.alias, source), val)
value_constraint.add(lookup, AND)
root_constraint.add(value_constraint, OR)
else:
root_constraint.add(
SubqueryConstraint(
self.lhs.alias, [target.column for target in self.lhs.targets],
[source.name for source in self.lhs.sources], self.rhs),
AND)
return root_constraint.as_sql(compiler, connection)
else:
if (not getattr(self.rhs, 'has_select_fields', True) and
not getattr(self.lhs.field.target_field, 'primary_key', False)):
self.rhs.clear_select_clause()
if (getattr(self.lhs.output_field, 'primary_key', False) and
self.lhs.output_field.model == self.rhs.model):
# A case like Restaurant.objects.filter(place__in=restaurant_qs),
# where place is a OneToOneField and the primary key of
# Restaurant.
target_field = self.lhs.field.name
else:
target_field = self.lhs.field.target_field.name
self.rhs.add_fields([target_field], True)
return super().as_sql(compiler, connection)
class RelatedLookupMixin:
def get_prep_lookup(self):
if not isinstance(self.lhs, MultiColSource) and self.rhs_is_direct_value():
# If we get here, we are dealing with single-column relations.
self.rhs = get_normalized_value(self.rhs, self.lhs)[0]
# We need to run the related field's get_prep_value(). Consider case
# ForeignKey to IntegerField given value 'abc'. The ForeignKey itself
# doesn't have validation for non-integers, so we must run validation
# using the target field.
if self.prepare_rhs and hasattr(self.lhs.output_field, 'get_path_info'):
# Get the target field. We can safely assume there is only one
# as we don't get to the direct value branch otherwise.
target_field = self.lhs.output_field.get_path_info()[-1].target_fields[-1]
self.rhs = target_field.get_prep_value(self.rhs)
return super().get_prep_lookup()
def as_sql(self, compiler, connection):
if isinstance(self.lhs, MultiColSource):
assert self.rhs_is_direct_value()
self.rhs = get_normalized_value(self.rhs, self.lhs)
from django.db.models.sql.where import WhereNode, AND
root_constraint = WhereNode()
for target, source, val in zip(self.lhs.targets, self.lhs.sources, self.rhs):
lookup_class = target.get_lookup(self.lookup_name)
root_constraint.add(
lookup_class(target.get_col(self.lhs.alias, source), val), AND)
return root_constraint.as_sql(compiler, connection)
return super().as_sql(compiler, connection)
class RelatedExact(RelatedLookupMixin, Exact):
pass
class RelatedLessThan(RelatedLookupMixin, LessThan):
pass
class RelatedGreaterThan(RelatedLookupMixin, GreaterThan):
pass
class RelatedGreaterThanOrEqual(RelatedLookupMixin, GreaterThanOrEqual):
pass
class RelatedLessThanOrEqual(RelatedLookupMixin, LessThanOrEqual):
pass
class RelatedIsNull(RelatedLookupMixin, IsNull):
pass
|
7dc276775662634b04a2e4aaf5257b5b57e6e5e1370bf9cc1a4cb731adf8edd9 | """
Field-like classes that aren't really fields. It's easier to use objects that
have the same attributes as fields sometimes (avoids a lot of special casing).
"""
from django.db.models import fields
class OrderWrt(fields.IntegerField):
"""
A proxy for the _order database field that is used when
Meta.order_with_respect_to is specified.
"""
def __init__(self, *args, **kwargs):
kwargs['name'] = '_order'
kwargs['editable'] = False
super().__init__(*args, **kwargs)
|
0cb17b964dde645db0b03c241695e12c452e28485769f5117f6efba86b14935f | import collections.abc
import copy
import datetime
import decimal
import operator
import uuid
import warnings
from base64 import b64decode, b64encode
from functools import partialmethod, total_ordering
from django import forms
from django.apps import apps
from django.conf import settings
from django.core import checks, exceptions, validators
# When the _meta object was formalized, this exception was moved to
# django.core.exceptions. It is retained here for backwards compatibility
# purposes.
from django.core.exceptions import FieldDoesNotExist # NOQA
from django.db import connection, connections, router
from django.db.models.constants import LOOKUP_SEP
from django.db.models.query_utils import DeferredAttribute, RegisterLookupMixin
from django.utils import timezone
from django.utils.datastructures import DictWrapper
from django.utils.dateparse import (
parse_date, parse_datetime, parse_duration, parse_time,
)
from django.utils.duration import duration_microseconds, duration_string
from django.utils.encoding import force_bytes, smart_text
from django.utils.functional import Promise, cached_property
from django.utils.ipv6 import clean_ipv6_address
from django.utils.itercompat import is_iterable
from django.utils.text import capfirst
from django.utils.translation import gettext_lazy as _
__all__ = [
'AutoField', 'BLANK_CHOICE_DASH', 'BigAutoField', 'BigIntegerField',
'BinaryField', 'BooleanField', 'CharField', 'CommaSeparatedIntegerField',
'DateField', 'DateTimeField', 'DecimalField', 'DurationField',
'EmailField', 'Empty', 'Field', 'FieldDoesNotExist', 'FilePathField',
'FloatField', 'GenericIPAddressField', 'IPAddressField', 'IntegerField',
'NOT_PROVIDED', 'NullBooleanField', 'PositiveIntegerField',
'PositiveSmallIntegerField', 'SlugField', 'SmallIntegerField', 'TextField',
'TimeField', 'URLField', 'UUIDField',
]
class Empty:
pass
class NOT_PROVIDED:
pass
# The values to use for "blank" in SelectFields. Will be appended to the start
# of most "choices" lists.
BLANK_CHOICE_DASH = [("", "---------")]
def _load_field(app_label, model_name, field_name):
return apps.get_model(app_label, model_name)._meta.get_field(field_name)
# A guide to Field parameters:
#
# * name: The name of the field specified in the model.
# * attname: The attribute to use on the model object. This is the same as
# "name", except in the case of ForeignKeys, where "_id" is
# appended.
# * db_column: The db_column specified in the model (or None).
# * column: The database column for this field. This is the same as
# "attname", except if db_column is specified.
#
# Code that introspects values, or does other dynamic things, should use
# attname. For example, this gets the primary key value of object "obj":
#
# getattr(obj, opts.pk.attname)
def _empty(of_cls):
new = Empty()
new.__class__ = of_cls
return new
def return_None():
return None
@total_ordering
class Field(RegisterLookupMixin):
"""Base class for all field types"""
# Designates whether empty strings fundamentally are allowed at the
# database level.
empty_strings_allowed = True
empty_values = list(validators.EMPTY_VALUES)
# These track each time a Field instance is created. Used to retain order.
# The auto_creation_counter is used for fields that Django implicitly
# creates, creation_counter is used for all user-specified fields.
creation_counter = 0
auto_creation_counter = -1
default_validators = [] # Default set of validators
default_error_messages = {
'invalid_choice': _('Value %(value)r is not a valid choice.'),
'null': _('This field cannot be null.'),
'blank': _('This field cannot be blank.'),
'unique': _('%(model_name)s with this %(field_label)s '
'already exists.'),
# Translators: The 'lookup_type' is one of 'date', 'year' or 'month'.
# Eg: "Title must be unique for pub_date year"
'unique_for_date': _("%(field_label)s must be unique for "
"%(date_field_label)s %(lookup_type)s."),
}
system_check_deprecated_details = None
system_check_removed_details = None
# Field flags
hidden = False
many_to_many = None
many_to_one = None
one_to_many = None
one_to_one = None
related_model = None
# Generic field type description, usually overridden by subclasses
def _description(self):
return _('Field of type: %(field_type)s') % {
'field_type': self.__class__.__name__
}
description = property(_description)
def __init__(self, verbose_name=None, name=None, primary_key=False,
max_length=None, unique=False, blank=False, null=False,
db_index=False, rel=None, default=NOT_PROVIDED, editable=True,
serialize=True, unique_for_date=None, unique_for_month=None,
unique_for_year=None, choices=None, help_text='', db_column=None,
db_tablespace=None, auto_created=False, validators=(),
error_messages=None):
self.name = name
self.verbose_name = verbose_name # May be set by set_attributes_from_name
self._verbose_name = verbose_name # Store original for deconstruction
self.primary_key = primary_key
self.max_length, self._unique = max_length, unique
self.blank, self.null = blank, null
self.remote_field = rel
self.is_relation = self.remote_field is not None
self.default = default
self.editable = editable
self.serialize = serialize
self.unique_for_date = unique_for_date
self.unique_for_month = unique_for_month
self.unique_for_year = unique_for_year
if isinstance(choices, collections.abc.Iterator):
choices = list(choices)
self.choices = choices or []
self.help_text = help_text
self.db_index = db_index
self.db_column = db_column
self._db_tablespace = db_tablespace
self.auto_created = auto_created
# Adjust the appropriate creation counter, and save our local copy.
if auto_created:
self.creation_counter = Field.auto_creation_counter
Field.auto_creation_counter -= 1
else:
self.creation_counter = Field.creation_counter
Field.creation_counter += 1
self._validators = list(validators) # Store for deconstruction later
messages = {}
for c in reversed(self.__class__.__mro__):
messages.update(getattr(c, 'default_error_messages', {}))
messages.update(error_messages or {})
self._error_messages = error_messages # Store for deconstruction later
self.error_messages = messages
def __str__(self):
"""
Return "app_label.model_label.field_name" for fields attached to
models.
"""
if not hasattr(self, 'model'):
return super().__str__()
model = self.model
app = model._meta.app_label
return '%s.%s.%s' % (app, model._meta.object_name, self.name)
def __repr__(self):
"""Display the module, class, and name of the field."""
path = '%s.%s' % (self.__class__.__module__, self.__class__.__qualname__)
name = getattr(self, 'name', None)
if name is not None:
return '<%s: %s>' % (path, name)
return '<%s>' % path
def check(self, **kwargs):
return [
*self._check_field_name(),
*self._check_choices(),
*self._check_db_index(),
*self._check_null_allowed_for_primary_keys(),
*self._check_backend_specific_checks(**kwargs),
*self._check_validators(),
*self._check_deprecation_details(),
]
def _check_field_name(self):
"""
Check if field name is valid, i.e. 1) does not end with an
underscore, 2) does not contain "__" and 3) is not "pk".
"""
if self.name.endswith('_'):
return [
checks.Error(
'Field names must not end with an underscore.',
obj=self,
id='fields.E001',
)
]
elif LOOKUP_SEP in self.name:
return [
checks.Error(
'Field names must not contain "%s".' % (LOOKUP_SEP,),
obj=self,
id='fields.E002',
)
]
elif self.name == 'pk':
return [
checks.Error(
"'pk' is a reserved word that cannot be used as a field name.",
obj=self,
id='fields.E003',
)
]
else:
return []
def _check_choices(self):
if not self.choices:
return []
def is_value(value, accept_promise=True):
return isinstance(value, (str, Promise) if accept_promise else str) or not is_iterable(value)
if is_value(self.choices, accept_promise=False):
return [
checks.Error(
"'choices' must be an iterable (e.g., a list or tuple).",
obj=self,
id='fields.E004',
)
]
# Expect [group_name, [value, display]]
for choices_group in self.choices:
try:
group_name, group_choices = choices_group
except ValueError:
# Containing non-pairs
break
try:
if not all(
is_value(value) and is_value(human_name)
for value, human_name in group_choices
):
break
except (TypeError, ValueError):
# No groups, choices in the form [value, display]
value, human_name = group_name, group_choices
if not is_value(value) or not is_value(human_name):
break
# Special case: choices=['ab']
if isinstance(choices_group, str):
break
else:
return []
return [
checks.Error(
"'choices' must be an iterable containing "
"(actual value, human readable name) tuples.",
obj=self,
id='fields.E005',
)
]
def _check_db_index(self):
if self.db_index not in (None, True, False):
return [
checks.Error(
"'db_index' must be None, True or False.",
obj=self,
id='fields.E006',
)
]
else:
return []
def _check_null_allowed_for_primary_keys(self):
if (self.primary_key and self.null and
not connection.features.interprets_empty_strings_as_nulls):
# We cannot reliably check this for backends like Oracle which
# consider NULL and '' to be equal (and thus set up
# character-based fields a little differently).
return [
checks.Error(
'Primary keys must not have null=True.',
hint=('Set null=False on the field, or '
'remove primary_key=True argument.'),
obj=self,
id='fields.E007',
)
]
else:
return []
def _check_backend_specific_checks(self, **kwargs):
app_label = self.model._meta.app_label
for db in connections:
if router.allow_migrate(db, app_label, model_name=self.model._meta.model_name):
return connections[db].validation.check_field(self, **kwargs)
return []
def _check_validators(self):
errors = []
for i, validator in enumerate(self.validators):
if not callable(validator):
errors.append(
checks.Error(
"All 'validators' must be callable.",
hint=(
"validators[{i}] ({repr}) isn't a function or "
"instance of a validator class.".format(
i=i, repr=repr(validator),
)
),
obj=self,
id='fields.E008',
)
)
return errors
def _check_deprecation_details(self):
if self.system_check_removed_details is not None:
return [
checks.Error(
self.system_check_removed_details.get(
'msg',
'%s has been removed except for support in historical '
'migrations.' % self.__class__.__name__
),
hint=self.system_check_removed_details.get('hint'),
obj=self,
id=self.system_check_removed_details.get('id', 'fields.EXXX'),
)
]
elif self.system_check_deprecated_details is not None:
return [
checks.Warning(
self.system_check_deprecated_details.get(
'msg',
'%s has been deprecated.' % self.__class__.__name__
),
hint=self.system_check_deprecated_details.get('hint'),
obj=self,
id=self.system_check_deprecated_details.get('id', 'fields.WXXX'),
)
]
return []
def get_col(self, alias, output_field=None):
if output_field is None:
output_field = self
if alias != self.model._meta.db_table or output_field != self:
from django.db.models.expressions import Col
return Col(alias, self, output_field)
else:
return self.cached_col
@cached_property
def cached_col(self):
from django.db.models.expressions import Col
return Col(self.model._meta.db_table, self)
def select_format(self, compiler, sql, params):
"""
Custom format for select clauses. For example, GIS columns need to be
selected as AsText(table.col) on MySQL as the table.col data can't be
used by Django.
"""
return sql, params
def deconstruct(self):
"""
Return enough information to recreate the field as a 4-tuple:
* The name of the field on the model, if contribute_to_class() has
been run.
* The import path of the field, including the class:e.g.
django.db.models.IntegerField This should be the most portable
version, so less specific may be better.
* A list of positional arguments.
* A dict of keyword arguments.
Note that the positional or keyword arguments must contain values of
the following types (including inner values of collection types):
* None, bool, str, int, float, complex, set, frozenset, list, tuple,
dict
* UUID
* datetime.datetime (naive), datetime.date
* top-level classes, top-level functions - will be referenced by their
full import path
* Storage instances - these have their own deconstruct() method
This is because the values here must be serialized into a text format
(possibly new Python code, possibly JSON) and these are the only types
with encoding handlers defined.
There's no need to return the exact way the field was instantiated this
time, just ensure that the resulting field is the same - prefer keyword
arguments over positional ones, and omit parameters with their default
values.
"""
# Short-form way of fetching all the default parameters
keywords = {}
possibles = {
"verbose_name": None,
"primary_key": False,
"max_length": None,
"unique": False,
"blank": False,
"null": False,
"db_index": False,
"default": NOT_PROVIDED,
"editable": True,
"serialize": True,
"unique_for_date": None,
"unique_for_month": None,
"unique_for_year": None,
"choices": [],
"help_text": '',
"db_column": None,
"db_tablespace": None,
"auto_created": False,
"validators": [],
"error_messages": None,
}
attr_overrides = {
"unique": "_unique",
"error_messages": "_error_messages",
"validators": "_validators",
"verbose_name": "_verbose_name",
"db_tablespace": "_db_tablespace",
}
equals_comparison = {"choices", "validators"}
for name, default in possibles.items():
value = getattr(self, attr_overrides.get(name, name))
# Unroll anything iterable for choices into a concrete list
if name == "choices" and isinstance(value, collections.abc.Iterable):
value = list(value)
# Do correct kind of comparison
if name in equals_comparison:
if value != default:
keywords[name] = value
else:
if value is not default:
keywords[name] = value
# Work out path - we shorten it for known Django core fields
path = "%s.%s" % (self.__class__.__module__, self.__class__.__qualname__)
if path.startswith("django.db.models.fields.related"):
path = path.replace("django.db.models.fields.related", "django.db.models")
if path.startswith("django.db.models.fields.files"):
path = path.replace("django.db.models.fields.files", "django.db.models")
if path.startswith("django.db.models.fields.proxy"):
path = path.replace("django.db.models.fields.proxy", "django.db.models")
if path.startswith("django.db.models.fields"):
path = path.replace("django.db.models.fields", "django.db.models")
# Return basic info - other fields should override this.
return (self.name, path, [], keywords)
def clone(self):
"""
Uses deconstruct() to clone a new copy of this Field.
Will not preserve any class attachments/attribute names.
"""
name, path, args, kwargs = self.deconstruct()
return self.__class__(*args, **kwargs)
def __eq__(self, other):
# Needed for @total_ordering
if isinstance(other, Field):
return self.creation_counter == other.creation_counter
return NotImplemented
def __lt__(self, other):
# This is needed because bisect does not take a comparison function.
if isinstance(other, Field):
return self.creation_counter < other.creation_counter
return NotImplemented
def __hash__(self):
return hash(self.creation_counter)
def __deepcopy__(self, memodict):
# We don't have to deepcopy very much here, since most things are not
# intended to be altered after initial creation.
obj = copy.copy(self)
if self.remote_field:
obj.remote_field = copy.copy(self.remote_field)
if hasattr(self.remote_field, 'field') and self.remote_field.field is self:
obj.remote_field.field = obj
memodict[id(self)] = obj
return obj
def __copy__(self):
# We need to avoid hitting __reduce__, so define this
# slightly weird copy construct.
obj = Empty()
obj.__class__ = self.__class__
obj.__dict__ = self.__dict__.copy()
return obj
def __reduce__(self):
"""
Pickling should return the model._meta.fields instance of the field,
not a new copy of that field. So, use the app registry to load the
model and then the field back.
"""
if not hasattr(self, 'model'):
# Fields are sometimes used without attaching them to models (for
# example in aggregation). In this case give back a plain field
# instance. The code below will create a new empty instance of
# class self.__class__, then update its dict with self.__dict__
# values - so, this is very close to normal pickle.
state = self.__dict__.copy()
# The _get_default cached_property can't be pickled due to lambda
# usage.
state.pop('_get_default', None)
return _empty, (self.__class__,), state
return _load_field, (self.model._meta.app_label, self.model._meta.object_name,
self.name)
def get_pk_value_on_save(self, instance):
"""
Hook to generate new PK values on save. This method is called when
saving instances with no primary key value set. If this method returns
something else than None, then the returned value is used when saving
the new instance.
"""
if self.default:
return self.get_default()
return None
def to_python(self, value):
"""
Convert the input value into the expected Python data type, raising
django.core.exceptions.ValidationError if the data can't be converted.
Return the converted value. Subclasses should override this.
"""
return value
@cached_property
def validators(self):
"""
Some validators can't be created at field initialization time.
This method provides a way to delay their creation until required.
"""
return [*self.default_validators, *self._validators]
def run_validators(self, value):
if value in self.empty_values:
return
errors = []
for v in self.validators:
try:
v(value)
except exceptions.ValidationError as e:
if hasattr(e, 'code') and e.code in self.error_messages:
e.message = self.error_messages[e.code]
errors.extend(e.error_list)
if errors:
raise exceptions.ValidationError(errors)
def validate(self, value, model_instance):
"""
Validate value and raise ValidationError if necessary. Subclasses
should override this to provide validation logic.
"""
if not self.editable:
# Skip validation for non-editable fields.
return
if self.choices and value not in self.empty_values:
for option_key, option_value in self.choices:
if isinstance(option_value, (list, tuple)):
# This is an optgroup, so look inside the group for
# options.
for optgroup_key, optgroup_value in option_value:
if value == optgroup_key:
return
elif value == option_key:
return
raise exceptions.ValidationError(
self.error_messages['invalid_choice'],
code='invalid_choice',
params={'value': value},
)
if value is None and not self.null:
raise exceptions.ValidationError(self.error_messages['null'], code='null')
if not self.blank and value in self.empty_values:
raise exceptions.ValidationError(self.error_messages['blank'], code='blank')
def clean(self, value, model_instance):
"""
Convert the value's type and run validation. Validation errors
from to_python() and validate() are propagated. Return the correct
value if no error is raised.
"""
value = self.to_python(value)
self.validate(value, model_instance)
self.run_validators(value)
return value
def db_type_parameters(self, connection):
return DictWrapper(self.__dict__, connection.ops.quote_name, 'qn_')
def db_check(self, connection):
"""
Return the database column check constraint for this field, for the
provided connection. Works the same way as db_type() for the case that
get_internal_type() does not map to a preexisting model field.
"""
data = self.db_type_parameters(connection)
try:
return connection.data_type_check_constraints[self.get_internal_type()] % data
except KeyError:
return None
def db_type(self, connection):
"""
Return the database column data type for this field, for the provided
connection.
"""
# The default implementation of this method looks at the
# backend-specific data_types dictionary, looking up the field by its
# "internal type".
#
# A Field class can implement the get_internal_type() method to specify
# which *preexisting* Django Field class it's most similar to -- i.e.,
# a custom field might be represented by a TEXT column type, which is
# the same as the TextField Django field type, which means the custom
# field's get_internal_type() returns 'TextField'.
#
# But the limitation of the get_internal_type() / data_types approach
# is that it cannot handle database column types that aren't already
# mapped to one of the built-in Django field types. In this case, you
# can implement db_type() instead of get_internal_type() to specify
# exactly which wacky database column type you want to use.
data = self.db_type_parameters(connection)
try:
return connection.data_types[self.get_internal_type()] % data
except KeyError:
return None
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. For example, this method is called by ForeignKey and OneToOneField
to determine its data type.
"""
return self.db_type(connection)
def cast_db_type(self, connection):
"""Return the data type to use in the Cast() function."""
db_type = connection.ops.cast_data_types.get(self.get_internal_type())
if db_type:
return db_type % self.db_type_parameters(connection)
return self.db_type(connection)
def db_parameters(self, connection):
"""
Extension of db_type(), providing a range of different return values
(type, checks). This will look at db_type(), allowing custom model
fields to override it.
"""
type_string = self.db_type(connection)
check_string = self.db_check(connection)
return {
"type": type_string,
"check": check_string,
}
def db_type_suffix(self, connection):
return connection.data_types_suffix.get(self.get_internal_type())
def get_db_converters(self, connection):
if hasattr(self, 'from_db_value'):
return [self.from_db_value]
return []
@property
def unique(self):
return self._unique or self.primary_key
@property
def db_tablespace(self):
return self._db_tablespace or settings.DEFAULT_INDEX_TABLESPACE
def set_attributes_from_name(self, name):
self.name = self.name or name
self.attname, self.column = self.get_attname_column()
self.concrete = self.column is not None
if self.verbose_name is None and self.name:
self.verbose_name = self.name.replace('_', ' ')
def contribute_to_class(self, cls, name, private_only=False):
"""
Register the field with the model class it belongs to.
If private_only is True, create a separate instance of this field
for every subclass of cls, even if cls is not an abstract model.
"""
self.set_attributes_from_name(name)
self.model = cls
if private_only:
cls._meta.add_field(self, private=True)
else:
cls._meta.add_field(self)
if self.column:
# Don't override classmethods with the descriptor. This means that
# if you have a classmethod and a field with the same name, then
# such fields can't be deferred (we don't have a check for this).
if not getattr(cls, self.attname, None):
setattr(cls, self.attname, DeferredAttribute(self.attname))
if self.choices:
setattr(cls, 'get_%s_display' % self.name,
partialmethod(cls._get_FIELD_display, field=self))
def get_filter_kwargs_for_object(self, obj):
"""
Return a dict that when passed as kwargs to self.model.filter(), would
yield all instances having the same value for this field as obj has.
"""
return {self.name: getattr(obj, self.attname)}
def get_attname(self):
return self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_internal_type(self):
return self.__class__.__name__
def pre_save(self, model_instance, add):
"""Return field's value just before saving."""
return getattr(model_instance, self.attname)
def get_prep_value(self, value):
"""Perform preliminary non-db specific value checks and conversions."""
if isinstance(value, Promise):
value = value._proxy____cast()
return value
def get_db_prep_value(self, value, connection, prepared=False):
"""
Return field's value prepared for interacting with the database backend.
Used by the default implementations of get_db_prep_save().
"""
if not prepared:
value = self.get_prep_value(value)
return value
def get_db_prep_save(self, value, connection):
"""Return field's value prepared for saving into a database."""
return self.get_db_prep_value(value, connection=connection, prepared=False)
def has_default(self):
"""Return a boolean of whether this field has a default value."""
return self.default is not NOT_PROVIDED
def get_default(self):
"""Return the default value for this field."""
return self._get_default()
@cached_property
def _get_default(self):
if self.has_default():
if callable(self.default):
return self.default
return lambda: self.default
if not self.empty_strings_allowed or self.null and not connection.features.interprets_empty_strings_as_nulls:
return return_None
return str # return empty string
def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH, limit_choices_to=None):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
"""
if self.choices:
choices = list(self.choices)
if include_blank:
blank_defined = any(choice in ('', None) for choice, _ in self.flatchoices)
if not blank_defined:
choices = blank_choice + choices
return choices
rel_model = self.remote_field.model
limit_choices_to = limit_choices_to or self.get_limit_choices_to()
choice_func = operator.attrgetter(
self.remote_field.get_related_field().attname
if hasattr(self.remote_field, 'get_related_field')
else 'pk'
)
return (blank_choice if include_blank else []) + [
(choice_func(x), smart_text(x))
for x in rel_model._default_manager.complex_filter(limit_choices_to)
]
def value_to_string(self, obj):
"""
Return a string value of this field from the passed obj.
This is used by the serialization framework.
"""
return str(self.value_from_object(obj))
def _get_flatchoices(self):
"""Flattened version of choices tuple."""
flat = []
for choice, value in self.choices:
if isinstance(value, (list, tuple)):
flat.extend(value)
else:
flat.append((choice, value))
return flat
flatchoices = property(_get_flatchoices)
def save_form_data(self, instance, data):
setattr(instance, self.name, data)
def formfield(self, form_class=None, choices_form_class=None, **kwargs):
"""Return a django.forms.Field instance for this field."""
defaults = {'required': not self.blank,
'label': capfirst(self.verbose_name),
'help_text': self.help_text}
if self.has_default():
if callable(self.default):
defaults['initial'] = self.default
defaults['show_hidden_initial'] = True
else:
defaults['initial'] = self.get_default()
if self.choices:
# Fields with choices get special treatment.
include_blank = (self.blank or
not (self.has_default() or 'initial' in kwargs))
defaults['choices'] = self.get_choices(include_blank=include_blank)
defaults['coerce'] = self.to_python
if self.null:
defaults['empty_value'] = None
if choices_form_class is not None:
form_class = choices_form_class
else:
form_class = forms.TypedChoiceField
# Many of the subclass-specific formfield arguments (min_value,
# max_value) don't apply for choice fields, so be sure to only pass
# the values that TypedChoiceField will understand.
for k in list(kwargs):
if k not in ('coerce', 'empty_value', 'choices', 'required',
'widget', 'label', 'initial', 'help_text',
'error_messages', 'show_hidden_initial', 'disabled'):
del kwargs[k]
defaults.update(kwargs)
if form_class is None:
form_class = forms.CharField
return form_class(**defaults)
def value_from_object(self, obj):
"""Return the value of this field in the given model instance."""
return getattr(obj, self.attname)
class AutoField(Field):
description = _("Integer")
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value must be an integer."),
}
def __init__(self, *args, **kwargs):
kwargs['blank'] = True
super().__init__(*args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
]
def _check_primary_key(self):
if not self.primary_key:
return [
checks.Error(
'AutoFields must set primary_key=True.',
obj=self,
id='fields.E100',
),
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['blank']
kwargs['primary_key'] = True
return name, path, args, kwargs
def get_internal_type(self):
return "AutoField"
def to_python(self, value):
if value is None:
return value
try:
return int(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def rel_db_type(self, connection):
return IntegerField().db_type(connection=connection)
def validate(self, value, model_instance):
pass
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
value = connection.ops.validate_autopk_value(value)
return value
def get_prep_value(self, value):
from django.db.models.expressions import OuterRef
value = super().get_prep_value(value)
if value is None or isinstance(value, OuterRef):
return value
return int(value)
def contribute_to_class(self, cls, name, **kwargs):
assert not cls._meta.auto_field, "Model %s can't have more than one AutoField." % cls._meta.label
super().contribute_to_class(cls, name, **kwargs)
cls._meta.auto_field = self
def formfield(self, **kwargs):
return None
class BigAutoField(AutoField):
description = _("Big (8 byte) integer")
def get_internal_type(self):
return "BigAutoField"
def rel_db_type(self, connection):
return BigIntegerField().db_type(connection=connection)
class BooleanField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value must be either True or False."),
'invalid_nullable': _("'%(value)s' value must be either True, False, or None."),
}
description = _("Boolean (Either True or False)")
def get_internal_type(self):
return "BooleanField"
def to_python(self, value):
if self.null and value in self.empty_values:
return None
if value in (True, False):
# if value is 1 or 0 than it's equal to True or False, but we want
# to return a true bool for semantic reasons.
return bool(value)
if value in ('t', 'True', '1'):
return True
if value in ('f', 'False', '0'):
return False
raise exceptions.ValidationError(
self.error_messages['invalid_nullable' if self.null else 'invalid'],
code='invalid',
params={'value': value},
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return self.to_python(value)
def formfield(self, **kwargs):
if self.choices:
include_blank = not (self.has_default() or 'initial' in kwargs)
defaults = {'choices': self.get_choices(include_blank=include_blank)}
else:
form_class = forms.NullBooleanField if self.null else forms.BooleanField
# In HTML checkboxes, 'required' means "must be checked" which is
# different from the choices case ("must select some value").
# required=False allows unchecked checkboxes.
defaults = {'form_class': form_class, 'required': False}
return super().formfield(**{**defaults, **kwargs})
class CharField(Field):
description = _("String (up to %(max_length)s)")
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.validators.append(validators.MaxLengthValidator(self.max_length))
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_max_length_attribute(**kwargs),
]
def _check_max_length_attribute(self, **kwargs):
if self.max_length is None:
return [
checks.Error(
"CharFields must define a 'max_length' attribute.",
obj=self,
id='fields.E120',
)
]
elif (not isinstance(self.max_length, int) or isinstance(self.max_length, bool) or
self.max_length <= 0):
return [
checks.Error(
"'max_length' must be a positive integer.",
obj=self,
id='fields.E121',
)
]
else:
return []
def cast_db_type(self, connection):
if self.max_length is None:
return connection.ops.cast_char_field_without_max_length
return super().cast_db_type(connection)
def get_internal_type(self):
return "CharField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
defaults = {'max_length': self.max_length}
# TODO: Handle multiple backends with different feature flags.
if self.null and not connection.features.interprets_empty_strings_as_nulls:
defaults['empty_value'] = None
defaults.update(kwargs)
return super().formfield(**defaults)
class CommaSeparatedIntegerField(CharField):
default_validators = [validators.validate_comma_separated_integer_list]
description = _("Comma-separated integers")
system_check_removed_details = {
'msg': (
'CommaSeparatedIntegerField is removed except for support in '
'historical migrations.'
),
'hint': (
'Use CharField(validators=[validate_comma_separated_integer_list]) '
'instead.'
),
'id': 'fields.E901',
}
class DateTimeCheckMixin:
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_mutually_exclusive_options(),
*self._check_fix_default_value(),
]
def _check_mutually_exclusive_options(self):
# auto_now, auto_now_add, and default are mutually exclusive
# options. The use of more than one of these options together
# will trigger an Error
mutually_exclusive_options = [self.auto_now_add, self.auto_now, self.has_default()]
enabled_options = [option not in (None, False) for option in mutually_exclusive_options].count(True)
if enabled_options > 1:
return [
checks.Error(
"The options auto_now, auto_now_add, and default "
"are mutually exclusive. Only one of these options "
"may be present.",
obj=self,
id='fields.E160',
)
]
else:
return []
def _check_fix_default_value(self):
return []
class DateField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value has an invalid date format. It must be "
"in YYYY-MM-DD format."),
'invalid_date': _("'%(value)s' value has the correct format (YYYY-MM-DD) "
"but it is an invalid date."),
}
description = _("Date (without time)")
def __init__(self, verbose_name=None, name=None, auto_now=False,
auto_now_add=False, **kwargs):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs['editable'] = False
kwargs['blank'] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
now = timezone.now()
if not timezone.is_naive(now):
now = timezone.make_naive(now, timezone.utc)
value = self.default
if isinstance(value, datetime.datetime):
if not timezone.is_naive(value):
value = timezone.make_naive(value, timezone.utc)
value = value.date()
elif isinstance(value, datetime.date):
# Nothing to do, as dates don't have tz information
pass
else:
# No explicit date / datetime value -- no checks necessary
return []
offset = datetime.timedelta(days=1)
lower = (now - offset).date()
upper = (now + offset).date()
if lower <= value <= upper:
return [
checks.Warning(
'Fixed default value provided.',
hint='It seems you set a fixed date / time / datetime '
'value as default for this field. This may not be '
'what you want. If you want to have the current date '
'as default, use `django.utils.timezone.now`',
obj=self,
id='fields.W161',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now:
kwargs['auto_now'] = True
if self.auto_now_add:
kwargs['auto_now_add'] = True
if self.auto_now or self.auto_now_add:
del kwargs['editable']
del kwargs['blank']
return name, path, args, kwargs
def get_internal_type(self):
return "DateField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
if settings.USE_TZ and timezone.is_aware(value):
# Convert aware datetimes to the default time zone
# before casting them to dates (#17742).
default_timezone = timezone.get_default_timezone()
value = timezone.make_naive(value, default_timezone)
return value.date()
if isinstance(value, datetime.date):
return value
try:
parsed = parse_date(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_date'],
code='invalid_date',
params={'value': value},
)
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.date.today()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
if not self.null:
setattr(
cls, 'get_next_by_%s' % self.name,
partialmethod(cls._get_next_or_previous_by_FIELD, field=self, is_next=True)
)
setattr(
cls, 'get_previous_by_%s' % self.name,
partialmethod(cls._get_next_or_previous_by_FIELD, field=self, is_next=False)
)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts dates into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.DateField,
**kwargs,
})
class DateTimeField(DateField):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value has an invalid format. It must be in "
"YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ] format."),
'invalid_date': _("'%(value)s' value has the correct format "
"(YYYY-MM-DD) but it is an invalid date."),
'invalid_datetime': _("'%(value)s' value has the correct format "
"(YYYY-MM-DD HH:MM[:ss[.uuuuuu]][TZ]) "
"but it is an invalid date/time."),
}
description = _("Date (with time)")
# __init__ is inherited from DateField
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
now = timezone.now()
if not timezone.is_naive(now):
now = timezone.make_naive(now, timezone.utc)
value = self.default
if isinstance(value, datetime.datetime):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
upper = now + second_offset
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc)
elif isinstance(value, datetime.date):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
lower = datetime.datetime(lower.year, lower.month, lower.day)
upper = now + second_offset
upper = datetime.datetime(upper.year, upper.month, upper.day)
value = datetime.datetime(value.year, value.month, value.day)
else:
# No explicit date / datetime value -- no checks necessary
return []
if lower <= value <= upper:
return [
checks.Warning(
'Fixed default value provided.',
hint='It seems you set a fixed date / time / datetime '
'value as default for this field. This may not be '
'what you want. If you want to have the current date '
'as default, use `django.utils.timezone.now`',
obj=self,
id='fields.W161',
)
]
return []
def get_internal_type(self):
return "DateTimeField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.datetime):
return value
if isinstance(value, datetime.date):
value = datetime.datetime(value.year, value.month, value.day)
if settings.USE_TZ:
# For backwards compatibility, interpret naive datetimes in
# local time. This won't work during DST change, but we can't
# do much about it, so we let the exceptions percolate up the
# call stack.
warnings.warn("DateTimeField %s.%s received a naive datetime "
"(%s) while time zone support is active." %
(self.model.__name__, self.name, value),
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
try:
parsed = parse_datetime(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_datetime'],
code='invalid_datetime',
params={'value': value},
)
try:
parsed = parse_date(value)
if parsed is not None:
return datetime.datetime(parsed.year, parsed.month, parsed.day)
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_date'],
code='invalid_date',
params={'value': value},
)
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = timezone.now()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
# contribute_to_class is inherited from DateField, it registers
# get_next_by_FOO and get_prev_by_FOO
def get_prep_value(self, value):
value = super().get_prep_value(value)
value = self.to_python(value)
if value is not None and settings.USE_TZ and timezone.is_naive(value):
# For backwards compatibility, interpret naive datetimes in local
# time. This won't work during DST change, but we can't do much
# about it, so we let the exceptions percolate up the call stack.
try:
name = '%s.%s' % (self.model.__name__, self.name)
except AttributeError:
name = '(unbound)'
warnings.warn("DateTimeField %s received a naive datetime (%s)"
" while time zone support is active." %
(name, value),
RuntimeWarning)
default_timezone = timezone.get_default_timezone()
value = timezone.make_aware(value, default_timezone)
return value
def get_db_prep_value(self, value, connection, prepared=False):
# Casts datetimes into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_datetimefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.DateTimeField,
**kwargs,
})
class DecimalField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value must be a decimal number."),
}
description = _("Decimal number")
def __init__(self, verbose_name=None, name=None, max_digits=None,
decimal_places=None, **kwargs):
self.max_digits, self.decimal_places = max_digits, decimal_places
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
errors = super().check(**kwargs)
digits_errors = [
*self._check_decimal_places(),
*self._check_max_digits(),
]
if not digits_errors:
errors.extend(self._check_decimal_places_and_max_digits(**kwargs))
else:
errors.extend(digits_errors)
return errors
def _check_decimal_places(self):
try:
decimal_places = int(self.decimal_places)
if decimal_places < 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'decimal_places' attribute.",
obj=self,
id='fields.E130',
)
]
except ValueError:
return [
checks.Error(
"'decimal_places' must be a non-negative integer.",
obj=self,
id='fields.E131',
)
]
else:
return []
def _check_max_digits(self):
try:
max_digits = int(self.max_digits)
if max_digits <= 0:
raise ValueError()
except TypeError:
return [
checks.Error(
"DecimalFields must define a 'max_digits' attribute.",
obj=self,
id='fields.E132',
)
]
except ValueError:
return [
checks.Error(
"'max_digits' must be a positive integer.",
obj=self,
id='fields.E133',
)
]
else:
return []
def _check_decimal_places_and_max_digits(self, **kwargs):
if int(self.decimal_places) > int(self.max_digits):
return [
checks.Error(
"'max_digits' must be greater or equal to 'decimal_places'.",
obj=self,
id='fields.E134',
)
]
return []
@cached_property
def validators(self):
return super().validators + [
validators.DecimalValidator(self.max_digits, self.decimal_places)
]
@cached_property
def context(self):
return decimal.Context(prec=self.max_digits)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.max_digits is not None:
kwargs['max_digits'] = self.max_digits
if self.decimal_places is not None:
kwargs['decimal_places'] = self.decimal_places
return name, path, args, kwargs
def get_internal_type(self):
return "DecimalField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, float):
return self.context.create_decimal_from_float(value)
try:
return decimal.Decimal(value)
except decimal.InvalidOperation:
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def get_db_prep_save(self, value, connection):
return connection.ops.adapt_decimalfield_value(self.to_python(value), self.max_digits, self.decimal_places)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
return super().formfield(**{
'max_digits': self.max_digits,
'decimal_places': self.decimal_places,
'form_class': forms.DecimalField,
**kwargs,
})
class DurationField(Field):
"""
Store timedelta objects.
Use interval on PostgreSQL, INTERVAL DAY TO SECOND on Oracle, and bigint
of microseconds on other databases.
"""
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value has an invalid format. It must be in "
"[DD] [HH:[MM:]]ss[.uuuuuu] format.")
}
description = _("Duration")
def get_internal_type(self):
return "DurationField"
def to_python(self, value):
if value is None:
return value
if isinstance(value, datetime.timedelta):
return value
try:
parsed = parse_duration(value)
except ValueError:
pass
else:
if parsed is not None:
return parsed
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def get_db_prep_value(self, value, connection, prepared=False):
if connection.features.has_native_duration_field:
return value
if value is None:
return None
return duration_microseconds(value)
def get_db_converters(self, connection):
converters = []
if not connection.features.has_native_duration_field:
converters.append(connection.ops.convert_durationfield_value)
return converters + super().get_db_converters(connection)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else duration_string(val)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.DurationField,
**kwargs,
})
class EmailField(CharField):
default_validators = [validators.validate_email]
description = _("Email address")
def __init__(self, *args, **kwargs):
# max_length=254 to be compliant with RFCs 3696 and 5321
kwargs.setdefault('max_length', 254)
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# We do not exclude max_length if it matches default as we want to change
# the default in future.
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause email validation to be performed
# twice.
return super().formfield(**{
'form_class': forms.EmailField,
**kwargs,
})
class FilePathField(Field):
description = _("File path")
def __init__(self, verbose_name=None, name=None, path='', match=None,
recursive=False, allow_files=True, allow_folders=False, **kwargs):
self.path, self.match, self.recursive = path, match, recursive
self.allow_files, self.allow_folders = allow_files, allow_folders
kwargs.setdefault('max_length', 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_allowing_files_or_folders(**kwargs),
]
def _check_allowing_files_or_folders(self, **kwargs):
if not self.allow_files and not self.allow_folders:
return [
checks.Error(
"FilePathFields must have either 'allow_files' or 'allow_folders' set to True.",
obj=self,
id='fields.E140',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.path != '':
kwargs['path'] = self.path
if self.match is not None:
kwargs['match'] = self.match
if self.recursive is not False:
kwargs['recursive'] = self.recursive
if self.allow_files is not True:
kwargs['allow_files'] = self.allow_files
if self.allow_folders is not False:
kwargs['allow_folders'] = self.allow_folders
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def formfield(self, **kwargs):
return super().formfield(**{
'path': self.path,
'match': self.match,
'recursive': self.recursive,
'form_class': forms.FilePathField,
'allow_files': self.allow_files,
'allow_folders': self.allow_folders,
**kwargs,
})
def get_internal_type(self):
return "FilePathField"
class FloatField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value must be a float."),
}
description = _("Floating point number")
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return float(value)
def get_internal_type(self):
return "FloatField"
def to_python(self, value):
if value is None:
return value
try:
return float(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.FloatField,
**kwargs,
})
class IntegerField(Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value must be an integer."),
}
description = _("Integer")
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_max_length_warning(),
]
def _check_max_length_warning(self):
if self.max_length is not None:
return [
checks.Warning(
"'max_length' is ignored when used with IntegerField",
hint="Remove 'max_length' from field",
obj=self,
id='fields.W122',
)
]
return []
@cached_property
def validators(self):
# These validators can't be added at field initialization time since
# they're based on values retrieved from `connection`.
validators_ = super().validators
internal_type = self.get_internal_type()
min_value, max_value = connection.ops.integer_field_range(internal_type)
if (min_value is not None and not
any(isinstance(validator, validators.MinValueValidator) and
validator.limit_value >= min_value for validator in validators_)):
validators_.append(validators.MinValueValidator(min_value))
if (max_value is not None and not
any(isinstance(validator, validators.MaxValueValidator) and
validator.limit_value <= max_value for validator in validators_)):
validators_.append(validators.MaxValueValidator(max_value))
return validators_
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return int(value)
def get_internal_type(self):
return "IntegerField"
def to_python(self, value):
if value is None:
return value
try:
return int(value)
except (TypeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.IntegerField,
**kwargs,
})
class BigIntegerField(IntegerField):
empty_strings_allowed = False
description = _("Big (8 byte) integer")
MAX_BIGINT = 9223372036854775807
def get_internal_type(self):
return "BigIntegerField"
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': -BigIntegerField.MAX_BIGINT - 1,
'max_value': BigIntegerField.MAX_BIGINT,
**kwargs,
})
class IPAddressField(Field):
empty_strings_allowed = False
description = _("IPv4 address")
system_check_removed_details = {
'msg': (
'IPAddressField has been removed except for support in '
'historical migrations.'
),
'hint': 'Use GenericIPAddressField instead.',
'id': 'fields.E900',
}
def __init__(self, *args, **kwargs):
kwargs['max_length'] = 15
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['max_length']
return name, path, args, kwargs
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
return str(value)
def get_internal_type(self):
return "IPAddressField"
class GenericIPAddressField(Field):
empty_strings_allowed = False
description = _("IP address")
default_error_messages = {}
def __init__(self, verbose_name=None, name=None, protocol='both',
unpack_ipv4=False, *args, **kwargs):
self.unpack_ipv4 = unpack_ipv4
self.protocol = protocol
self.default_validators, invalid_error_message = \
validators.ip_address_validators(protocol, unpack_ipv4)
self.default_error_messages['invalid'] = invalid_error_message
kwargs['max_length'] = 39
super().__init__(verbose_name, name, *args, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_blank_and_null_values(**kwargs),
]
def _check_blank_and_null_values(self, **kwargs):
if not getattr(self, 'null', False) and getattr(self, 'blank', False):
return [
checks.Error(
'GenericIPAddressFields cannot have blank=True if null=False, '
'as blank values are stored as nulls.',
obj=self,
id='fields.E150',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.unpack_ipv4 is not False:
kwargs['unpack_ipv4'] = self.unpack_ipv4
if self.protocol != "both":
kwargs['protocol'] = self.protocol
if kwargs.get("max_length") == 39:
del kwargs['max_length']
return name, path, args, kwargs
def get_internal_type(self):
return "GenericIPAddressField"
def to_python(self, value):
if value is None:
return None
if not isinstance(value, str):
value = str(value)
value = value.strip()
if ':' in value:
return clean_ipv6_address(value, self.unpack_ipv4, self.error_messages['invalid'])
return value
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_ipaddressfield_value(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
if value is None:
return None
if value and ':' in value:
try:
return clean_ipv6_address(value, self.unpack_ipv4)
except exceptions.ValidationError:
pass
return str(value)
def formfield(self, **kwargs):
return super().formfield(**{
'protocol': self.protocol,
'form_class': forms.GenericIPAddressField,
**kwargs,
})
class NullBooleanField(BooleanField):
default_error_messages = {
'invalid': _("'%(value)s' value must be either None, True or False."),
'invalid_nullable': _("'%(value)s' value must be either None, True or False."),
}
description = _("Boolean (Either True, False or None)")
def __init__(self, *args, **kwargs):
kwargs['null'] = True
kwargs['blank'] = True
super().__init__(*args, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['null']
del kwargs['blank']
return name, path, args, kwargs
def get_internal_type(self):
return "NullBooleanField"
class PositiveIntegerRelDbTypeMixin:
def rel_db_type(self, connection):
"""
Return the data type that a related field pointing to this field should
use. In most cases, a foreign key pointing to a positive integer
primary key will have an integer column data type but some databases
(e.g. MySQL) have an unsigned integer type. In that case
(related_fields_match_type=True), the primary key should return its
db_type.
"""
if connection.features.related_fields_match_type:
return self.db_type(connection)
else:
return IntegerField().db_type(connection=connection)
class PositiveIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField):
description = _("Positive integer")
def get_internal_type(self):
return "PositiveIntegerField"
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': 0,
**kwargs,
})
class PositiveSmallIntegerField(PositiveIntegerRelDbTypeMixin, IntegerField):
description = _("Positive small integer")
def get_internal_type(self):
return "PositiveSmallIntegerField"
def formfield(self, **kwargs):
return super().formfield(**{
'min_value': 0,
**kwargs,
})
class SlugField(CharField):
default_validators = [validators.validate_slug]
description = _("Slug (up to %(max_length)s)")
def __init__(self, *args, max_length=50, db_index=True, allow_unicode=False, **kwargs):
self.allow_unicode = allow_unicode
if self.allow_unicode:
self.default_validators = [validators.validate_unicode_slug]
super().__init__(*args, max_length=max_length, db_index=db_index, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 50:
del kwargs['max_length']
if self.db_index is False:
kwargs['db_index'] = False
else:
del kwargs['db_index']
if self.allow_unicode is not False:
kwargs['allow_unicode'] = self.allow_unicode
return name, path, args, kwargs
def get_internal_type(self):
return "SlugField"
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.SlugField,
'allow_unicode': self.allow_unicode,
**kwargs,
})
class SmallIntegerField(IntegerField):
description = _("Small integer")
def get_internal_type(self):
return "SmallIntegerField"
class TextField(Field):
description = _("Text")
def get_internal_type(self):
return "TextField"
def to_python(self, value):
if isinstance(value, str) or value is None:
return value
return str(value)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def formfield(self, **kwargs):
# Passing max_length to forms.CharField means that the value's length
# will be validated twice. This is considered acceptable since we want
# the value in the form field (to pass into widget for example).
return super().formfield(**{
'max_length': self.max_length,
**({} if self.choices else {'widget': forms.Textarea}),
**kwargs,
})
class TimeField(DateTimeCheckMixin, Field):
empty_strings_allowed = False
default_error_messages = {
'invalid': _("'%(value)s' value has an invalid format. It must be in "
"HH:MM[:ss[.uuuuuu]] format."),
'invalid_time': _("'%(value)s' value has the correct format "
"(HH:MM[:ss[.uuuuuu]]) but it is an invalid time."),
}
description = _("Time")
def __init__(self, verbose_name=None, name=None, auto_now=False,
auto_now_add=False, **kwargs):
self.auto_now, self.auto_now_add = auto_now, auto_now_add
if auto_now or auto_now_add:
kwargs['editable'] = False
kwargs['blank'] = True
super().__init__(verbose_name, name, **kwargs)
def _check_fix_default_value(self):
"""
Warn that using an actual date or datetime value is probably wrong;
it's only evaluated on server startup.
"""
if not self.has_default():
return []
now = timezone.now()
if not timezone.is_naive(now):
now = timezone.make_naive(now, timezone.utc)
value = self.default
if isinstance(value, datetime.datetime):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
upper = now + second_offset
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc)
elif isinstance(value, datetime.time):
second_offset = datetime.timedelta(seconds=10)
lower = now - second_offset
upper = now + second_offset
value = datetime.datetime.combine(now.date(), value)
if timezone.is_aware(value):
value = timezone.make_naive(value, timezone.utc).time()
else:
# No explicit time / datetime value -- no checks necessary
return []
if lower <= value <= upper:
return [
checks.Warning(
'Fixed default value provided.',
hint='It seems you set a fixed date / time / datetime '
'value as default for this field. This may not be '
'what you want. If you want to have the current date '
'as default, use `django.utils.timezone.now`',
obj=self,
id='fields.W161',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.auto_now is not False:
kwargs["auto_now"] = self.auto_now
if self.auto_now_add is not False:
kwargs["auto_now_add"] = self.auto_now_add
if self.auto_now or self.auto_now_add:
del kwargs['blank']
del kwargs['editable']
return name, path, args, kwargs
def get_internal_type(self):
return "TimeField"
def to_python(self, value):
if value is None:
return None
if isinstance(value, datetime.time):
return value
if isinstance(value, datetime.datetime):
# Not usually a good idea to pass in a datetime here (it loses
# information), but this can be a side-effect of interacting with a
# database backend (e.g. Oracle), so we'll be accommodating.
return value.time()
try:
parsed = parse_time(value)
if parsed is not None:
return parsed
except ValueError:
raise exceptions.ValidationError(
self.error_messages['invalid_time'],
code='invalid_time',
params={'value': value},
)
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
def pre_save(self, model_instance, add):
if self.auto_now or (self.auto_now_add and add):
value = datetime.datetime.now().time()
setattr(model_instance, self.attname, value)
return value
else:
return super().pre_save(model_instance, add)
def get_prep_value(self, value):
value = super().get_prep_value(value)
return self.to_python(value)
def get_db_prep_value(self, value, connection, prepared=False):
# Casts times into the format expected by the backend
if not prepared:
value = self.get_prep_value(value)
return connection.ops.adapt_timefield_value(value)
def value_to_string(self, obj):
val = self.value_from_object(obj)
return '' if val is None else val.isoformat()
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.TimeField,
**kwargs,
})
class URLField(CharField):
default_validators = [validators.URLValidator()]
description = _("URL")
def __init__(self, verbose_name=None, name=None, **kwargs):
kwargs.setdefault('max_length', 200)
super().__init__(verbose_name, name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 200:
del kwargs['max_length']
return name, path, args, kwargs
def formfield(self, **kwargs):
# As with CharField, this will cause URL validation to be performed
# twice.
return super().formfield(**{
'form_class': forms.URLField,
**kwargs,
})
class BinaryField(Field):
description = _("Raw binary data")
empty_values = [None, b'']
def __init__(self, *args, **kwargs):
kwargs.setdefault('editable', False)
super().__init__(*args, **kwargs)
if self.max_length is not None:
self.validators.append(validators.MaxLengthValidator(self.max_length))
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.editable:
kwargs['editable'] = True
else:
del kwargs['editable']
return name, path, args, kwargs
def get_internal_type(self):
return "BinaryField"
def get_placeholder(self, value, compiler, connection):
return connection.ops.binary_placeholder_sql(value)
def get_default(self):
if self.has_default() and not callable(self.default):
return self.default
default = super().get_default()
if default == '':
return b''
return default
def get_db_prep_value(self, value, connection, prepared=False):
value = super().get_db_prep_value(value, connection, prepared)
if value is not None:
return connection.Database.Binary(value)
return value
def value_to_string(self, obj):
"""Binary data is serialized as base64"""
return b64encode(force_bytes(self.value_from_object(obj))).decode('ascii')
def to_python(self, value):
# If it's a string, it should be base64-encoded data
if isinstance(value, str):
return memoryview(b64decode(force_bytes(value)))
return value
class UUIDField(Field):
default_error_messages = {
'invalid': _("'%(value)s' is not a valid UUID."),
}
description = 'Universally unique identifier'
empty_strings_allowed = False
def __init__(self, verbose_name=None, **kwargs):
kwargs['max_length'] = 32
super().__init__(verbose_name, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['max_length']
return name, path, args, kwargs
def get_internal_type(self):
return "UUIDField"
def get_db_prep_value(self, value, connection, prepared=False):
if value is None:
return None
if not isinstance(value, uuid.UUID):
value = self.to_python(value)
if connection.features.has_native_uuid_field:
return value
return value.hex
def to_python(self, value):
if value is not None and not isinstance(value, uuid.UUID):
try:
return uuid.UUID(value)
except (AttributeError, ValueError):
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
return value
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.UUIDField,
**kwargs,
})
|
dc2cd68f50682ff95a02b8ec0ef56c8ecad9c385c8dae8469a4e7c5b7b2647a1 | import functools
import inspect
from functools import partial
from django import forms
from django.apps import apps
from django.core import checks, exceptions
from django.db import connection, router
from django.db.backends import utils
from django.db.models import Q
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import CASCADE, SET_DEFAULT, SET_NULL
from django.db.models.query_utils import PathInfo
from django.db.models.utils import make_model_tuple
from django.utils.functional import cached_property
from django.utils.translation import gettext_lazy as _
from . import Field
from .mixins import FieldCacheMixin
from .related_descriptors import (
ForwardManyToOneDescriptor, ForwardOneToOneDescriptor,
ManyToManyDescriptor, ReverseManyToOneDescriptor,
ReverseOneToOneDescriptor,
)
from .related_lookups import (
RelatedExact, RelatedGreaterThan, RelatedGreaterThanOrEqual, RelatedIn,
RelatedIsNull, RelatedLessThan, RelatedLessThanOrEqual,
)
from .reverse_related import (
ForeignObjectRel, ManyToManyRel, ManyToOneRel, OneToOneRel,
)
RECURSIVE_RELATIONSHIP_CONSTANT = 'self'
def resolve_relation(scope_model, relation):
"""
Transform relation into a model or fully-qualified model string of the form
"app_label.ModelName", relative to scope_model.
The relation argument can be:
* RECURSIVE_RELATIONSHIP_CONSTANT, i.e. the string "self", in which case
the model argument will be returned.
* A bare model name without an app_label, in which case scope_model's
app_label will be prepended.
* An "app_label.ModelName" string.
* A model class, which will be returned unchanged.
"""
# Check for recursive relations
if relation == RECURSIVE_RELATIONSHIP_CONSTANT:
relation = scope_model
# Look for an "app.Model" relation
if isinstance(relation, str):
if "." not in relation:
relation = "%s.%s" % (scope_model._meta.app_label, relation)
return relation
def lazy_related_operation(function, model, *related_models, **kwargs):
"""
Schedule `function` to be called once `model` and all `related_models`
have been imported and registered with the app registry. `function` will
be called with the newly-loaded model classes as its positional arguments,
plus any optional keyword arguments.
The `model` argument must be a model class. Each subsequent positional
argument is another model, or a reference to another model - see
`resolve_relation()` for the various forms these may take. Any relative
references will be resolved relative to `model`.
This is a convenience wrapper for `Apps.lazy_model_operation` - the app
registry model used is the one found in `model._meta.apps`.
"""
models = [model] + [resolve_relation(model, rel) for rel in related_models]
model_keys = (make_model_tuple(m) for m in models)
apps = model._meta.apps
return apps.lazy_model_operation(partial(function, **kwargs), *model_keys)
class RelatedField(FieldCacheMixin, Field):
"""Base class that all relational fields inherit from."""
# Field flags
one_to_many = False
one_to_one = False
many_to_many = False
many_to_one = False
@cached_property
def related_model(self):
# Can't cache this property until all the models are loaded.
apps.check_models_ready()
return self.remote_field.model
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_related_name_is_valid(),
*self._check_related_query_name_is_valid(),
*self._check_relation_model_exists(),
*self._check_referencing_to_swapped_model(),
*self._check_clashes(),
]
def _check_related_name_is_valid(self):
import keyword
related_name = self.remote_field.related_name
if related_name is None:
return []
is_valid_id = not keyword.iskeyword(related_name) and related_name.isidentifier()
if not (is_valid_id or related_name.endswith('+')):
return [
checks.Error(
"The name '%s' is invalid related_name for field %s.%s" %
(self.remote_field.related_name, self.model._meta.object_name,
self.name),
hint="Related name must be a valid Python identifier or end with a '+'",
obj=self,
id='fields.E306',
)
]
return []
def _check_related_query_name_is_valid(self):
if self.remote_field.is_hidden():
return []
rel_query_name = self.related_query_name()
errors = []
if rel_query_name.endswith('_'):
errors.append(
checks.Error(
"Reverse query name '%s' must not end with an underscore."
% (rel_query_name,),
hint=("Add or change a related_name or related_query_name "
"argument for this field."),
obj=self,
id='fields.E308',
)
)
if LOOKUP_SEP in rel_query_name:
errors.append(
checks.Error(
"Reverse query name '%s' must not contain '%s'."
% (rel_query_name, LOOKUP_SEP),
hint=("Add or change a related_name or related_query_name "
"argument for this field."),
obj=self,
id='fields.E309',
)
)
return errors
def _check_relation_model_exists(self):
rel_is_missing = self.remote_field.model not in self.opts.apps.get_models()
rel_is_string = isinstance(self.remote_field.model, str)
model_name = self.remote_field.model if rel_is_string else self.remote_field.model._meta.object_name
if rel_is_missing and (rel_is_string or not self.remote_field.model._meta.swapped):
return [
checks.Error(
"Field defines a relation with model '%s', which is either "
"not installed, or is abstract." % model_name,
obj=self,
id='fields.E300',
)
]
return []
def _check_referencing_to_swapped_model(self):
if (self.remote_field.model not in self.opts.apps.get_models() and
not isinstance(self.remote_field.model, str) and
self.remote_field.model._meta.swapped):
model = "%s.%s" % (
self.remote_field.model._meta.app_label,
self.remote_field.model._meta.object_name
)
return [
checks.Error(
"Field defines a relation with the model '%s', which has "
"been swapped out." % model,
hint="Update the relation to point at 'settings.%s'." % self.remote_field.model._meta.swappable,
obj=self,
id='fields.E301',
)
]
return []
def _check_clashes(self):
"""Check accessor and reverse query name clashes."""
from django.db.models.base import ModelBase
errors = []
opts = self.model._meta
# `f.remote_field.model` may be a string instead of a model. Skip if model name is
# not resolved.
if not isinstance(self.remote_field.model, ModelBase):
return []
# Consider that we are checking field `Model.foreign` and the models
# are:
#
# class Target(models.Model):
# model = models.IntegerField()
# model_set = models.IntegerField()
#
# class Model(models.Model):
# foreign = models.ForeignKey(Target)
# m2m = models.ManyToManyField(Target)
# rel_opts.object_name == "Target"
rel_opts = self.remote_field.model._meta
# If the field doesn't install a backward relation on the target model
# (so `is_hidden` returns True), then there are no clashes to check
# and we can skip these fields.
rel_is_hidden = self.remote_field.is_hidden()
rel_name = self.remote_field.get_accessor_name() # i. e. "model_set"
rel_query_name = self.related_query_name() # i. e. "model"
field_name = "%s.%s" % (opts.object_name, self.name) # i. e. "Model.field"
# Check clashes between accessor or reverse query name of `field`
# and any other field name -- i.e. accessor for Model.foreign is
# model_set and it clashes with Target.model_set.
potential_clashes = rel_opts.fields + rel_opts.many_to_many
for clash_field in potential_clashes:
clash_name = "%s.%s" % (rel_opts.object_name, clash_field.name) # i.e. "Target.model_set"
if not rel_is_hidden and clash_field.name == rel_name:
errors.append(
checks.Error(
"Reverse accessor for '%s' clashes with field name '%s'." % (field_name, clash_name),
hint=("Rename field '%s', or add/change a related_name "
"argument to the definition for field '%s'.") % (clash_name, field_name),
obj=self,
id='fields.E302',
)
)
if clash_field.name == rel_query_name:
errors.append(
checks.Error(
"Reverse query name for '%s' clashes with field name '%s'." % (field_name, clash_name),
hint=("Rename field '%s', or add/change a related_name "
"argument to the definition for field '%s'.") % (clash_name, field_name),
obj=self,
id='fields.E303',
)
)
# Check clashes between accessors/reverse query names of `field` and
# any other field accessor -- i. e. Model.foreign accessor clashes with
# Model.m2m accessor.
potential_clashes = (r for r in rel_opts.related_objects if r.field is not self)
for clash_field in potential_clashes:
clash_name = "%s.%s" % ( # i. e. "Model.m2m"
clash_field.related_model._meta.object_name,
clash_field.field.name)
if not rel_is_hidden and clash_field.get_accessor_name() == rel_name:
errors.append(
checks.Error(
"Reverse accessor for '%s' clashes with reverse accessor for '%s'." % (field_name, clash_name),
hint=("Add or change a related_name argument "
"to the definition for '%s' or '%s'.") % (field_name, clash_name),
obj=self,
id='fields.E304',
)
)
if clash_field.get_accessor_name() == rel_query_name:
errors.append(
checks.Error(
"Reverse query name for '%s' clashes with reverse query name for '%s'."
% (field_name, clash_name),
hint=("Add or change a related_name argument "
"to the definition for '%s' or '%s'.") % (field_name, clash_name),
obj=self,
id='fields.E305',
)
)
return errors
def db_type(self, connection):
# By default related field will not have a column as it relates to
# columns from another table.
return None
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super().contribute_to_class(cls, name, private_only=private_only, **kwargs)
self.opts = cls._meta
if not cls._meta.abstract:
if self.remote_field.related_name:
related_name = self.remote_field.related_name
else:
related_name = self.opts.default_related_name
if related_name:
related_name = related_name % {
'class': cls.__name__.lower(),
'model_name': cls._meta.model_name.lower(),
'app_label': cls._meta.app_label.lower()
}
self.remote_field.related_name = related_name
if self.remote_field.related_query_name:
related_query_name = self.remote_field.related_query_name % {
'class': cls.__name__.lower(),
'app_label': cls._meta.app_label.lower(),
}
self.remote_field.related_query_name = related_query_name
def resolve_related_class(model, related, field):
field.remote_field.model = related
field.do_related_class(related, model)
lazy_related_operation(resolve_related_class, cls, self.remote_field.model, field=self)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.remote_field.limit_choices_to:
kwargs['limit_choices_to'] = self.remote_field.limit_choices_to
if self.remote_field.related_name is not None:
kwargs['related_name'] = self.remote_field.related_name
if self.remote_field.related_query_name is not None:
kwargs['related_query_name'] = self.remote_field.related_query_name
return name, path, args, kwargs
def get_forward_related_filter(self, obj):
"""
Return the keyword arguments that when supplied to
self.model.object.filter(), would select all instances related through
this field to the remote obj. This is used to build the querysets
returned by related descriptors. obj is an instance of
self.related_field.model.
"""
return {
'%s__%s' % (self.name, rh_field.name): getattr(obj, rh_field.attname)
for _, rh_field in self.related_fields
}
def get_reverse_related_filter(self, obj):
"""
Complement to get_forward_related_filter(). Return the keyword
arguments that when passed to self.related_field.model.object.filter()
select all instances of self.related_field.model related through
this field to obj. obj is an instance of self.model.
"""
base_filter = {
rh_field.attname: getattr(obj, lh_field.attname)
for lh_field, rh_field in self.related_fields
}
descriptor_filter = self.get_extra_descriptor_filter(obj)
base_q = Q(**base_filter)
if isinstance(descriptor_filter, dict):
return base_q & Q(**descriptor_filter)
elif descriptor_filter:
return base_q & descriptor_filter
return base_q
@property
def swappable_setting(self):
"""
Get the setting that this is powered from for swapping, or None
if it's not swapped in / marked with swappable=False.
"""
if self.swappable:
# Work out string form of "to"
if isinstance(self.remote_field.model, str):
to_string = self.remote_field.model
else:
to_string = self.remote_field.model._meta.label
return apps.get_swappable_settings_name(to_string)
return None
def set_attributes_from_rel(self):
self.name = (
self.name or
(self.remote_field.model._meta.model_name + '_' + self.remote_field.model._meta.pk.name)
)
if self.verbose_name is None:
self.verbose_name = self.remote_field.model._meta.verbose_name
self.remote_field.set_field_name()
def do_related_class(self, other, cls):
self.set_attributes_from_rel()
self.contribute_to_related_class(other, self.remote_field)
def get_limit_choices_to(self):
"""
Return ``limit_choices_to`` for this model field.
If it is a callable, it will be invoked and the result will be
returned.
"""
if callable(self.remote_field.limit_choices_to):
return self.remote_field.limit_choices_to()
return self.remote_field.limit_choices_to
def formfield(self, **kwargs):
"""
Pass ``limit_choices_to`` to the field being constructed.
Only passes it if there is a type that supports related fields.
This is a similar strategy used to pass the ``queryset`` to the field
being constructed.
"""
defaults = {}
if hasattr(self.remote_field, 'get_related_field'):
# If this is a callable, do not invoke it here. Just pass
# it in the defaults for when the form class will later be
# instantiated.
limit_choices_to = self.remote_field.limit_choices_to
defaults.update({
'limit_choices_to': limit_choices_to,
})
defaults.update(kwargs)
return super().formfield(**defaults)
def related_query_name(self):
"""
Define the name that can be used to identify this related object in a
table-spanning query.
"""
return self.remote_field.related_query_name or self.remote_field.related_name or self.opts.model_name
@property
def target_field(self):
"""
When filtering against this relation, return the field on the remote
model against which the filtering should happen.
"""
target_fields = self.get_path_info()[-1].target_fields
if len(target_fields) > 1:
raise exceptions.FieldError(
"The relation has multiple target fields, but only single target field was asked for")
return target_fields[0]
def get_cache_name(self):
return self.name
class ForeignObject(RelatedField):
"""
Abstraction of the ForeignKey relation to support multi-column relations.
"""
# Field flags
many_to_many = False
many_to_one = True
one_to_many = False
one_to_one = False
requires_unique_target = True
related_accessor_class = ReverseManyToOneDescriptor
forward_related_accessor_class = ForwardManyToOneDescriptor
rel_class = ForeignObjectRel
def __init__(self, to, on_delete, from_fields, to_fields, rel=None, related_name=None,
related_query_name=None, limit_choices_to=None, parent_link=False,
swappable=True, **kwargs):
if rel is None:
rel = self.rel_class(
self, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
super().__init__(rel=rel, **kwargs)
self.from_fields = from_fields
self.to_fields = to_fields
self.swappable = swappable
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_to_fields_exist(),
*self._check_unique_target(),
]
def _check_to_fields_exist(self):
# Skip nonexistent models.
if isinstance(self.remote_field.model, str):
return []
errors = []
for to_field in self.to_fields:
if to_field:
try:
self.remote_field.model._meta.get_field(to_field)
except exceptions.FieldDoesNotExist:
errors.append(
checks.Error(
"The to_field '%s' doesn't exist on the related "
"model '%s'."
% (to_field, self.remote_field.model._meta.label),
obj=self,
id='fields.E312',
)
)
return errors
def _check_unique_target(self):
rel_is_string = isinstance(self.remote_field.model, str)
if rel_is_string or not self.requires_unique_target:
return []
try:
self.foreign_related_fields
except exceptions.FieldDoesNotExist:
return []
if not self.foreign_related_fields:
return []
unique_foreign_fields = {
frozenset([f.name])
for f in self.remote_field.model._meta.get_fields()
if getattr(f, 'unique', False)
}
unique_foreign_fields.update({
frozenset(ut)
for ut in self.remote_field.model._meta.unique_together
})
foreign_fields = {f.name for f in self.foreign_related_fields}
has_unique_constraint = any(u <= foreign_fields for u in unique_foreign_fields)
if not has_unique_constraint and len(self.foreign_related_fields) > 1:
field_combination = ', '.join(
"'%s'" % rel_field.name for rel_field in self.foreign_related_fields
)
model_name = self.remote_field.model.__name__
return [
checks.Error(
"No subset of the fields %s on model '%s' is unique."
% (field_combination, model_name),
hint=(
"Add unique=True on any of those fields or add at "
"least a subset of them to a unique_together constraint."
),
obj=self,
id='fields.E310',
)
]
elif not has_unique_constraint:
field_name = self.foreign_related_fields[0].name
model_name = self.remote_field.model.__name__
return [
checks.Error(
"'%s.%s' must set unique=True because it is referenced by "
"a foreign key." % (model_name, field_name),
obj=self,
id='fields.E311',
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
kwargs['on_delete'] = self.remote_field.on_delete
kwargs['from_fields'] = self.from_fields
kwargs['to_fields'] = self.to_fields
if self.remote_field.parent_link:
kwargs['parent_link'] = self.remote_field.parent_link
# Work out string form of "to"
if isinstance(self.remote_field.model, str):
kwargs['to'] = self.remote_field.model
else:
kwargs['to'] = "%s.%s" % (
self.remote_field.model._meta.app_label,
self.remote_field.model._meta.object_name,
)
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error
if hasattr(kwargs['to'], "setting_name"):
if kwargs['to'].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ForeignKey pointing to a model "
"that is swapped in place of more than one model (%s and %s)"
% (kwargs['to'].setting_name, swappable_setting)
)
# Set it
from django.db.migrations.writer import SettingsReference
kwargs['to'] = SettingsReference(
kwargs['to'],
swappable_setting,
)
return name, path, args, kwargs
def resolve_related_fields(self):
if not self.from_fields or len(self.from_fields) != len(self.to_fields):
raise ValueError('Foreign Object from and to fields must be the same non-zero length')
if isinstance(self.remote_field.model, str):
raise ValueError('Related model %r cannot be resolved' % self.remote_field.model)
related_fields = []
for index in range(len(self.from_fields)):
from_field_name = self.from_fields[index]
to_field_name = self.to_fields[index]
from_field = (self if from_field_name == 'self'
else self.opts.get_field(from_field_name))
to_field = (self.remote_field.model._meta.pk if to_field_name is None
else self.remote_field.model._meta.get_field(to_field_name))
related_fields.append((from_field, to_field))
return related_fields
@property
def related_fields(self):
if not hasattr(self, '_related_fields'):
self._related_fields = self.resolve_related_fields()
return self._related_fields
@property
def reverse_related_fields(self):
return [(rhs_field, lhs_field) for lhs_field, rhs_field in self.related_fields]
@property
def local_related_fields(self):
return tuple(lhs_field for lhs_field, rhs_field in self.related_fields)
@property
def foreign_related_fields(self):
return tuple(rhs_field for lhs_field, rhs_field in self.related_fields if rhs_field)
def get_local_related_value(self, instance):
return self.get_instance_value_for_fields(instance, self.local_related_fields)
def get_foreign_related_value(self, instance):
return self.get_instance_value_for_fields(instance, self.foreign_related_fields)
@staticmethod
def get_instance_value_for_fields(instance, fields):
ret = []
opts = instance._meta
for field in fields:
# Gotcha: in some cases (like fixture loading) a model can have
# different values in parent_ptr_id and parent's id. So, use
# instance.pk (that is, parent_ptr_id) when asked for instance.id.
if field.primary_key:
possible_parent_link = opts.get_ancestor_link(field.model)
if (not possible_parent_link or
possible_parent_link.primary_key or
possible_parent_link.model._meta.abstract):
ret.append(instance.pk)
continue
ret.append(getattr(instance, field.attname))
return tuple(ret)
def get_attname_column(self):
attname, column = super().get_attname_column()
return attname, None
def get_joining_columns(self, reverse_join=False):
source = self.reverse_related_fields if reverse_join else self.related_fields
return tuple((lhs_field.column, rhs_field.column) for lhs_field, rhs_field in source)
def get_reverse_joining_columns(self):
return self.get_joining_columns(reverse_join=True)
def get_extra_descriptor_filter(self, instance):
"""
Return an extra filter condition for related object fetching when
user does 'instance.fieldname', that is the extra filter is used in
the descriptor of the field.
The filter should be either a dict usable in .filter(**kwargs) call or
a Q-object. The condition will be ANDed together with the relation's
joining columns.
A parallel method is get_extra_restriction() which is used in
JOIN and subquery conditions.
"""
return {}
def get_extra_restriction(self, where_class, alias, related_alias):
"""
Return a pair condition used for joining and subquery pushdown. The
condition is something that responds to as_sql(compiler, connection)
method.
Note that currently referring both the 'alias' and 'related_alias'
will not work in some conditions, like subquery pushdown.
A parallel method is get_extra_descriptor_filter() which is used in
instance.fieldname related object fetching.
"""
return None
def get_path_info(self, filtered_relation=None):
"""Get path from this field to the related model."""
opts = self.remote_field.model._meta
from_opts = self.model._meta
return [PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=self.foreign_related_fields,
join_field=self,
m2m=False,
direct=True,
filtered_relation=filtered_relation,
)]
def get_reverse_path_info(self, filtered_relation=None):
"""Get path from the related model to this field's model."""
opts = self.model._meta
from_opts = self.remote_field.model._meta
return [PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=(opts.pk,),
join_field=self.remote_field,
m2m=not self.unique,
direct=False,
filtered_relation=filtered_relation,
)]
@classmethod
@functools.lru_cache(maxsize=None)
def get_lookups(cls):
bases = inspect.getmro(cls)
bases = bases[:bases.index(ForeignObject) + 1]
class_lookups = [parent.__dict__.get('class_lookups', {}) for parent in bases]
return cls.merge_dicts(class_lookups)
def contribute_to_class(self, cls, name, private_only=False, **kwargs):
super().contribute_to_class(cls, name, private_only=private_only, **kwargs)
setattr(cls, self.name, self.forward_related_accessor_class(self))
def contribute_to_related_class(self, cls, related):
# Internal FK's - i.e., those with a related name ending with '+' -
# and swapped models don't get a related descriptor.
if not self.remote_field.is_hidden() and not related.related_model._meta.swapped:
setattr(cls._meta.concrete_model, related.get_accessor_name(), self.related_accessor_class(related))
# While 'limit_choices_to' might be a callable, simply pass
# it along for later - this is too early because it's still
# model load time.
if self.remote_field.limit_choices_to:
cls._meta.related_fkey_lookups.append(self.remote_field.limit_choices_to)
ForeignObject.register_lookup(RelatedIn)
ForeignObject.register_lookup(RelatedExact)
ForeignObject.register_lookup(RelatedLessThan)
ForeignObject.register_lookup(RelatedGreaterThan)
ForeignObject.register_lookup(RelatedGreaterThanOrEqual)
ForeignObject.register_lookup(RelatedLessThanOrEqual)
ForeignObject.register_lookup(RelatedIsNull)
class ForeignKey(ForeignObject):
"""
Provide a many-to-one relation by adding a column to the local model
to hold the remote value.
By default ForeignKey will target the pk of the remote model but this
behavior can be changed by using the ``to_field`` argument.
"""
# Field flags
many_to_many = False
many_to_one = True
one_to_many = False
one_to_one = False
rel_class = ManyToOneRel
empty_strings_allowed = False
default_error_messages = {
'invalid': _('%(model)s instance with %(field)s %(value)r does not exist.')
}
description = _("Foreign Key (type determined by related field)")
def __init__(self, to, on_delete, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, to_field=None,
db_constraint=True, **kwargs):
try:
to._meta.model_name
except AttributeError:
assert isinstance(to, str), (
"%s(%r) is invalid. First parameter to ForeignKey must be "
"either a model, a model name, or the string %r" % (
self.__class__.__name__, to,
RECURSIVE_RELATIONSHIP_CONSTANT,
)
)
else:
# For backwards compatibility purposes, we need to *try* and set
# the to_field during FK construction. It won't be guaranteed to
# be correct until contribute_to_class is called. Refs #12190.
to_field = to_field or (to._meta.pk and to._meta.pk.name)
kwargs['rel'] = self.rel_class(
self, to, to_field,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
kwargs.setdefault('db_index', True)
super().__init__(to, on_delete, from_fields=['self'], to_fields=[to_field], **kwargs)
self.db_constraint = db_constraint
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_on_delete(),
*self._check_unique(),
]
def _check_on_delete(self):
on_delete = getattr(self.remote_field, 'on_delete', None)
if on_delete == SET_NULL and not self.null:
return [
checks.Error(
'Field specifies on_delete=SET_NULL, but cannot be null.',
hint='Set null=True argument on the field, or change the on_delete rule.',
obj=self,
id='fields.E320',
)
]
elif on_delete == SET_DEFAULT and not self.has_default():
return [
checks.Error(
'Field specifies on_delete=SET_DEFAULT, but has no default value.',
hint='Set a default value, or change the on_delete rule.',
obj=self,
id='fields.E321',
)
]
else:
return []
def _check_unique(self, **kwargs):
return [
checks.Warning(
'Setting unique=True on a ForeignKey has the same effect as using a OneToOneField.',
hint='ForeignKey(unique=True) is usually better served by a OneToOneField.',
obj=self,
id='fields.W342',
)
] if self.unique else []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
del kwargs['to_fields']
del kwargs['from_fields']
# Handle the simpler arguments
if self.db_index:
del kwargs['db_index']
else:
kwargs['db_index'] = False
if self.db_constraint is not True:
kwargs['db_constraint'] = self.db_constraint
# Rel needs more work.
to_meta = getattr(self.remote_field.model, "_meta", None)
if self.remote_field.field_name and (
not to_meta or (to_meta.pk and self.remote_field.field_name != to_meta.pk.name)):
kwargs['to_field'] = self.remote_field.field_name
return name, path, args, kwargs
def to_python(self, value):
return self.target_field.to_python(value)
@property
def target_field(self):
return self.foreign_related_fields[0]
def get_reverse_path_info(self, filtered_relation=None):
"""Get path from the related model to this field's model."""
opts = self.model._meta
from_opts = self.remote_field.model._meta
return [PathInfo(
from_opts=from_opts,
to_opts=opts,
target_fields=(opts.pk,),
join_field=self.remote_field,
m2m=not self.unique,
direct=False,
filtered_relation=filtered_relation,
)]
def validate(self, value, model_instance):
if self.remote_field.parent_link:
return
super().validate(value, model_instance)
if value is None:
return
using = router.db_for_read(self.remote_field.model, instance=model_instance)
qs = self.remote_field.model._default_manager.using(using).filter(
**{self.remote_field.field_name: value}
)
qs = qs.complex_filter(self.get_limit_choices_to())
if not qs.exists():
raise exceptions.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={
'model': self.remote_field.model._meta.verbose_name, 'pk': value,
'field': self.remote_field.field_name, 'value': value,
}, # 'pk' is included for backwards compatibility
)
def get_attname(self):
return '%s_id' % self.name
def get_attname_column(self):
attname = self.get_attname()
column = self.db_column or attname
return attname, column
def get_default(self):
"""Return the to_field if the default value is an object."""
field_default = super().get_default()
if isinstance(field_default, self.remote_field.model):
return getattr(field_default, self.target_field.attname)
return field_default
def get_db_prep_save(self, value, connection):
if value is None or (value == '' and
(not self.target_field.empty_strings_allowed or
connection.features.interprets_empty_strings_as_nulls)):
return None
else:
return self.target_field.get_db_prep_save(value, connection=connection)
def get_db_prep_value(self, value, connection, prepared=False):
return self.target_field.get_db_prep_value(value, connection, prepared)
def contribute_to_related_class(self, cls, related):
super().contribute_to_related_class(cls, related)
if self.remote_field.field_name is None:
self.remote_field.field_name = cls._meta.pk.name
def formfield(self, *, using=None, **kwargs):
if isinstance(self.remote_field.model, str):
raise ValueError("Cannot create form field for %r yet, because "
"its related model %r has not been loaded yet" %
(self.name, self.remote_field.model))
return super().formfield(**{
'form_class': forms.ModelChoiceField,
'queryset': self.remote_field.model._default_manager.using(using),
'to_field_name': self.remote_field.field_name,
**kwargs,
})
def db_check(self, connection):
return []
def db_type(self, connection):
return self.target_field.rel_db_type(connection=connection)
def db_parameters(self, connection):
return {"type": self.db_type(connection), "check": self.db_check(connection)}
def convert_empty_strings(self, value, expression, connection):
if (not value) and isinstance(value, str):
return None
return value
def get_db_converters(self, connection):
converters = super().get_db_converters(connection)
if connection.features.interprets_empty_strings_as_nulls:
converters += [self.convert_empty_strings]
return converters
def get_col(self, alias, output_field=None):
return super().get_col(alias, output_field or self.target_field)
class OneToOneField(ForeignKey):
"""
A OneToOneField is essentially the same as a ForeignKey, with the exception
that it always carries a "unique" constraint with it and the reverse
relation always returns the object pointed to (since there will only ever
be one), rather than returning a list.
"""
# Field flags
many_to_many = False
many_to_one = False
one_to_many = False
one_to_one = True
related_accessor_class = ReverseOneToOneDescriptor
forward_related_accessor_class = ForwardOneToOneDescriptor
rel_class = OneToOneRel
description = _("One-to-one relationship")
def __init__(self, to, on_delete, to_field=None, **kwargs):
kwargs['unique'] = True
super().__init__(to, on_delete, to_field=to_field, **kwargs)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if "unique" in kwargs:
del kwargs['unique']
return name, path, args, kwargs
def formfield(self, **kwargs):
if self.remote_field.parent_link:
return None
return super().formfield(**kwargs)
def save_form_data(self, instance, data):
if isinstance(data, self.remote_field.model):
setattr(instance, self.name, data)
else:
setattr(instance, self.attname, data)
def _check_unique(self, **kwargs):
# Override ForeignKey since check isn't applicable here.
return []
def create_many_to_many_intermediary_model(field, klass):
from django.db import models
def set_managed(model, related, through):
through._meta.managed = model._meta.managed or related._meta.managed
to_model = resolve_relation(klass, field.remote_field.model)
name = '%s_%s' % (klass._meta.object_name, field.name)
lazy_related_operation(set_managed, klass, to_model, name)
to = make_model_tuple(to_model)[1]
from_ = klass._meta.model_name
if to == from_:
to = 'to_%s' % to
from_ = 'from_%s' % from_
meta = type('Meta', (), {
'db_table': field._get_m2m_db_table(klass._meta),
'auto_created': klass,
'app_label': klass._meta.app_label,
'db_tablespace': klass._meta.db_tablespace,
'unique_together': (from_, to),
'verbose_name': _('%(from)s-%(to)s relationship') % {'from': from_, 'to': to},
'verbose_name_plural': _('%(from)s-%(to)s relationships') % {'from': from_, 'to': to},
'apps': field.model._meta.apps,
})
# Construct and return the new class.
return type(name, (models.Model,), {
'Meta': meta,
'__module__': klass.__module__,
from_: models.ForeignKey(
klass,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
),
to: models.ForeignKey(
to_model,
related_name='%s+' % name,
db_tablespace=field.db_tablespace,
db_constraint=field.remote_field.db_constraint,
on_delete=CASCADE,
)
})
class ManyToManyField(RelatedField):
"""
Provide a many-to-many relation by using an intermediary model that
holds two ForeignKey fields pointed at the two sides of the relation.
Unless a ``through`` model was provided, ManyToManyField will use the
create_many_to_many_intermediary_model factory to automatically generate
the intermediary model.
"""
# Field flags
many_to_many = True
many_to_one = False
one_to_many = False
one_to_one = False
rel_class = ManyToManyRel
description = _("Many-to-many relationship")
def __init__(self, to, related_name=None, related_query_name=None,
limit_choices_to=None, symmetrical=None, through=None,
through_fields=None, db_constraint=True, db_table=None,
swappable=True, **kwargs):
try:
to._meta
except AttributeError:
assert isinstance(to, str), (
"%s(%r) is invalid. First parameter to ManyToManyField must be "
"either a model, a model name, or the string %r" %
(self.__class__.__name__, to, RECURSIVE_RELATIONSHIP_CONSTANT)
)
if symmetrical is None:
symmetrical = (to == RECURSIVE_RELATIONSHIP_CONSTANT)
if through is not None:
assert db_table is None, (
"Cannot specify a db_table if an intermediary model is used."
)
kwargs['rel'] = self.rel_class(
self, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
symmetrical=symmetrical,
through=through,
through_fields=through_fields,
db_constraint=db_constraint,
)
self.has_null_arg = 'null' in kwargs
super().__init__(**kwargs)
self.db_table = db_table
self.swappable = swappable
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_unique(**kwargs),
*self._check_relationship_model(**kwargs),
*self._check_ignored_options(**kwargs),
*self._check_table_uniqueness(**kwargs),
]
def _check_unique(self, **kwargs):
if self.unique:
return [
checks.Error(
'ManyToManyFields cannot be unique.',
obj=self,
id='fields.E330',
)
]
return []
def _check_ignored_options(self, **kwargs):
warnings = []
if self.has_null_arg:
warnings.append(
checks.Warning(
'null has no effect on ManyToManyField.',
obj=self,
id='fields.W340',
)
)
if self._validators:
warnings.append(
checks.Warning(
'ManyToManyField does not support validators.',
obj=self,
id='fields.W341',
)
)
if (self.remote_field.limit_choices_to and self.remote_field.through and
not self.remote_field.through._meta.auto_created):
warnings.append(
checks.Warning(
'limit_choices_to has no effect on ManyToManyField '
'with a through model.',
obj=self,
id='fields.W343',
)
)
return warnings
def _check_relationship_model(self, from_model=None, **kwargs):
if hasattr(self.remote_field.through, '_meta'):
qualified_model_name = "%s.%s" % (
self.remote_field.through._meta.app_label, self.remote_field.through.__name__)
else:
qualified_model_name = self.remote_field.through
errors = []
if self.remote_field.through not in self.opts.apps.get_models(include_auto_created=True):
# The relationship model is not installed.
errors.append(
checks.Error(
"Field specifies a many-to-many relation through model "
"'%s', which has not been installed." % qualified_model_name,
obj=self,
id='fields.E331',
)
)
else:
assert from_model is not None, (
"ManyToManyField with intermediate "
"tables cannot be checked if you don't pass the model "
"where the field is attached to."
)
# Set some useful local variables
to_model = resolve_relation(from_model, self.remote_field.model)
from_model_name = from_model._meta.object_name
if isinstance(to_model, str):
to_model_name = to_model
else:
to_model_name = to_model._meta.object_name
relationship_model_name = self.remote_field.through._meta.object_name
self_referential = from_model == to_model
# Check symmetrical attribute.
if (self_referential and self.remote_field.symmetrical and
not self.remote_field.through._meta.auto_created):
errors.append(
checks.Error(
'Many-to-many fields with intermediate tables must not be symmetrical.',
obj=self,
id='fields.E332',
)
)
# Count foreign keys in intermediate model
if self_referential:
seen_self = sum(
from_model == getattr(field.remote_field, 'model', None)
for field in self.remote_field.through._meta.fields
)
if seen_self > 2 and not self.remote_field.through_fields:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it has more than two foreign keys "
"to '%s', which is ambiguous. You must specify "
"which two foreign keys Django should use via the "
"through_fields keyword argument." % (self, from_model_name),
hint="Use through_fields to specify which two foreign keys Django should use.",
obj=self.remote_field.through,
id='fields.E333',
)
)
else:
# Count foreign keys in relationship model
seen_from = sum(
from_model == getattr(field.remote_field, 'model', None)
for field in self.remote_field.through._meta.fields
)
seen_to = sum(
to_model == getattr(field.remote_field, 'model', None)
for field in self.remote_field.through._meta.fields
)
if seen_from > 1 and not self.remote_field.through_fields:
errors.append(
checks.Error(
("The model is used as an intermediate model by "
"'%s', but it has more than one foreign key "
"from '%s', which is ambiguous. You must specify "
"which foreign key Django should use via the "
"through_fields keyword argument.") % (self, from_model_name),
hint=(
'If you want to create a recursive relationship, '
'use ForeignKey("self", symmetrical=False, through="%s").'
) % relationship_model_name,
obj=self,
id='fields.E334',
)
)
if seen_to > 1 and not self.remote_field.through_fields:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it has more than one foreign key "
"to '%s', which is ambiguous. You must specify "
"which foreign key Django should use via the "
"through_fields keyword argument." % (self, to_model_name),
hint=(
'If you want to create a recursive relationship, '
'use ForeignKey("self", symmetrical=False, through="%s").'
) % relationship_model_name,
obj=self,
id='fields.E335',
)
)
if seen_from == 0 or seen_to == 0:
errors.append(
checks.Error(
"The model is used as an intermediate model by "
"'%s', but it does not have a foreign key to '%s' or '%s'." % (
self, from_model_name, to_model_name
),
obj=self.remote_field.through,
id='fields.E336',
)
)
# Validate `through_fields`.
if self.remote_field.through_fields is not None:
# Validate that we're given an iterable of at least two items
# and that none of them is "falsy".
if not (len(self.remote_field.through_fields) >= 2 and
self.remote_field.through_fields[0] and self.remote_field.through_fields[1]):
errors.append(
checks.Error(
"Field specifies 'through_fields' but does not provide "
"the names of the two link fields that should be used "
"for the relation through model '%s'." % qualified_model_name,
hint="Make sure you specify 'through_fields' as through_fields=('field1', 'field2')",
obj=self,
id='fields.E337',
)
)
# Validate the given through fields -- they should be actual
# fields on the through model, and also be foreign keys to the
# expected models.
else:
assert from_model is not None, (
"ManyToManyField with intermediate "
"tables cannot be checked if you don't pass the model "
"where the field is attached to."
)
source, through, target = from_model, self.remote_field.through, self.remote_field.model
source_field_name, target_field_name = self.remote_field.through_fields[:2]
for field_name, related_model in ((source_field_name, source),
(target_field_name, target)):
possible_field_names = []
for f in through._meta.fields:
if hasattr(f, 'remote_field') and getattr(f.remote_field, 'model', None) == related_model:
possible_field_names.append(f.name)
if possible_field_names:
hint = "Did you mean one of the following foreign keys to '%s': %s?" % (
related_model._meta.object_name,
', '.join(possible_field_names),
)
else:
hint = None
try:
field = through._meta.get_field(field_name)
except exceptions.FieldDoesNotExist:
errors.append(
checks.Error(
"The intermediary model '%s' has no field '%s'."
% (qualified_model_name, field_name),
hint=hint,
obj=self,
id='fields.E338',
)
)
else:
if not (hasattr(field, 'remote_field') and
getattr(field.remote_field, 'model', None) == related_model):
errors.append(
checks.Error(
"'%s.%s' is not a foreign key to '%s'." % (
through._meta.object_name, field_name,
related_model._meta.object_name,
),
hint=hint,
obj=self,
id='fields.E339',
)
)
return errors
def _check_table_uniqueness(self, **kwargs):
if isinstance(self.remote_field.through, str) or not self.remote_field.through._meta.managed:
return []
registered_tables = {
model._meta.db_table: model
for model in self.opts.apps.get_models(include_auto_created=True)
if model != self.remote_field.through and model._meta.managed
}
m2m_db_table = self.m2m_db_table()
model = registered_tables.get(m2m_db_table)
# The second condition allows multiple m2m relations on a model if
# some point to a through model that proxies another through model.
if model and model._meta.concrete_model != self.remote_field.through._meta.concrete_model:
if model._meta.auto_created:
def _get_field_name(model):
for field in model._meta.auto_created._meta.many_to_many:
if field.remote_field.through is model:
return field.name
opts = model._meta.auto_created._meta
clashing_obj = '%s.%s' % (opts.label, _get_field_name(model))
else:
clashing_obj = '%s' % model._meta.label
return [
checks.Error(
"The field's intermediary table '%s' clashes with the "
"table name of '%s'." % (m2m_db_table, clashing_obj),
obj=self,
id='fields.E340',
)
]
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
# Handle the simpler arguments.
if self.db_table is not None:
kwargs['db_table'] = self.db_table
if self.remote_field.db_constraint is not True:
kwargs['db_constraint'] = self.remote_field.db_constraint
# Rel needs more work.
if isinstance(self.remote_field.model, str):
kwargs['to'] = self.remote_field.model
else:
kwargs['to'] = "%s.%s" % (
self.remote_field.model._meta.app_label,
self.remote_field.model._meta.object_name,
)
if getattr(self.remote_field, 'through', None) is not None:
if isinstance(self.remote_field.through, str):
kwargs['through'] = self.remote_field.through
elif not self.remote_field.through._meta.auto_created:
kwargs['through'] = "%s.%s" % (
self.remote_field.through._meta.app_label,
self.remote_field.through._meta.object_name,
)
# If swappable is True, then see if we're actually pointing to the target
# of a swap.
swappable_setting = self.swappable_setting
if swappable_setting is not None:
# If it's already a settings reference, error.
if hasattr(kwargs['to'], "setting_name"):
if kwargs['to'].setting_name != swappable_setting:
raise ValueError(
"Cannot deconstruct a ManyToManyField pointing to a "
"model that is swapped in place of more than one model "
"(%s and %s)" % (kwargs['to'].setting_name, swappable_setting)
)
from django.db.migrations.writer import SettingsReference
kwargs['to'] = SettingsReference(
kwargs['to'],
swappable_setting,
)
return name, path, args, kwargs
def _get_path_info(self, direct=False, filtered_relation=None):
"""Called by both direct and indirect m2m traversal."""
int_model = self.remote_field.through
linkfield1 = int_model._meta.get_field(self.m2m_field_name())
linkfield2 = int_model._meta.get_field(self.m2m_reverse_field_name())
if direct:
join1infos = linkfield1.get_reverse_path_info()
join2infos = linkfield2.get_path_info(filtered_relation)
else:
join1infos = linkfield2.get_reverse_path_info()
join2infos = linkfield1.get_path_info(filtered_relation)
# Get join infos between the last model of join 1 and the first model
# of join 2. Assume the only reason these may differ is due to model
# inheritance.
join1_final = join1infos[-1].to_opts
join2_initial = join2infos[0].from_opts
if join1_final is join2_initial:
intermediate_infos = []
elif issubclass(join1_final.model, join2_initial.model):
intermediate_infos = join1_final.get_path_to_parent(join2_initial.model)
else:
intermediate_infos = join2_initial.get_path_from_parent(join1_final.model)
return [*join1infos, *intermediate_infos, *join2infos]
def get_path_info(self, filtered_relation=None):
return self._get_path_info(direct=True, filtered_relation=filtered_relation)
def get_reverse_path_info(self, filtered_relation=None):
return self._get_path_info(direct=False, filtered_relation=filtered_relation)
def _get_m2m_db_table(self, opts):
"""
Function that can be curried to provide the m2m table name for this
relation.
"""
if self.remote_field.through is not None:
return self.remote_field.through._meta.db_table
elif self.db_table:
return self.db_table
else:
m2m_table_name = '%s_%s' % (utils.strip_quotes(opts.db_table), self.name)
return utils.truncate_name(m2m_table_name, connection.ops.max_name_length())
def _get_m2m_attr(self, related, attr):
"""
Function that can be curried to provide the source accessor or DB
column name for the m2m table.
"""
cache_attr = '_m2m_%s_cache' % attr
if hasattr(self, cache_attr):
return getattr(self, cache_attr)
if self.remote_field.through_fields is not None:
link_field_name = self.remote_field.through_fields[0]
else:
link_field_name = None
for f in self.remote_field.through._meta.fields:
if (f.is_relation and f.remote_field.model == related.related_model and
(link_field_name is None or link_field_name == f.name)):
setattr(self, cache_attr, getattr(f, attr))
return getattr(self, cache_attr)
def _get_m2m_reverse_attr(self, related, attr):
"""
Function that can be curried to provide the related accessor or DB
column name for the m2m table.
"""
cache_attr = '_m2m_reverse_%s_cache' % attr
if hasattr(self, cache_attr):
return getattr(self, cache_attr)
found = False
if self.remote_field.through_fields is not None:
link_field_name = self.remote_field.through_fields[1]
else:
link_field_name = None
for f in self.remote_field.through._meta.fields:
if f.is_relation and f.remote_field.model == related.model:
if link_field_name is None and related.related_model == related.model:
# If this is an m2m-intermediate to self,
# the first foreign key you find will be
# the source column. Keep searching for
# the second foreign key.
if found:
setattr(self, cache_attr, getattr(f, attr))
break
else:
found = True
elif link_field_name is None or link_field_name == f.name:
setattr(self, cache_attr, getattr(f, attr))
break
return getattr(self, cache_attr)
def contribute_to_class(self, cls, name, **kwargs):
# To support multiple relations to self, it's useful to have a non-None
# related name on symmetrical relations for internal reasons. The
# concept doesn't make a lot of sense externally ("you want me to
# specify *what* on my non-reversible relation?!"), so we set it up
# automatically. The funky name reduces the chance of an accidental
# clash.
if self.remote_field.symmetrical and (
self.remote_field.model == "self" or self.remote_field.model == cls._meta.object_name):
self.remote_field.related_name = "%s_rel_+" % name
elif self.remote_field.is_hidden():
# If the backwards relation is disabled, replace the original
# related_name with one generated from the m2m field name. Django
# still uses backwards relations internally and we need to avoid
# clashes between multiple m2m fields with related_name == '+'.
self.remote_field.related_name = "_%s_%s_+" % (cls.__name__.lower(), name)
super().contribute_to_class(cls, name, **kwargs)
# The intermediate m2m model is not auto created if:
# 1) There is a manually specified intermediate, or
# 2) The class owning the m2m field is abstract.
# 3) The class owning the m2m field has been swapped out.
if not cls._meta.abstract:
if self.remote_field.through:
def resolve_through_model(_, model, field):
field.remote_field.through = model
lazy_related_operation(resolve_through_model, cls, self.remote_field.through, field=self)
elif not cls._meta.swapped:
self.remote_field.through = create_many_to_many_intermediary_model(self, cls)
# Add the descriptor for the m2m relation.
setattr(cls, self.name, ManyToManyDescriptor(self.remote_field, reverse=False))
# Set up the accessor for the m2m table name for the relation.
self.m2m_db_table = partial(self._get_m2m_db_table, cls._meta)
def contribute_to_related_class(self, cls, related):
# Internal M2Ms (i.e., those with a related name ending with '+')
# and swapped models don't get a related descriptor.
if not self.remote_field.is_hidden() and not related.related_model._meta.swapped:
setattr(cls, related.get_accessor_name(), ManyToManyDescriptor(self.remote_field, reverse=True))
# Set up the accessors for the column names on the m2m table.
self.m2m_column_name = partial(self._get_m2m_attr, related, 'column')
self.m2m_reverse_name = partial(self._get_m2m_reverse_attr, related, 'column')
self.m2m_field_name = partial(self._get_m2m_attr, related, 'name')
self.m2m_reverse_field_name = partial(self._get_m2m_reverse_attr, related, 'name')
get_m2m_rel = partial(self._get_m2m_attr, related, 'remote_field')
self.m2m_target_field_name = lambda: get_m2m_rel().field_name
get_m2m_reverse_rel = partial(self._get_m2m_reverse_attr, related, 'remote_field')
self.m2m_reverse_target_field_name = lambda: get_m2m_reverse_rel().field_name
def set_attributes_from_rel(self):
pass
def value_from_object(self, obj):
return [] if obj.pk is None else list(getattr(obj, self.attname).all())
def save_form_data(self, instance, data):
getattr(instance, self.attname).set(data)
def formfield(self, *, using=None, **kwargs):
defaults = {
'form_class': forms.ModelMultipleChoiceField,
'queryset': self.remote_field.model._default_manager.using(using),
**kwargs,
}
# If initial is passed in, it's a list of related objects, but the
# MultipleChoiceField takes a list of IDs.
if defaults.get('initial') is not None:
initial = defaults['initial']
if callable(initial):
initial = initial()
defaults['initial'] = [i.pk for i in initial]
return super().formfield(**defaults)
def db_check(self, connection):
return None
def db_type(self, connection):
# A ManyToManyField is not represented by a single column,
# so return None.
return None
def db_parameters(self, connection):
return {"type": None, "check": None}
|
a1192012ab6fc5065ad066e0a5a289b9af3744acc798d592764276ee8265694d | import datetime
import posixpath
from django import forms
from django.core import checks
from django.core.files.base import File
from django.core.files.images import ImageFile
from django.core.files.storage import default_storage
from django.db.models import signals
from django.db.models.fields import Field
from django.utils.translation import gettext_lazy as _
class FieldFile(File):
def __init__(self, instance, field, name):
super().__init__(None, name)
self.instance = instance
self.field = field
self.storage = field.storage
self._committed = True
def __eq__(self, other):
# Older code may be expecting FileField values to be simple strings.
# By overriding the == operator, it can remain backwards compatibility.
if hasattr(other, 'name'):
return self.name == other.name
return self.name == other
def __hash__(self):
return hash(self.name)
# The standard File contains most of the necessary properties, but
# FieldFiles can be instantiated without a name, so that needs to
# be checked for here.
def _require_file(self):
if not self:
raise ValueError("The '%s' attribute has no file associated with it." % self.field.name)
def _get_file(self):
self._require_file()
if getattr(self, '_file', None) is None:
self._file = self.storage.open(self.name, 'rb')
return self._file
def _set_file(self, file):
self._file = file
def _del_file(self):
del self._file
file = property(_get_file, _set_file, _del_file)
@property
def path(self):
self._require_file()
return self.storage.path(self.name)
@property
def url(self):
self._require_file()
return self.storage.url(self.name)
@property
def size(self):
self._require_file()
if not self._committed:
return self.file.size
return self.storage.size(self.name)
def open(self, mode='rb'):
self._require_file()
if getattr(self, '_file', None) is None:
self.file = self.storage.open(self.name, mode)
else:
self.file.open(mode)
return self
# open() doesn't alter the file's contents, but it does reset the pointer
open.alters_data = True
# In addition to the standard File API, FieldFiles have extra methods
# to further manipulate the underlying file, as well as update the
# associated model instance.
def save(self, name, content, save=True):
name = self.field.generate_filename(self.instance, name)
self.name = self.storage.save(name, content, max_length=self.field.max_length)
setattr(self.instance, self.field.name, self.name)
self._committed = True
# Save the object because it has changed, unless save is False
if save:
self.instance.save()
save.alters_data = True
def delete(self, save=True):
if not self:
return
# Only close the file if it's already open, which we know by the
# presence of self._file
if hasattr(self, '_file'):
self.close()
del self.file
self.storage.delete(self.name)
self.name = None
setattr(self.instance, self.field.name, self.name)
self._committed = False
if save:
self.instance.save()
delete.alters_data = True
@property
def closed(self):
file = getattr(self, '_file', None)
return file is None or file.closed
def close(self):
file = getattr(self, '_file', None)
if file is not None:
file.close()
def __getstate__(self):
# FieldFile needs access to its associated model field and an instance
# it's attached to in order to work properly, but the only necessary
# data to be pickled is the file's name itself. Everything else will
# be restored later, by FileDescriptor below.
return {'name': self.name, 'closed': False, '_committed': True, '_file': None}
class FileDescriptor:
"""
The descriptor for the file attribute on the model instance. Return a
FieldFile when accessed so you can write code like::
>>> from myapp.models import MyModel
>>> instance = MyModel.objects.get(pk=1)
>>> instance.file.size
Assign a file object on assignment so you can do::
>>> with open('/path/to/hello.world', 'r') as f:
... instance.file = File(f)
"""
def __init__(self, field):
self.field = field
def __get__(self, instance, cls=None):
if instance is None:
return self
# This is slightly complicated, so worth an explanation.
# instance.file`needs to ultimately return some instance of `File`,
# probably a subclass. Additionally, this returned object needs to have
# the FieldFile API so that users can easily do things like
# instance.file.path and have that delegated to the file storage engine.
# Easy enough if we're strict about assignment in __set__, but if you
# peek below you can see that we're not. So depending on the current
# value of the field we have to dynamically construct some sort of
# "thing" to return.
# The instance dict contains whatever was originally assigned
# in __set__.
if self.field.name in instance.__dict__:
file = instance.__dict__[self.field.name]
else:
instance.refresh_from_db(fields=[self.field.name])
file = getattr(instance, self.field.name)
# If this value is a string (instance.file = "path/to/file") or None
# then we simply wrap it with the appropriate attribute class according
# to the file field. [This is FieldFile for FileFields and
# ImageFieldFile for ImageFields; it's also conceivable that user
# subclasses might also want to subclass the attribute class]. This
# object understands how to convert a path to a file, and also how to
# handle None.
if isinstance(file, str) or file is None:
attr = self.field.attr_class(instance, self.field, file)
instance.__dict__[self.field.name] = attr
# Other types of files may be assigned as well, but they need to have
# the FieldFile interface added to them. Thus, we wrap any other type of
# File inside a FieldFile (well, the field's attr_class, which is
# usually FieldFile).
elif isinstance(file, File) and not isinstance(file, FieldFile):
file_copy = self.field.attr_class(instance, self.field, file.name)
file_copy.file = file
file_copy._committed = False
instance.__dict__[self.field.name] = file_copy
# Finally, because of the (some would say boneheaded) way pickle works,
# the underlying FieldFile might not actually itself have an associated
# file. So we need to reset the details of the FieldFile in those cases.
elif isinstance(file, FieldFile) and not hasattr(file, 'field'):
file.instance = instance
file.field = self.field
file.storage = self.field.storage
# Make sure that the instance is correct.
elif isinstance(file, FieldFile) and instance is not file.instance:
file.instance = instance
# That was fun, wasn't it?
return instance.__dict__[self.field.name]
def __set__(self, instance, value):
instance.__dict__[self.field.name] = value
class FileField(Field):
# The class to wrap instance attributes in. Accessing the file object off
# the instance will always return an instance of attr_class.
attr_class = FieldFile
# The descriptor to use for accessing the attribute off of the class.
descriptor_class = FileDescriptor
description = _("File")
def __init__(self, verbose_name=None, name=None, upload_to='', storage=None, **kwargs):
self._primary_key_set_explicitly = 'primary_key' in kwargs
self.storage = storage or default_storage
self.upload_to = upload_to
kwargs.setdefault('max_length', 100)
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_primary_key(),
*self._check_upload_to(),
]
def _check_primary_key(self):
if self._primary_key_set_explicitly:
return [
checks.Error(
"'primary_key' is not a valid argument for a %s." % self.__class__.__name__,
obj=self,
id='fields.E201',
)
]
else:
return []
def _check_upload_to(self):
if isinstance(self.upload_to, str) and self.upload_to.startswith('/'):
return [
checks.Error(
"%s's 'upload_to' argument must be a relative path, not an "
"absolute path." % self.__class__.__name__,
obj=self,
id='fields.E202',
hint='Remove the leading slash.',
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if kwargs.get("max_length") == 100:
del kwargs["max_length"]
kwargs['upload_to'] = self.upload_to
if self.storage is not default_storage:
kwargs['storage'] = self.storage
return name, path, args, kwargs
def get_internal_type(self):
return "FileField"
def get_prep_value(self, value):
value = super().get_prep_value(value)
# Need to convert File objects provided via a form to string for database insertion
if value is None:
return None
return str(value)
def pre_save(self, model_instance, add):
file = super().pre_save(model_instance, add)
if file and not file._committed:
# Commit the file to storage prior to saving the model
file.save(file.name, file.file, save=False)
return file
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
setattr(cls, self.name, self.descriptor_class(self))
def generate_filename(self, instance, filename):
"""
Apply (if callable) or prepend (if a string) upload_to to the filename,
then delegate further processing of the name to the storage backend.
Until the storage layer, all file paths are expected to be Unix style
(with forward slashes).
"""
if callable(self.upload_to):
filename = self.upload_to(instance, filename)
else:
dirname = datetime.datetime.now().strftime(self.upload_to)
filename = posixpath.join(dirname, filename)
return self.storage.generate_filename(filename)
def save_form_data(self, instance, data):
# Important: None means "no change", other false value means "clear"
# This subtle distinction (rather than a more explicit marker) is
# needed because we need to consume values that are also sane for a
# regular (non Model-) Form to find in its cleaned_data dictionary.
if data is not None:
# This value will be converted to str and stored in the
# database, so leaving False as-is is not acceptable.
setattr(instance, self.name, data or '')
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.FileField,
'max_length': self.max_length,
**kwargs,
})
class ImageFileDescriptor(FileDescriptor):
"""
Just like the FileDescriptor, but for ImageFields. The only difference is
assigning the width/height to the width_field/height_field, if appropriate.
"""
def __set__(self, instance, value):
previous_file = instance.__dict__.get(self.field.name)
super().__set__(instance, value)
# To prevent recalculating image dimensions when we are instantiating
# an object from the database (bug #11084), only update dimensions if
# the field had a value before this assignment. Since the default
# value for FileField subclasses is an instance of field.attr_class,
# previous_file will only be None when we are called from
# Model.__init__(). The ImageField.update_dimension_fields method
# hooked up to the post_init signal handles the Model.__init__() cases.
# Assignment happening outside of Model.__init__() will trigger the
# update right here.
if previous_file is not None:
self.field.update_dimension_fields(instance, force=True)
class ImageFieldFile(ImageFile, FieldFile):
def delete(self, save=True):
# Clear the image dimensions cache
if hasattr(self, '_dimensions_cache'):
del self._dimensions_cache
super().delete(save)
class ImageField(FileField):
attr_class = ImageFieldFile
descriptor_class = ImageFileDescriptor
description = _("Image")
def __init__(self, verbose_name=None, name=None, width_field=None, height_field=None, **kwargs):
self.width_field, self.height_field = width_field, height_field
super().__init__(verbose_name, name, **kwargs)
def check(self, **kwargs):
return [
*super().check(**kwargs),
*self._check_image_library_installed(),
]
def _check_image_library_installed(self):
try:
from PIL import Image # NOQA
except ImportError:
return [
checks.Error(
'Cannot use ImageField because Pillow is not installed.',
hint=('Get Pillow at https://pypi.org/project/Pillow/ '
'or run command "pip install Pillow".'),
obj=self,
id='fields.E210',
)
]
else:
return []
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
if self.width_field:
kwargs['width_field'] = self.width_field
if self.height_field:
kwargs['height_field'] = self.height_field
return name, path, args, kwargs
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
# Attach update_dimension_fields so that dimension fields declared
# after their corresponding image field don't stay cleared by
# Model.__init__, see bug #11196.
# Only run post-initialization dimension update on non-abstract models
if not cls._meta.abstract:
signals.post_init.connect(self.update_dimension_fields, sender=cls)
def update_dimension_fields(self, instance, force=False, *args, **kwargs):
"""
Update field's width and height fields, if defined.
This method is hooked up to model's post_init signal to update
dimensions after instantiating a model instance. However, dimensions
won't be updated if the dimensions fields are already populated. This
avoids unnecessary recalculation when loading an object from the
database.
Dimensions can be forced to update with force=True, which is how
ImageFileDescriptor.__set__ calls this method.
"""
# Nothing to update if the field doesn't have dimension fields or if
# the field is deferred.
has_dimension_fields = self.width_field or self.height_field
if not has_dimension_fields or self.attname not in instance.__dict__:
return
# getattr will call the ImageFileDescriptor's __get__ method, which
# coerces the assigned value into an instance of self.attr_class
# (ImageFieldFile in this case).
file = getattr(instance, self.attname)
# Nothing to update if we have no file and not being forced to update.
if not file and not force:
return
dimension_fields_filled = not(
(self.width_field and not getattr(instance, self.width_field)) or
(self.height_field and not getattr(instance, self.height_field))
)
# When both dimension fields have values, we are most likely loading
# data from the database or updating an image field that already had
# an image stored. In the first case, we don't want to update the
# dimension fields because we are already getting their values from the
# database. In the second case, we do want to update the dimensions
# fields and will skip this return because force will be True since we
# were called from ImageFileDescriptor.__set__.
if dimension_fields_filled and not force:
return
# file should be an instance of ImageFieldFile or should be None.
if file:
width = file.width
height = file.height
else:
# No file, so clear dimensions fields.
width = None
height = None
# Update the width and height fields.
if self.width_field:
setattr(instance, self.width_field, width)
if self.height_field:
setattr(instance, self.height_field, height)
def formfield(self, **kwargs):
return super().formfield(**{
'form_class': forms.ImageField,
**kwargs,
})
|
e4292ae1dd5c64e0c77d588b19c532b89c2f54fc95f8a7ddd9a649cd8e1c9317 | NOT_PROVIDED = object()
class FieldCacheMixin:
"""Provide an API for working with the model's fields value cache."""
def get_cache_name(self):
raise NotImplementedError
def get_cached_value(self, instance, default=NOT_PROVIDED):
cache_name = self.get_cache_name()
try:
return instance._state.fields_cache[cache_name]
except KeyError:
if default is NOT_PROVIDED:
raise
return default
def is_cached(self, instance):
return self.get_cache_name() in instance._state.fields_cache
def set_cached_value(self, instance, value):
instance._state.fields_cache[self.get_cache_name()] = value
def delete_cached_value(self, instance):
del instance._state.fields_cache[self.get_cache_name()]
|
eac9db43e58707e0c6cf57df48c859129bff17688f6ec306c9a0bc607235e72e | """
Accessors for related objects.
When a field defines a relation between two models, each model class provides
an attribute to access related instances of the other model class (unless the
reverse accessor has been disabled with related_name='+').
Accessors are implemented as descriptors in order to customize access and
assignment. This module defines the descriptor classes.
Forward accessors follow foreign keys. Reverse accessors trace them back. For
example, with the following models::
class Parent(Model):
pass
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``child.parent`` is a forward many-to-one relation. ``parent.children`` is a
reverse many-to-one relation.
There are three types of relations (many-to-one, one-to-one, and many-to-many)
and two directions (forward and reverse) for a total of six combinations.
1. Related instance on the forward side of a many-to-one relation:
``ForwardManyToOneDescriptor``.
Uniqueness of foreign key values is irrelevant to accessing the related
instance, making the many-to-one and one-to-one cases identical as far as
the descriptor is concerned. The constraint is checked upstream (unicity
validation in forms) or downstream (unique indexes in the database).
2. Related instance on the forward side of a one-to-one
relation: ``ForwardOneToOneDescriptor``.
It avoids querying the database when accessing the parent link field in
a multi-table inheritance scenario.
3. Related instance on the reverse side of a one-to-one relation:
``ReverseOneToOneDescriptor``.
One-to-one relations are asymmetrical, despite the apparent symmetry of the
name, because they're implemented in the database with a foreign key from
one table to another. As a consequence ``ReverseOneToOneDescriptor`` is
slightly different from ``ForwardManyToOneDescriptor``.
4. Related objects manager for related instances on the reverse side of a
many-to-one relation: ``ReverseManyToOneDescriptor``.
Unlike the previous two classes, this one provides access to a collection
of objects. It returns a manager rather than an instance.
5. Related objects manager for related instances on the forward or reverse
sides of a many-to-many relation: ``ManyToManyDescriptor``.
Many-to-many relations are symmetrical. The syntax of Django models
requires declaring them on one side but that's an implementation detail.
They could be declared on the other side without any change in behavior.
Therefore the forward and reverse descriptors can be the same.
If you're looking for ``ForwardManyToManyDescriptor`` or
``ReverseManyToManyDescriptor``, use ``ManyToManyDescriptor`` instead.
"""
from django.db import connections, router, transaction
from django.db.models import Q, signals
from django.db.models.query import QuerySet
from django.utils.functional import cached_property
class ForwardManyToOneDescriptor:
"""
Accessor to the related object on the forward side of a many-to-one or
one-to-one (via ForwardOneToOneDescriptor subclass) relation.
In the example::
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``Child.parent`` is a ``ForwardManyToOneDescriptor`` instance.
"""
def __init__(self, field_with_rel):
self.field = field_with_rel
@cached_property
def RelatedObjectDoesNotExist(self):
# The exception can't be created at initialization time since the
# related model might not be resolved yet; `self.field.model` might
# still be a string model reference.
return type(
'RelatedObjectDoesNotExist',
(self.field.remote_field.model.DoesNotExist, AttributeError), {
'__module__': self.field.model.__module__,
'__qualname__': '%s.%s.RelatedObjectDoesNotExist' % (
self.field.model.__qualname__,
self.field.name,
),
}
)
def is_cached(self, instance):
return self.field.is_cached(instance)
def get_queryset(self, **hints):
return self.field.remote_field.model._base_manager.db_manager(hints=hints).all()
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = self.get_queryset()
queryset._add_hints(instance=instances[0])
rel_obj_attr = self.field.get_foreign_related_value
instance_attr = self.field.get_local_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
related_field = self.field.foreign_related_fields[0]
remote_field = self.field.remote_field
# FIXME: This will need to be revisited when we introduce support for
# composite fields. In the meantime we take this practical approach to
# solve a regression on 1.6 when the reverse manager in hidden
# (related_name ends with a '+'). Refs #21410.
# The check for len(...) == 1 is a special case that allows the query
# to be join-less and smaller. Refs #21760.
if remote_field.is_hidden() or len(self.field.foreign_related_fields) == 1:
query = {'%s__in' % related_field.name: {instance_attr(inst)[0] for inst in instances}}
else:
query = {'%s__in' % self.field.related_query_name(): instances}
queryset = queryset.filter(**query)
# Since we're going to assign directly in the cache,
# we must manage the reverse relation cache manually.
if not remote_field.multiple:
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
remote_field.set_cached_value(rel_obj, instance)
return queryset, rel_obj_attr, instance_attr, True, self.field.get_cache_name(), False
def get_object(self, instance):
qs = self.get_queryset(instance=instance)
# Assuming the database enforces foreign keys, this won't fail.
return qs.get(self.field.get_reverse_related_filter(instance))
def __get__(self, instance, cls=None):
"""
Get the related instance through the forward relation.
With the example above, when getting ``child.parent``:
- ``self`` is the descriptor managing the ``parent`` attribute
- ``instance`` is the ``child`` instance
- ``cls`` is the ``Child`` class (we don't need it)
"""
if instance is None:
return self
# The related instance is loaded from the database and then cached
# by the field on the model instance state. It can also be pre-cached
# by the reverse accessor (ReverseOneToOneDescriptor).
try:
rel_obj = self.field.get_cached_value(instance)
except KeyError:
has_value = None not in self.field.get_local_related_value(instance)
ancestor_link = instance._meta.get_ancestor_link(self.field.model) if has_value else None
if ancestor_link and ancestor_link.is_cached(instance):
# An ancestor link will exist if this field is defined on a
# multi-table inheritance parent of the instance's class.
ancestor = ancestor_link.get_cached_value(instance)
# The value might be cached on an ancestor if the instance
# originated from walking down the inheritance chain.
rel_obj = self.field.get_cached_value(ancestor, default=None)
else:
rel_obj = None
if rel_obj is None and has_value:
rel_obj = self.get_object(instance)
remote_field = self.field.remote_field
# If this is a one-to-one relation, set the reverse accessor
# cache on the related object to the current instance to avoid
# an extra SQL query if it's accessed later on.
if not remote_field.multiple:
remote_field.set_cached_value(rel_obj, instance)
self.field.set_cached_value(instance, rel_obj)
if rel_obj is None and not self.field.null:
raise self.RelatedObjectDoesNotExist(
"%s has no %s." % (self.field.model.__name__, self.field.name)
)
else:
return rel_obj
def __set__(self, instance, value):
"""
Set the related instance through the forward relation.
With the example above, when setting ``child.parent = parent``:
- ``self`` is the descriptor managing the ``parent`` attribute
- ``instance`` is the ``child`` instance
- ``value`` is the ``parent`` instance on the right of the equal sign
"""
# An object must be an instance of the related class.
if value is not None and not isinstance(value, self.field.remote_field.model._meta.concrete_model):
raise ValueError(
'Cannot assign "%r": "%s.%s" must be a "%s" instance.' % (
value,
instance._meta.object_name,
self.field.name,
self.field.remote_field.model._meta.object_name,
)
)
elif value is not None:
if instance._state.db is None:
instance._state.db = router.db_for_write(instance.__class__, instance=value)
if value._state.db is None:
value._state.db = router.db_for_write(value.__class__, instance=instance)
if not router.allow_relation(value, instance):
raise ValueError('Cannot assign "%r": the current database router prevents this relation.' % value)
remote_field = self.field.remote_field
# If we're setting the value of a OneToOneField to None, we need to clear
# out the cache on any old related object. Otherwise, deleting the
# previously-related object will also cause this object to be deleted,
# which is wrong.
if value is None:
# Look up the previously-related object, which may still be available
# since we've not yet cleared out the related field.
# Use the cache directly, instead of the accessor; if we haven't
# populated the cache, then we don't care - we're only accessing
# the object to invalidate the accessor cache, so there's no
# need to populate the cache just to expire it again.
related = self.field.get_cached_value(instance, default=None)
# If we've got an old related object, we need to clear out its
# cache. This cache also might not exist if the related object
# hasn't been accessed yet.
if related is not None:
remote_field.set_cached_value(related, None)
for lh_field, rh_field in self.field.related_fields:
setattr(instance, lh_field.attname, None)
# Set the values of the related field.
else:
for lh_field, rh_field in self.field.related_fields:
setattr(instance, lh_field.attname, getattr(value, rh_field.attname))
# Set the related instance cache used by __get__ to avoid an SQL query
# when accessing the attribute we just set.
self.field.set_cached_value(instance, value)
# If this is a one-to-one relation, set the reverse accessor cache on
# the related object to the current instance to avoid an extra SQL
# query if it's accessed later on.
if value is not None and not remote_field.multiple:
remote_field.set_cached_value(value, instance)
def __reduce__(self):
"""
Pickling should return the instance attached by self.field on the
model, not a new copy of that descriptor. Use getattr() to retrieve
the instance directly from the model.
"""
return getattr, (self.field.model, self.field.name)
class ForwardOneToOneDescriptor(ForwardManyToOneDescriptor):
"""
Accessor to the related object on the forward side of a one-to-one relation.
In the example::
class Restaurant(Model):
place = OneToOneField(Place, related_name='restaurant')
``Restaurant.place`` is a ``ForwardOneToOneDescriptor`` instance.
"""
def get_object(self, instance):
if self.field.remote_field.parent_link:
deferred = instance.get_deferred_fields()
# Because it's a parent link, all the data is available in the
# instance, so populate the parent model with this data.
rel_model = self.field.remote_field.model
fields = [field.attname for field in rel_model._meta.concrete_fields]
# If any of the related model's fields are deferred, fallback to
# fetching all fields from the related model. This avoids a query
# on the related model for every deferred field.
if not any(field in fields for field in deferred):
kwargs = {field: getattr(instance, field) for field in fields}
obj = rel_model(**kwargs)
obj._state.adding = instance._state.adding
obj._state.db = instance._state.db
return obj
return super().get_object(instance)
def __set__(self, instance, value):
super().__set__(instance, value)
# If the primary key is a link to a parent model and a parent instance
# is being set, update the value of the inherited pk(s).
if self.field.primary_key and self.field.remote_field.parent_link:
opts = instance._meta
# Inherited primary key fields from this object's base classes.
inherited_pk_fields = [
field for field in opts.concrete_fields
if field.primary_key and field.remote_field
]
for field in inherited_pk_fields:
rel_model_pk_name = field.remote_field.model._meta.pk.attname
raw_value = getattr(value, rel_model_pk_name) if value is not None else None
setattr(instance, rel_model_pk_name, raw_value)
class ReverseOneToOneDescriptor:
"""
Accessor to the related object on the reverse side of a one-to-one
relation.
In the example::
class Restaurant(Model):
place = OneToOneField(Place, related_name='restaurant')
``Place.restaurant`` is a ``ReverseOneToOneDescriptor`` instance.
"""
def __init__(self, related):
# Following the example above, `related` is an instance of OneToOneRel
# which represents the reverse restaurant field (place.restaurant).
self.related = related
@cached_property
def RelatedObjectDoesNotExist(self):
# The exception isn't created at initialization time for the sake of
# consistency with `ForwardManyToOneDescriptor`.
return type(
'RelatedObjectDoesNotExist',
(self.related.related_model.DoesNotExist, AttributeError), {
'__module__': self.related.model.__module__,
'__qualname__': '%s.%s.RelatedObjectDoesNotExist' % (
self.related.model.__qualname__,
self.related.name,
)
},
)
def is_cached(self, instance):
return self.related.is_cached(instance)
def get_queryset(self, **hints):
return self.related.related_model._base_manager.db_manager(hints=hints).all()
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = self.get_queryset()
queryset._add_hints(instance=instances[0])
rel_obj_attr = self.related.field.get_local_related_value
instance_attr = self.related.field.get_foreign_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
query = {'%s__in' % self.related.field.name: instances}
queryset = queryset.filter(**query)
# Since we're going to assign directly in the cache,
# we must manage the reverse relation cache manually.
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
self.related.field.set_cached_value(rel_obj, instance)
return queryset, rel_obj_attr, instance_attr, True, self.related.get_cache_name(), False
def __get__(self, instance, cls=None):
"""
Get the related instance through the reverse relation.
With the example above, when getting ``place.restaurant``:
- ``self`` is the descriptor managing the ``restaurant`` attribute
- ``instance`` is the ``place`` instance
- ``cls`` is the ``Place`` class (unused)
Keep in mind that ``Restaurant`` holds the foreign key to ``Place``.
"""
if instance is None:
return self
# The related instance is loaded from the database and then cached
# by the field on the model instance state. It can also be pre-cached
# by the forward accessor (ForwardManyToOneDescriptor).
try:
rel_obj = self.related.get_cached_value(instance)
except KeyError:
related_pk = instance.pk
if related_pk is None:
rel_obj = None
else:
filter_args = self.related.field.get_forward_related_filter(instance)
try:
rel_obj = self.get_queryset(instance=instance).get(**filter_args)
except self.related.related_model.DoesNotExist:
rel_obj = None
else:
# Set the forward accessor cache on the related object to
# the current instance to avoid an extra SQL query if it's
# accessed later on.
self.related.field.set_cached_value(rel_obj, instance)
self.related.set_cached_value(instance, rel_obj)
if rel_obj is None:
raise self.RelatedObjectDoesNotExist(
"%s has no %s." % (
instance.__class__.__name__,
self.related.get_accessor_name()
)
)
else:
return rel_obj
def __set__(self, instance, value):
"""
Set the related instance through the reverse relation.
With the example above, when setting ``place.restaurant = restaurant``:
- ``self`` is the descriptor managing the ``restaurant`` attribute
- ``instance`` is the ``place`` instance
- ``value`` is the ``restaurant`` instance on the right of the equal sign
Keep in mind that ``Restaurant`` holds the foreign key to ``Place``.
"""
# The similarity of the code below to the code in
# ForwardManyToOneDescriptor is annoying, but there's a bunch
# of small differences that would make a common base class convoluted.
if value is None:
# Update the cached related instance (if any) & clear the cache.
# Following the example above, this would be the cached
# ``restaurant`` instance (if any).
rel_obj = self.related.get_cached_value(instance, default=None)
if rel_obj is not None:
# Remove the ``restaurant`` instance from the ``place``
# instance cache.
self.related.delete_cached_value(instance)
# Set the ``place`` field on the ``restaurant``
# instance to None.
setattr(rel_obj, self.related.field.name, None)
elif not isinstance(value, self.related.related_model):
# An object must be an instance of the related class.
raise ValueError(
'Cannot assign "%r": "%s.%s" must be a "%s" instance.' % (
value,
instance._meta.object_name,
self.related.get_accessor_name(),
self.related.related_model._meta.object_name,
)
)
else:
if instance._state.db is None:
instance._state.db = router.db_for_write(instance.__class__, instance=value)
if value._state.db is None:
value._state.db = router.db_for_write(value.__class__, instance=instance)
if not router.allow_relation(value, instance):
raise ValueError('Cannot assign "%r": the current database router prevents this relation.' % value)
related_pk = tuple(getattr(instance, field.attname) for field in self.related.field.foreign_related_fields)
# Set the value of the related field to the value of the related object's related field
for index, field in enumerate(self.related.field.local_related_fields):
setattr(value, field.attname, related_pk[index])
# Set the related instance cache used by __get__ to avoid an SQL query
# when accessing the attribute we just set.
self.related.set_cached_value(instance, value)
# Set the forward accessor cache on the related object to the current
# instance to avoid an extra SQL query if it's accessed later on.
self.related.field.set_cached_value(value, instance)
def __reduce__(self):
# Same purpose as ForwardManyToOneDescriptor.__reduce__().
return getattr, (self.related.model, self.related.name)
class ReverseManyToOneDescriptor:
"""
Accessor to the related objects manager on the reverse side of a
many-to-one relation.
In the example::
class Child(Model):
parent = ForeignKey(Parent, related_name='children')
``Parent.children`` is a ``ReverseManyToOneDescriptor`` instance.
Most of the implementation is delegated to a dynamically defined manager
class built by ``create_forward_many_to_many_manager()`` defined below.
"""
def __init__(self, rel):
self.rel = rel
self.field = rel.field
@cached_property
def related_manager_cls(self):
related_model = self.rel.related_model
return create_reverse_many_to_one_manager(
related_model._default_manager.__class__,
self.rel,
)
def __get__(self, instance, cls=None):
"""
Get the related objects through the reverse relation.
With the example above, when getting ``parent.children``:
- ``self`` is the descriptor managing the ``children`` attribute
- ``instance`` is the ``parent`` instance
- ``cls`` is the ``Parent`` class (unused)
"""
if instance is None:
return self
return self.related_manager_cls(instance)
def _get_set_deprecation_msg_params(self):
return (
'reverse side of a related set',
self.rel.get_accessor_name(),
)
def __set__(self, instance, value):
raise TypeError(
'Direct assignment to the %s is prohibited. Use %s.set() instead.'
% self._get_set_deprecation_msg_params(),
)
def create_reverse_many_to_one_manager(superclass, rel):
"""
Create a manager for the reverse side of a many-to-one relation.
This manager subclasses another manager, generally the default manager of
the related model, and adds behaviors specific to many-to-one relations.
"""
class RelatedManager(superclass):
def __init__(self, instance):
super().__init__()
self.instance = instance
self.model = rel.related_model
self.field = rel.field
self.core_filters = {self.field.name: instance}
def __call__(self, *, manager):
manager = getattr(self.model, manager)
manager_class = create_reverse_many_to_one_manager(manager.__class__, rel)
return manager_class(self.instance)
do_not_call_in_templates = True
def _apply_rel_filters(self, queryset):
"""
Filter the queryset for the instance this manager is bound to.
"""
db = self._db or router.db_for_read(self.model, instance=self.instance)
empty_strings_as_null = connections[db].features.interprets_empty_strings_as_nulls
queryset._add_hints(instance=self.instance)
if self._db:
queryset = queryset.using(self._db)
queryset = queryset.filter(**self.core_filters)
for field in self.field.foreign_related_fields:
val = getattr(self.instance, field.attname)
if val is None or (val == '' and empty_strings_as_null):
return queryset.none()
queryset._known_related_objects = {self.field: {self.instance.pk: self.instance}}
return queryset
def _remove_prefetched_objects(self):
try:
self.instance._prefetched_objects_cache.pop(self.field.remote_field.get_cache_name())
except (AttributeError, KeyError):
pass # nothing to clear from cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.field.remote_field.get_cache_name()]
except (AttributeError, KeyError):
queryset = super().get_queryset()
return self._apply_rel_filters(queryset)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = super().get_queryset()
queryset._add_hints(instance=instances[0])
queryset = queryset.using(queryset._db or self._db)
rel_obj_attr = self.field.get_local_related_value
instance_attr = self.field.get_foreign_related_value
instances_dict = {instance_attr(inst): inst for inst in instances}
query = {'%s__in' % self.field.name: instances}
queryset = queryset.filter(**query)
# Since we just bypassed this class' get_queryset(), we must manage
# the reverse relation manually.
for rel_obj in queryset:
instance = instances_dict[rel_obj_attr(rel_obj)]
setattr(rel_obj, self.field.name, instance)
cache_name = self.field.remote_field.get_cache_name()
return queryset, rel_obj_attr, instance_attr, False, cache_name, False
def add(self, *objs, bulk=True):
self._remove_prefetched_objects()
objs = list(objs)
db = router.db_for_write(self.model, instance=self.instance)
def check_and_update_obj(obj):
if not isinstance(obj, self.model):
raise TypeError("'%s' instance expected, got %r" % (
self.model._meta.object_name, obj,
))
setattr(obj, self.field.name, self.instance)
if bulk:
pks = []
for obj in objs:
check_and_update_obj(obj)
if obj._state.adding or obj._state.db != db:
raise ValueError(
"%r instance isn't saved. Use bulk=False or save "
"the object first." % obj
)
pks.append(obj.pk)
self.model._base_manager.using(db).filter(pk__in=pks).update(**{
self.field.name: self.instance,
})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in objs:
check_and_update_obj(obj)
obj.save()
add.alters_data = True
def create(self, **kwargs):
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).create(**kwargs)
create.alters_data = True
def get_or_create(self, **kwargs):
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).get_or_create(**kwargs)
get_or_create.alters_data = True
def update_or_create(self, **kwargs):
kwargs[self.field.name] = self.instance
db = router.db_for_write(self.model, instance=self.instance)
return super(RelatedManager, self.db_manager(db)).update_or_create(**kwargs)
update_or_create.alters_data = True
# remove() and clear() are only provided if the ForeignKey can have a value of null.
if rel.field.null:
def remove(self, *objs, bulk=True):
if not objs:
return
val = self.field.get_foreign_related_value(self.instance)
old_ids = set()
for obj in objs:
# Is obj actually part of this descriptor set?
if self.field.get_local_related_value(obj) == val:
old_ids.add(obj.pk)
else:
raise self.field.remote_field.model.DoesNotExist(
"%r is not related to %r." % (obj, self.instance)
)
self._clear(self.filter(pk__in=old_ids), bulk)
remove.alters_data = True
def clear(self, *, bulk=True):
self._clear(self, bulk)
clear.alters_data = True
def _clear(self, queryset, bulk):
self._remove_prefetched_objects()
db = router.db_for_write(self.model, instance=self.instance)
queryset = queryset.using(db)
if bulk:
# `QuerySet.update()` is intrinsically atomic.
queryset.update(**{self.field.name: None})
else:
with transaction.atomic(using=db, savepoint=False):
for obj in queryset:
setattr(obj, self.field.name, None)
obj.save(update_fields=[self.field.name])
_clear.alters_data = True
def set(self, objs, *, bulk=True, clear=False):
# Force evaluation of `objs` in case it's a queryset whose value
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
if self.field.null:
db = router.db_for_write(self.model, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear(bulk=bulk)
self.add(*objs, bulk=bulk)
else:
old_objs = set(self.using(db).all())
new_objs = []
for obj in objs:
if obj in old_objs:
old_objs.remove(obj)
else:
new_objs.append(obj)
self.remove(*old_objs, bulk=bulk)
self.add(*new_objs, bulk=bulk)
else:
self.add(*objs, bulk=bulk)
set.alters_data = True
return RelatedManager
class ManyToManyDescriptor(ReverseManyToOneDescriptor):
"""
Accessor to the related objects manager on the forward and reverse sides of
a many-to-many relation.
In the example::
class Pizza(Model):
toppings = ManyToManyField(Topping, related_name='pizzas')
``Pizza.toppings`` and ``Topping.pizzas`` are ``ManyToManyDescriptor``
instances.
Most of the implementation is delegated to a dynamically defined manager
class built by ``create_forward_many_to_many_manager()`` defined below.
"""
def __init__(self, rel, reverse=False):
super().__init__(rel)
self.reverse = reverse
@property
def through(self):
# through is provided so that you have easy access to the through
# model (Book.authors.through) for inlines, etc. This is done as
# a property to ensure that the fully resolved value is returned.
return self.rel.through
@cached_property
def related_manager_cls(self):
related_model = self.rel.related_model if self.reverse else self.rel.model
return create_forward_many_to_many_manager(
related_model._default_manager.__class__,
self.rel,
reverse=self.reverse,
)
def _get_set_deprecation_msg_params(self):
return (
'%s side of a many-to-many set' % ('reverse' if self.reverse else 'forward'),
self.rel.get_accessor_name() if self.reverse else self.field.name,
)
def create_forward_many_to_many_manager(superclass, rel, reverse):
"""
Create a manager for the either side of a many-to-many relation.
This manager subclasses another manager, generally the default manager of
the related model, and adds behaviors specific to many-to-many relations.
"""
class ManyRelatedManager(superclass):
def __init__(self, instance=None):
super().__init__()
self.instance = instance
if not reverse:
self.model = rel.model
self.query_field_name = rel.field.related_query_name()
self.prefetch_cache_name = rel.field.name
self.source_field_name = rel.field.m2m_field_name()
self.target_field_name = rel.field.m2m_reverse_field_name()
self.symmetrical = rel.symmetrical
else:
self.model = rel.related_model
self.query_field_name = rel.field.name
self.prefetch_cache_name = rel.field.related_query_name()
self.source_field_name = rel.field.m2m_reverse_field_name()
self.target_field_name = rel.field.m2m_field_name()
self.symmetrical = False
self.through = rel.through
self.reverse = reverse
self.source_field = self.through._meta.get_field(self.source_field_name)
self.target_field = self.through._meta.get_field(self.target_field_name)
self.core_filters = {}
self.pk_field_names = {}
for lh_field, rh_field in self.source_field.related_fields:
core_filter_key = '%s__%s' % (self.query_field_name, rh_field.name)
self.core_filters[core_filter_key] = getattr(instance, rh_field.attname)
self.pk_field_names[lh_field.name] = rh_field.name
self.related_val = self.source_field.get_foreign_related_value(instance)
if None in self.related_val:
raise ValueError('"%r" needs to have a value for field "%s" before '
'this many-to-many relationship can be used.' %
(instance, self.pk_field_names[self.source_field_name]))
# Even if this relation is not to pk, we require still pk value.
# The wish is that the instance has been already saved to DB,
# although having a pk value isn't a guarantee of that.
if instance.pk is None:
raise ValueError("%r instance needs to have a primary key value before "
"a many-to-many relationship can be used." %
instance.__class__.__name__)
def __call__(self, *, manager):
manager = getattr(self.model, manager)
manager_class = create_forward_many_to_many_manager(manager.__class__, rel, reverse)
return manager_class(instance=self.instance)
do_not_call_in_templates = True
def _build_remove_filters(self, removed_vals):
filters = Q(**{self.source_field_name: self.related_val})
# No need to add a subquery condition if removed_vals is a QuerySet without
# filters.
removed_vals_filters = (not isinstance(removed_vals, QuerySet) or
removed_vals._has_filters())
if removed_vals_filters:
filters &= Q(**{'%s__in' % self.target_field_name: removed_vals})
if self.symmetrical:
symmetrical_filters = Q(**{self.target_field_name: self.related_val})
if removed_vals_filters:
symmetrical_filters &= Q(
**{'%s__in' % self.source_field_name: removed_vals})
filters |= symmetrical_filters
return filters
def _apply_rel_filters(self, queryset):
"""
Filter the queryset for the instance this manager is bound to.
"""
queryset._add_hints(instance=self.instance)
if self._db:
queryset = queryset.using(self._db)
return queryset._next_is_sticky().filter(**self.core_filters)
def _remove_prefetched_objects(self):
try:
self.instance._prefetched_objects_cache.pop(self.prefetch_cache_name)
except (AttributeError, KeyError):
pass # nothing to clear from cache
def get_queryset(self):
try:
return self.instance._prefetched_objects_cache[self.prefetch_cache_name]
except (AttributeError, KeyError):
queryset = super().get_queryset()
return self._apply_rel_filters(queryset)
def get_prefetch_queryset(self, instances, queryset=None):
if queryset is None:
queryset = super().get_queryset()
queryset._add_hints(instance=instances[0])
queryset = queryset.using(queryset._db or self._db)
query = {'%s__in' % self.query_field_name: instances}
queryset = queryset._next_is_sticky().filter(**query)
# M2M: need to annotate the query in order to get the primary model
# that the secondary model was actually related to. We know that
# there will already be a join on the join table, so we can just add
# the select.
# For non-autocreated 'through' models, can't assume we are
# dealing with PK values.
fk = self.through._meta.get_field(self.source_field_name)
join_table = fk.model._meta.db_table
connection = connections[queryset.db]
qn = connection.ops.quote_name
queryset = queryset.extra(select={
'_prefetch_related_val_%s' % f.attname:
'%s.%s' % (qn(join_table), qn(f.column)) for f in fk.local_related_fields})
return (
queryset,
lambda result: tuple(
getattr(result, '_prefetch_related_val_%s' % f.attname)
for f in fk.local_related_fields
),
lambda inst: tuple(
f.get_db_prep_value(getattr(inst, f.attname), connection)
for f in fk.foreign_related_fields
),
False,
self.prefetch_cache_name,
False,
)
def add(self, *objs):
if not rel.through._meta.auto_created:
opts = self.through._meta
raise AttributeError(
"Cannot use add() on a ManyToManyField which specifies an "
"intermediary model. Use %s.%s's Manager instead." %
(opts.app_label, opts.object_name)
)
self._remove_prefetched_objects()
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
self._add_items(self.source_field_name, self.target_field_name, *objs)
# If this is a symmetrical m2m relation to self, add the mirror entry in the m2m table
if self.symmetrical:
self._add_items(self.target_field_name, self.source_field_name, *objs)
add.alters_data = True
def remove(self, *objs):
if not rel.through._meta.auto_created:
opts = self.through._meta
raise AttributeError(
"Cannot use remove() on a ManyToManyField which specifies "
"an intermediary model. Use %s.%s's Manager instead." %
(opts.app_label, opts.object_name)
)
self._remove_prefetched_objects()
self._remove_items(self.source_field_name, self.target_field_name, *objs)
remove.alters_data = True
def clear(self):
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
signals.m2m_changed.send(
sender=self.through, action="pre_clear",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=None, using=db,
)
self._remove_prefetched_objects()
filters = self._build_remove_filters(super().get_queryset().using(db))
self.through._default_manager.using(db).filter(filters).delete()
signals.m2m_changed.send(
sender=self.through, action="post_clear",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=None, using=db,
)
clear.alters_data = True
def set(self, objs, *, clear=False):
if not rel.through._meta.auto_created:
opts = self.through._meta
raise AttributeError(
"Cannot set values on a ManyToManyField which specifies an "
"intermediary model. Use %s.%s's Manager instead." %
(opts.app_label, opts.object_name)
)
# Force evaluation of `objs` in case it's a queryset whose value
# could be affected by `manager.clear()`. Refs #19816.
objs = tuple(objs)
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
if clear:
self.clear()
self.add(*objs)
else:
old_ids = set(self.using(db).values_list(self.target_field.target_field.attname, flat=True))
new_objs = []
for obj in objs:
fk_val = (
self.target_field.get_foreign_related_value(obj)[0]
if isinstance(obj, self.model) else obj
)
if fk_val in old_ids:
old_ids.remove(fk_val)
else:
new_objs.append(obj)
self.remove(*old_ids)
self.add(*new_objs)
set.alters_data = True
def create(self, **kwargs):
# This check needs to be done here, since we can't later remove this
# from the method lookup table, as we do with add and remove.
if not self.through._meta.auto_created:
opts = self.through._meta
raise AttributeError(
"Cannot use create() on a ManyToManyField which specifies "
"an intermediary model. Use %s.%s's Manager instead." %
(opts.app_label, opts.object_name)
)
db = router.db_for_write(self.instance.__class__, instance=self.instance)
new_obj = super(ManyRelatedManager, self.db_manager(db)).create(**kwargs)
self.add(new_obj)
return new_obj
create.alters_data = True
def get_or_create(self, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
obj, created = super(ManyRelatedManager, self.db_manager(db)).get_or_create(**kwargs)
# We only need to add() if created because if we got an object back
# from get() then the relationship already exists.
if created:
self.add(obj)
return obj, created
get_or_create.alters_data = True
def update_or_create(self, **kwargs):
db = router.db_for_write(self.instance.__class__, instance=self.instance)
obj, created = super(ManyRelatedManager, self.db_manager(db)).update_or_create(**kwargs)
# We only need to add() if created because if we got an object back
# from get() then the relationship already exists.
if created:
self.add(obj)
return obj, created
update_or_create.alters_data = True
def _add_items(self, source_field_name, target_field_name, *objs):
# source_field_name: the PK fieldname in join table for the source object
# target_field_name: the PK fieldname in join table for the target object
# *objs - objects to add. Either object instances, or primary keys of object instances.
# If there aren't any objects, there is nothing to do.
from django.db.models import Model
if objs:
new_ids = set()
for obj in objs:
if isinstance(obj, self.model):
if not router.allow_relation(obj, self.instance):
raise ValueError(
'Cannot add "%r": instance is on database "%s", value is on database "%s"' %
(obj, self.instance._state.db, obj._state.db)
)
fk_val = self.through._meta.get_field(
target_field_name).get_foreign_related_value(obj)[0]
if fk_val is None:
raise ValueError(
'Cannot add "%r": the value for field "%s" is None' %
(obj, target_field_name)
)
new_ids.add(fk_val)
elif isinstance(obj, Model):
raise TypeError(
"'%s' instance expected, got %r" %
(self.model._meta.object_name, obj)
)
else:
new_ids.add(obj)
db = router.db_for_write(self.through, instance=self.instance)
vals = (self.through._default_manager.using(db)
.values_list(target_field_name, flat=True)
.filter(**{
source_field_name: self.related_val[0],
'%s__in' % target_field_name: new_ids,
}))
new_ids.difference_update(vals)
with transaction.atomic(using=db, savepoint=False):
if self.reverse or source_field_name == self.source_field_name:
# Don't send the signal when we are inserting the
# duplicate data row for symmetrical reverse entries.
signals.m2m_changed.send(
sender=self.through, action='pre_add',
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=new_ids, using=db,
)
# Add the ones that aren't there already
self.through._default_manager.using(db).bulk_create([
self.through(**{
'%s_id' % source_field_name: self.related_val[0],
'%s_id' % target_field_name: obj_id,
})
for obj_id in new_ids
])
if self.reverse or source_field_name == self.source_field_name:
# Don't send the signal when we are inserting the
# duplicate data row for symmetrical reverse entries.
signals.m2m_changed.send(
sender=self.through, action='post_add',
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=new_ids, using=db,
)
def _remove_items(self, source_field_name, target_field_name, *objs):
# source_field_name: the PK colname in join table for the source object
# target_field_name: the PK colname in join table for the target object
# *objs - objects to remove
if not objs:
return
# Check that all the objects are of the right type
old_ids = set()
for obj in objs:
if isinstance(obj, self.model):
fk_val = self.target_field.get_foreign_related_value(obj)[0]
old_ids.add(fk_val)
else:
old_ids.add(obj)
db = router.db_for_write(self.through, instance=self.instance)
with transaction.atomic(using=db, savepoint=False):
# Send a signal to the other end if need be.
signals.m2m_changed.send(
sender=self.through, action="pre_remove",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=old_ids, using=db,
)
target_model_qs = super().get_queryset()
if target_model_qs._has_filters():
old_vals = target_model_qs.using(db).filter(**{
'%s__in' % self.target_field.target_field.attname: old_ids})
else:
old_vals = old_ids
filters = self._build_remove_filters(old_vals)
self.through._default_manager.using(db).filter(filters).delete()
signals.m2m_changed.send(
sender=self.through, action="post_remove",
instance=self.instance, reverse=self.reverse,
model=self.model, pk_set=old_ids, using=db,
)
return ManyRelatedManager
|
8fe60ecace3aa2a3fb4fef317e3cf7ff915c39647f84c041a76c60f317c5992b | """
"Rel objects" for related fields.
"Rel objects" (for lack of a better name) carry information about the relation
modeled by a related field and provide some utility functions. They're stored
in the ``remote_field`` attribute of the field.
They also act as reverse fields for the purposes of the Meta API because
they're the closest concept currently available.
"""
from django.core import exceptions
from django.utils.functional import cached_property
from . import BLANK_CHOICE_DASH
from .mixins import FieldCacheMixin
class ForeignObjectRel(FieldCacheMixin):
"""
Used by ForeignObject to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
# Field flags
auto_created = True
concrete = False
editable = False
is_relation = True
# Reverse relations are always nullable (Django can't enforce that a
# foreign key on the related model points to this model).
null = True
def __init__(self, field, to, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, on_delete=None):
self.field = field
self.model = to
self.related_name = related_name
self.related_query_name = related_query_name
self.limit_choices_to = {} if limit_choices_to is None else limit_choices_to
self.parent_link = parent_link
self.on_delete = on_delete
self.symmetrical = False
self.multiple = True
# Some of the following cached_properties can't be initialized in
# __init__ as the field doesn't have its model yet. Calling these methods
# before field.contribute_to_class() has been called will result in
# AttributeError
@cached_property
def hidden(self):
return self.is_hidden()
@cached_property
def name(self):
return self.field.related_query_name()
@property
def remote_field(self):
return self.field
@property
def target_field(self):
"""
When filtering against this relation, return the field on the remote
model against which the filtering should happen.
"""
target_fields = self.get_path_info()[-1].target_fields
if len(target_fields) > 1:
raise exceptions.FieldError("Can't use target_field for multicolumn relations.")
return target_fields[0]
@cached_property
def related_model(self):
if not self.field.model:
raise AttributeError(
"This property can't be accessed before self.field.contribute_to_class has been called.")
return self.field.model
@cached_property
def many_to_many(self):
return self.field.many_to_many
@cached_property
def many_to_one(self):
return self.field.one_to_many
@cached_property
def one_to_many(self):
return self.field.many_to_one
@cached_property
def one_to_one(self):
return self.field.one_to_one
def get_lookup(self, lookup_name):
return self.field.get_lookup(lookup_name)
def get_internal_type(self):
return self.field.get_internal_type()
@property
def db_type(self):
return self.field.db_type
def __repr__(self):
return '<%s: %s.%s>' % (
type(self).__name__,
self.related_model._meta.app_label,
self.related_model._meta.model_name,
)
def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH):
"""
Return choices with a default blank choices included, for use
as <select> choices for this field.
Analog of django.db.models.fields.Field.get_choices(), provided
initially for utilization by RelatedFieldListFilter.
"""
return (blank_choice if include_blank else []) + [
(x.pk, str(x)) for x in self.related_model._default_manager.all()
]
def is_hidden(self):
"""Should the related object be hidden?"""
return bool(self.related_name) and self.related_name[-1] == '+'
def get_joining_columns(self):
return self.field.get_reverse_joining_columns()
def get_extra_restriction(self, where_class, alias, related_alias):
return self.field.get_extra_restriction(where_class, related_alias, alias)
def set_field_name(self):
"""
Set the related field's name, this is not available until later stages
of app loading, so set_field_name is called from
set_attributes_from_rel()
"""
# By default foreign object doesn't relate to any remote field (for
# example custom multicolumn joins currently have no remote field).
self.field_name = None
def get_accessor_name(self, model=None):
# This method encapsulates the logic that decides what name to give an
# accessor descriptor that retrieves related many-to-one or
# many-to-many objects. It uses the lower-cased object_name + "_set",
# but this can be overridden with the "related_name" option.
# Due to backwards compatibility ModelForms need to be able to provide
# an alternate model. See BaseInlineFormSet.get_default_prefix().
opts = model._meta if model else self.related_model._meta
model = model or self.related_model
if self.multiple:
# If this is a symmetrical m2m relation on self, there is no reverse accessor.
if self.symmetrical and model == self.model:
return None
if self.related_name:
return self.related_name
return opts.model_name + ('_set' if self.multiple else '')
def get_path_info(self, filtered_relation=None):
return self.field.get_reverse_path_info(filtered_relation)
def get_cache_name(self):
"""
Return the name of the cache key to use for storing an instance of the
forward model on the reverse model.
"""
return self.get_accessor_name()
class ManyToOneRel(ForeignObjectRel):
"""
Used by the ForeignKey field to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
Note: Because we somewhat abuse the Rel objects by using them as reverse
fields we get the funny situation where
``ManyToOneRel.many_to_one == False`` and
``ManyToOneRel.one_to_many == True``. This is unfortunate but the actual
ManyToOneRel class is a private API and there is work underway to turn
reverse relations into actual fields.
"""
def __init__(self, field, to, field_name, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, on_delete=None):
super().__init__(
field, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
self.field_name = field_name
def __getstate__(self):
state = self.__dict__.copy()
state.pop('related_model', None)
return state
def get_related_field(self):
"""
Return the Field in the 'to' object to which this relationship is tied.
"""
field = self.model._meta.get_field(self.field_name)
if not field.concrete:
raise exceptions.FieldDoesNotExist("No related field named '%s'" % self.field_name)
return field
def set_field_name(self):
self.field_name = self.field_name or self.model._meta.pk.name
class OneToOneRel(ManyToOneRel):
"""
Used by OneToOneField to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
def __init__(self, field, to, field_name, related_name=None, related_query_name=None,
limit_choices_to=None, parent_link=False, on_delete=None):
super().__init__(
field, to, field_name,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
parent_link=parent_link,
on_delete=on_delete,
)
self.multiple = False
class ManyToManyRel(ForeignObjectRel):
"""
Used by ManyToManyField to store information about the relation.
``_meta.get_fields()`` returns this class to provide access to the field
flags for the reverse relation.
"""
def __init__(self, field, to, related_name=None, related_query_name=None,
limit_choices_to=None, symmetrical=True, through=None,
through_fields=None, db_constraint=True):
super().__init__(
field, to,
related_name=related_name,
related_query_name=related_query_name,
limit_choices_to=limit_choices_to,
)
if through and not db_constraint:
raise ValueError("Can't supply a through model and db_constraint=False")
self.through = through
if through_fields and not through:
raise ValueError("Cannot specify through_fields without a through model")
self.through_fields = through_fields
self.symmetrical = symmetrical
self.db_constraint = db_constraint
def get_related_field(self):
"""
Return the field in the 'to' object to which this relationship is tied.
Provided for symmetry with ManyToOneRel.
"""
opts = self.through._meta
if self.through_fields:
field = opts.get_field(self.through_fields[0])
else:
for field in opts.fields:
rel = getattr(field, 'remote_field', None)
if rel and rel.model == self.model:
break
return field.foreign_related_fields[0]
|
ca9660f94d3e4447017324422a8abb8269ab3903bbf5d7828da17d3cf276032e | from django.db.models import Func, IntegerField, Transform, Value, fields
from django.db.models.functions import Coalesce
class BytesToCharFieldConversionMixin:
"""
Convert CharField results from bytes to str.
MySQL returns long data types (bytes) instead of chars when it can't
determine the length of the result string. For example:
LPAD(column1, CHAR_LENGTH(column2), ' ')
returns the LONGTEXT (bytes) instead of VARCHAR.
"""
def convert_value(self, value, expression, connection):
if connection.features.db_functions_convert_bytes_to_str:
if self.output_field.get_internal_type() == 'CharField' and isinstance(value, bytes):
return value.decode()
return super().convert_value(value, expression, connection)
class Chr(Transform):
function = 'CHR'
lookup_name = 'chr'
def as_mysql(self, compiler, connection):
return super().as_sql(
compiler, connection, function='CHAR', template='%(function)s(%(expressions)s USING utf16)'
)
def as_oracle(self, compiler, connection):
return super().as_sql(compiler, connection, template='%(function)s(%(expressions)s USING NCHAR_CS)')
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='CHAR', **extra_context)
class ConcatPair(Func):
"""
Concatenate two arguments together. This is used by `Concat` because not
all backend databases support more than two arguments.
"""
function = 'CONCAT'
def as_sqlite(self, compiler, connection):
coalesced = self.coalesce()
return super(ConcatPair, coalesced).as_sql(
compiler, connection, template='%(expressions)s', arg_joiner=' || '
)
def as_mysql(self, compiler, connection):
# Use CONCAT_WS with an empty separator so that NULLs are ignored.
return super().as_sql(
compiler, connection, function='CONCAT_WS', template="%(function)s('', %(expressions)s)"
)
def coalesce(self):
# null on either side results in null for expression, wrap with coalesce
c = self.copy()
expressions = [
Coalesce(expression, Value('')) for expression in c.get_source_expressions()
]
c.set_source_expressions(expressions)
return c
class Concat(Func):
"""
Concatenate text fields together. Backends that result in an entire
null expression when any arguments are null will wrap each argument in
coalesce functions to ensure a non-null result.
"""
function = None
template = "%(expressions)s"
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Concat must take at least two expressions')
paired = self._paired(expressions)
super().__init__(paired, **extra)
def _paired(self, expressions):
# wrap pairs of expressions in successive concat functions
# exp = [a, b, c, d]
# -> ConcatPair(a, ConcatPair(b, ConcatPair(c, d))))
if len(expressions) == 2:
return ConcatPair(*expressions)
return ConcatPair(expressions[0], self._paired(expressions[1:]))
class Left(Func):
function = 'LEFT'
arity = 2
def __init__(self, expression, length, **extra):
"""
expression: the name of a field, or an expression returning a string
length: the number of characters to return from the start of the string
"""
if not hasattr(length, 'resolve_expression'):
if length < 1:
raise ValueError("'length' must be greater than 0.")
super().__init__(expression, length, **extra)
def get_substr(self):
return Substr(self.source_expressions[0], Value(1), self.source_expressions[1])
def use_substr(self, compiler, connection, **extra_context):
return self.get_substr().as_oracle(compiler, connection, **extra_context)
as_oracle = use_substr
as_sqlite = use_substr
class Length(Transform):
"""Return the number of characters in the expression."""
function = 'LENGTH'
lookup_name = 'length'
output_field = fields.IntegerField()
def as_mysql(self, compiler, connection):
return super().as_sql(compiler, connection, function='CHAR_LENGTH')
class Lower(Transform):
function = 'LOWER'
lookup_name = 'lower'
class LPad(BytesToCharFieldConversionMixin, Func):
function = 'LPAD'
def __init__(self, expression, length, fill_text=Value(' '), **extra):
if not hasattr(length, 'resolve_expression') and length < 0:
raise ValueError("'length' must be greater or equal to 0.")
super().__init__(expression, length, fill_text, **extra)
class LTrim(Transform):
function = 'LTRIM'
lookup_name = 'ltrim'
class Ord(Transform):
function = 'ASCII'
lookup_name = 'ord'
output_field = IntegerField()
def as_mysql(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='ORD', **extra_context)
def as_sqlite(self, compiler, connection, **extra_context):
return super().as_sql(compiler, connection, function='UNICODE', **extra_context)
class Repeat(BytesToCharFieldConversionMixin, Func):
function = 'REPEAT'
def __init__(self, expression, number, **extra):
if not hasattr(number, 'resolve_expression') and number < 0:
raise ValueError("'number' must be greater or equal to 0.")
super().__init__(expression, number, **extra)
def as_oracle(self, compiler, connection, **extra_context):
expression, number = self.source_expressions
rpad = RPad(expression, Length(expression) * number, expression)
return rpad.as_sql(compiler, connection, **extra_context)
class Replace(Func):
function = 'REPLACE'
def __init__(self, expression, text, replacement=Value(''), **extra):
super().__init__(expression, text, replacement, **extra)
class Right(Left):
function = 'RIGHT'
def get_substr(self):
return Substr(self.source_expressions[0], self.source_expressions[1] * Value(-1))
class RPad(LPad):
function = 'RPAD'
class RTrim(Transform):
function = 'RTRIM'
lookup_name = 'rtrim'
class StrIndex(Func):
"""
Return a positive integer corresponding to the 1-indexed position of the
first occurrence of a substring inside another string, or 0 if the
substring is not found.
"""
function = 'INSTR'
arity = 2
output_field = fields.IntegerField()
def as_postgresql(self, compiler, connection):
return super().as_sql(compiler, connection, function='STRPOS')
class Substr(Func):
function = 'SUBSTRING'
def __init__(self, expression, pos, length=None, **extra):
"""
expression: the name of a field, or an expression returning a string
pos: an integer > 0, or an expression returning an integer
length: an optional number of characters to return
"""
if not hasattr(pos, 'resolve_expression'):
if pos < 1:
raise ValueError("'pos' must be greater than 0")
expressions = [expression, pos]
if length is not None:
expressions.append(length)
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection):
return super().as_sql(compiler, connection, function='SUBSTR')
def as_oracle(self, compiler, connection):
return super().as_sql(compiler, connection, function='SUBSTR')
class Trim(Transform):
function = 'TRIM'
lookup_name = 'trim'
class Upper(Transform):
function = 'UPPER'
lookup_name = 'upper'
|
0b0036a1f55b300c581ecd644f8a65ec10c81888304426ab212f069ec86ed5b0 | """Database functions that do comparisons or type conversions."""
from django.db.models import Func
class Cast(Func):
"""Coerce an expression to a new field type."""
function = 'CAST'
template = '%(function)s(%(expressions)s AS %(db_type)s)'
def __init__(self, expression, output_field):
super().__init__(expression, output_field=output_field)
def as_sql(self, compiler, connection, **extra_context):
extra_context['db_type'] = self.output_field.cast_db_type(connection)
return super().as_sql(compiler, connection, **extra_context)
def as_mysql(self, compiler, connection):
# MySQL doesn't support explicit cast to float.
template = '(%(expressions)s + 0.0)' if self.output_field.get_internal_type() == 'FloatField' else None
return self.as_sql(compiler, connection, template=template)
def as_postgresql(self, compiler, connection):
# CAST would be valid too, but the :: shortcut syntax is more readable.
# 'expressions' is wrapped in parentheses in case it's a complex
# expression.
return self.as_sql(compiler, connection, template='(%(expressions)s)::%(db_type)s')
class Coalesce(Func):
"""Return, from left to right, the first non-null expression."""
function = 'COALESCE'
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Coalesce must take at least two expressions')
super().__init__(*expressions, **extra)
def as_oracle(self, compiler, connection):
# Oracle prohibits mixing TextField (NCLOB) and CharField (NVARCHAR2),
# so convert all fields to NCLOB when that type is expected.
if self.output_field.get_internal_type() == 'TextField':
class ToNCLOB(Func):
function = 'TO_NCLOB'
expressions = [
ToNCLOB(expression) for expression in self.get_source_expressions()
]
clone = self.copy()
clone.set_source_expressions(expressions)
return super(Coalesce, clone).as_sql(compiler, connection)
return self.as_sql(compiler, connection)
class Greatest(Func):
"""
Return the maximum expression.
If any expression is null the return value is database-specific:
On PostgreSQL, the maximum not-null expression is returned.
On MySQL, Oracle, and SQLite, if any expression is null, null is returned.
"""
function = 'GREATEST'
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Greatest must take at least two expressions')
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection):
"""Use the MAX function on SQLite."""
return super().as_sqlite(compiler, connection, function='MAX')
class Least(Func):
"""
Return the minimum expression.
If any expression is null the return value is database-specific:
On PostgreSQL, return the minimum not-null expression.
On MySQL, Oracle, and SQLite, if any expression is null, return null.
"""
function = 'LEAST'
def __init__(self, *expressions, **extra):
if len(expressions) < 2:
raise ValueError('Least must take at least two expressions')
super().__init__(*expressions, **extra)
def as_sqlite(self, compiler, connection):
"""Use the MIN function on SQLite."""
return super().as_sqlite(compiler, connection, function='MIN')
|
eeb564bfe603c9c2ebae66aebb0303f2e80f1ad8e61bdcb704fda8366fde35a4 | from .comparison import Cast, Coalesce, Greatest, Least
from .datetime import (
Extract, ExtractDay, ExtractHour, ExtractMinute, ExtractMonth,
ExtractQuarter, ExtractSecond, ExtractWeek, ExtractWeekDay, ExtractYear,
Now, Trunc, TruncDate, TruncDay, TruncHour, TruncMinute, TruncMonth,
TruncQuarter, TruncSecond, TruncTime, TruncWeek, TruncYear,
)
from .text import (
Chr, Concat, ConcatPair, Left, Length, Lower, LPad, LTrim, Ord, Repeat,
Replace, Right, RPad, RTrim, StrIndex, Substr, Trim, Upper,
)
from .window import (
CumeDist, DenseRank, FirstValue, Lag, LastValue, Lead, NthValue, Ntile,
PercentRank, Rank, RowNumber,
)
__all__ = [
# comparison and conversion
'Cast', 'Coalesce', 'Greatest', 'Least',
# datetime
'Extract', 'ExtractDay', 'ExtractHour', 'ExtractMinute', 'ExtractMonth',
'ExtractQuarter', 'ExtractSecond', 'ExtractWeek', 'ExtractWeekDay',
'ExtractYear', 'Now', 'Trunc', 'TruncDate', 'TruncDay', 'TruncHour',
'TruncMinute', 'TruncMonth', 'TruncQuarter', 'TruncSecond', 'TruncTime',
'TruncWeek', 'TruncYear',
# text
'Chr', 'Concat', 'ConcatPair', 'Left', 'Length', 'Lower', 'LPad', 'LTrim',
'Ord', 'Repeat', 'Replace', 'Right', 'RPad', 'RTrim', 'StrIndex', 'Substr',
'Trim', 'Upper',
# window
'CumeDist', 'DenseRank', 'FirstValue', 'Lag', 'LastValue', 'Lead',
'NthValue', 'Ntile', 'PercentRank', 'Rank', 'RowNumber',
]
|
Subsets and Splits
No saved queries yet
Save your SQL queries to embed, download, and access them later. Queries will appear here once saved.