text: """
  The Request class is used as a wrapper around the standard request object.
  
  The wrapped request then offers a richer API, in particular :
  
      - content automatically parsed according to `Content-Type` header,
        and available as `request.data`
      - full support of PUT method, including support for file uploads
      - form overloading of HTTP method, content type and content
  """
  from __future__ import unicode_literals
  
  import sys
  import warnings
  
  from django.conf import settings
  from django.http import QueryDict
  from django.http.multipartparser import parse_header
  from django.utils import six
  from django.utils.datastructures import MultiValueDict
  
  from rest_framework import HTTP_HEADER_ENCODING, exceptions
  from rest_framework.settings import api_settings
  
  
  def is_form_media_type(media_type):
      """
      Return True if the media type is a valid form media type.
      """
      base_media_type, params = parse_header(media_type.encode(HTTP_HEADER_ENCODING))
      return (base_media_type == 'application/x-www-form-urlencoded' or
              base_media_type == 'multipart/form-data')
  
  
  class override_method(object):
      """
      A context manager that temporarily overrides the method on a request,
      additionally setting the `view.request` attribute.
  
      Usage:
  
          with override_method(view, request, 'POST') as request:
              ... # Do stuff with `view` and `request`
      """
      def __init__(self, view, request, method):
          self.view = view
          self.request = request
          self.method = method
          self.action = getattr(view, 'action', None)
  
      def __enter__(self):
          self.view.request = clone_request(self.request, self.method)
          # For viewsets we also set the `.action` attribute.
          action_map = getattr(self.view, 'action_map', {})
          self.view.action = action_map.get(self.method.lower())
          return self.view.request
  
      def __exit__(self, *args, **kwarg):
          self.view.request = self.request
          self.view.action = self.action
  
  
  class Empty(object):
      """
      Placeholder for unset attributes.
      Cannot use `None`, as that may be a valid value.
      """
      pass
  
  
  def _hasattr(obj, name):
      return not getattr(obj, name) is Empty
  
  
  def clone_request(request, method):
      """
      Internal helper method to clone a request, replacing with a different
      HTTP method.  Used for checking permissions against other methods.
      """
      ret = Request(request=request._request,
                    parsers=request.parsers,
                    authenticators=request.authenticators,
                    negotiator=request.negotiator,
                    parser_context=request.parser_context)
      ret._data = request._data
      ret._files = request._files
      ret._full_data = request._full_data
      ret._content_type = request._content_type
      ret._stream = request._stream
      ret._method = method
      if hasattr(request, '_user'):
          ret._user = request._user
      if hasattr(request, '_auth'):
          ret._auth = request._auth
      if hasattr(request, '_authenticator'):
          ret._authenticator = request._authenticator
      if hasattr(request, 'accepted_renderer'):
          ret.accepted_renderer = request.accepted_renderer
      if hasattr(request, 'accepted_media_type'):
          ret.accepted_media_type = request.accepted_media_type
      if hasattr(request, 'version'):
          ret.version = request.version
      if hasattr(request, 'versioning_scheme'):
          ret.versioning_scheme = request.versioning_scheme
      return ret
  
  
  class ForcedAuthentication(object):
      """
      This authentication class is used if the test client or request factory
      forcibly authenticated the request.
      """
  
      def __init__(self, force_user, force_token):
          self.force_user = force_user
          self.force_token = force_token
  
      def authenticate(self, request):
          return (self.force_user, self.force_token)
  
  
  class Request(object):
      """
      Wrapper allowing to enhance a standard `HttpRequest` instance.
  
      Kwargs:
          - request(HttpRequest). The original request instance.
          - parsers_classes(list/tuple). The parsers to use for parsing the
            request content.
          - authentication_classes(list/tuple). The authentications used to try
            authenticating the request's user.
      """
  
      _METHOD_PARAM = api_settings.FORM_METHOD_OVERRIDE
      _CONTENT_PARAM = api_settings.FORM_CONTENT_OVERRIDE
      _CONTENTTYPE_PARAM = api_settings.FORM_CONTENTTYPE_OVERRIDE
  
      def __init__(self, request, parsers=None, authenticators=None,
                   negotiator=None, parser_context=None):
          self._request = request
          self.parsers = parsers or ()
          self.authenticators = authenticators or ()
          self.negotiator = negotiator or self._default_negotiator()
          self.parser_context = parser_context
          self._data = Empty
          self._files = Empty
          self._full_data = Empty
          self._method = Empty
          self._content_type = Empty
          self._stream = Empty
  
          if self.parser_context is None:
              self.parser_context = {}
          self.parser_context['request'] = self
          self.parser_context['encoding'] = request.encoding or settings.DEFAULT_CHARSET
  
          force_user = getattr(request, '_force_auth_user', None)
          force_token = getattr(request, '_force_auth_token', None)
          if (force_user is not None or force_token is not None):
              forced_auth = ForcedAuthentication(force_user, force_token)
              self.authenticators = (forced_auth,)
  
      def _default_negotiator(self):
          return api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS()
  
      @property
      def method(self):
          """
          Returns the HTTP method.
  
          This allows the `method` to be overridden by using a hidden `form`
          field on a form POST request.
          """
          if not _hasattr(self, '_method'):
              self._load_method_and_content_type()
          return self._method
  
      @property
      def content_type(self):
          """
          Returns the content type header.
  
          This should be used instead of `request.META.get('HTTP_CONTENT_TYPE')`,
          as it allows the content type to be overridden by using a hidden form
          field on a form POST request.
          """
          if not _hasattr(self, '_content_type'):
              self._load_method_and_content_type()
          return self._content_type
  
      @property
      def stream(self):
          """
          Returns an object that may be used to stream the request content.
          """
          if not _hasattr(self, '_stream'):
              self._load_stream()
          return self._stream
  
      @property
      def query_params(self):
          """
          More semantically correct name for request.GET.
          """
          return self._request.GET
  
      @property
      def QUERY_PARAMS(self):
          """
          Synonym for `.query_params`, for backwards compatibility.
          """
          warnings.warn(
              "`request.QUERY_PARAMS` is deprecated. Use `request.query_params` instead.",
              DeprecationWarning,
              stacklevel=1
          )
          return self._request.GET
  
      @property
      def data(self):
          if not _hasattr(self, '_full_data'):
              self._load_data_and_files()
          return self._full_data
  
      @property
      def DATA(self):
          """
          Parses the request body and returns the data.
  
          Similar to usual behaviour of `request.POST`, except that it handles
          arbitrary parsers, and also works on methods other than POST (eg PUT).
          """
          warnings.warn(
              "`request.DATA` is deprecated. Use `request.data` instead.",
              DeprecationWarning,
              stacklevel=1
          )
          if not _hasattr(self, '_data'):
              self._load_data_and_files()
          return self._data
  
      @property
      def FILES(self):
          """
          Parses the request body and returns any files uploaded in the request.
  
          Similar to usual behaviour of `request.FILES`, except that it handles
          arbitrary parsers, and also works on methods other than POST (eg PUT).
          """
          warnings.warn(
              "`request.FILES` is deprecated. Use `request.data` instead.",
              DeprecationWarning,
              stacklevel=1
          )
          if not _hasattr(self, '_files'):
              self._load_data_and_files()
          return self._files
  
      @property
      def user(self):
          """
          Returns the user associated with the current request, as authenticated
          by the authentication classes provided to the request.
          """
          if not hasattr(self, '_user'):
              self._authenticate()
          return self._user
  
      @user.setter
      def user(self, value):
          """
          Sets the user on the current request. This is necessary to maintain
          compatibility with django.contrib.auth where the user property is
          set in the login and logout functions.
  
          Note that we also set the user on Django's underlying `HttpRequest`
          instance, ensuring that it is available to any middleware in the stack.
          """
          self._user = value
          self._request.user = value
  
      @property
      def auth(self):
          """
          Returns any non-user authentication information associated with the
          request, such as an authentication token.
          """
          if not hasattr(self, '_auth'):
              self._authenticate()
          return self._auth
  
      @auth.setter
      def auth(self, value):
          """
          Sets any non-user authentication information associated with the
          request, such as an authentication token.
          """
          self._auth = value
          self._request.auth = value
  
      @property
      def successful_authenticator(self):
          """
          Return the instance of the authentication instance class that was used
          to authenticate the request, or `None`.
          """
          if not hasattr(self, '_authenticator'):
              self._authenticate()
          return self._authenticator
  
      def _load_data_and_files(self):
          """
          Parses the request content into `self.data`.
          """
          if not _hasattr(self, '_content_type'):
              self._load_method_and_content_type()
  
          if not _hasattr(self, '_data'):
              self._data, self._files = self._parse()
              if self._files:
                  self._full_data = self._data.copy()
                  self._full_data.update(self._files)
              else:
                  self._full_data = self._data
  
      def _load_method_and_content_type(self):
          """
          Sets the method and content_type, and then check if they've
          been overridden.
          """
          self._content_type = self.META.get('HTTP_CONTENT_TYPE',
                                             self.META.get('CONTENT_TYPE', ''))
  
          self._perform_form_overloading()
  
          if not _hasattr(self, '_method'):
              self._method = self._request.method
  
              # Allow X-HTTP-METHOD-OVERRIDE header
              if 'HTTP_X_HTTP_METHOD_OVERRIDE' in self.META:
                  self._method = self.META['HTTP_X_HTTP_METHOD_OVERRIDE'].upper()
  
      def _load_stream(self):
          """
          Return the content body of the request, as a stream.
          """
          try:
              content_length = int(
                  self.META.get(
                      'CONTENT_LENGTH', self.META.get('HTTP_CONTENT_LENGTH')
                  )
              )
          except (ValueError, TypeError):
              content_length = 0
  
          if content_length == 0:
              self._stream = None
          elif hasattr(self._request, 'read'):
              self._stream = self._request
          else:
              self._stream = six.BytesIO(self.raw_post_data)
  
      def _perform_form_overloading(self):
          """
          If this is a form POST request, then we need to check if the method and
          content/content_type have been overridden by setting them in hidden
          form fields or not.
          """
  
          USE_FORM_OVERLOADING = (
              self._METHOD_PARAM or
              (self._CONTENT_PARAM and self._CONTENTTYPE_PARAM)
          )
  
          # We only need to use form overloading on form POST requests.
          if (
              self._request.method != 'POST' or
              not USE_FORM_OVERLOADING or
              not is_form_media_type(self._content_type)
          ):
              return
  
          # At this point we're committed to parsing the request as form data.
          self._data = self._request.POST
          self._files = self._request.FILES
          self._full_data = self._data.copy()
          self._full_data.update(self._files)
  
          # Method overloading - change the method and remove the param from the content.
          if (
              self._METHOD_PARAM and
              self._METHOD_PARAM in self._data
          ):
              self._method = self._data[self._METHOD_PARAM].upper()
  
          # Content overloading - modify the content type, and force re-parse.
          if (
              self._CONTENT_PARAM and
              self._CONTENTTYPE_PARAM and
              self._CONTENT_PARAM in self._data and
              self._CONTENTTYPE_PARAM in self._data
          ):
              self._content_type = self._data[self._CONTENTTYPE_PARAM]
              self._stream = six.BytesIO(self._data[self._CONTENT_PARAM].encode(self.parser_context['encoding']))
              self._data, self._files, self._full_data = (Empty, Empty, Empty)
  
      def _parse(self):
          """
          Parse the request content, returning a two-tuple of (data, files)
  
          May raise an `UnsupportedMediaType`, or `ParseError` exception.
          """
          stream = self.stream
          media_type = self.content_type
  
          if stream is None or media_type is None:
              empty_data = QueryDict('', encoding=self._request._encoding)
              empty_files = MultiValueDict()
              return (empty_data, empty_files)
  
          parser = self.negotiator.select_parser(self, self.parsers)
  
          if not parser:
              raise exceptions.UnsupportedMediaType(media_type)
  
          try:
              parsed = parser.parse(stream, media_type, self.parser_context)
          except:
              # If we get an exception during parsing, fill in empty data and
              # re-raise.  Ensures we don't simply repeat the error when
              # attempting to render the browsable renderer response, or when
              # logging the request or similar.
              self._data = QueryDict('', encoding=self._request._encoding)
              self._files = MultiValueDict()
              self._full_data = self._data
              raise
  
          # Parser classes may return the raw data, or a
          # DataAndFiles object.  Unpack the result as required.
          try:
              return (parsed.data, parsed.files)
          except AttributeError:
              empty_files = MultiValueDict()
              return (parsed, empty_files)
  
      def _authenticate(self):
          """
          Attempt to authenticate the request using each authentication instance
          in turn.
          Returns a three-tuple of (authenticator, user, authtoken).
          """
          for authenticator in self.authenticators:
              try:
                  user_auth_tuple = authenticator.authenticate(self)
              except exceptions.APIException:
                  self._not_authenticated()
                  raise
  
              if user_auth_tuple is not None:
                  self._authenticator = authenticator
                  self.user, self.auth = user_auth_tuple
                  return
  
          self._not_authenticated()
  
      def _not_authenticated(self):
          """
          Return a three-tuple of (authenticator, user, authtoken), representing
          an unauthenticated request.
  
          By default this will be (None, AnonymousUser, None).
          """
          self._authenticator = None
  
          if api_settings.UNAUTHENTICATED_USER:
              self.user = api_settings.UNAUTHENTICATED_USER()
          else:
              self.user = None
  
          if api_settings.UNAUTHENTICATED_TOKEN:
              self.auth = api_settings.UNAUTHENTICATED_TOKEN()
          else:
              self.auth = None
  
      def __getattribute__(self, attr):
          """
          If an attribute does not exist on this instance, then we also attempt
          to proxy it to the underlying HttpRequest object.
          """
          try:
              return super(Request, self).__getattribute__(attr)
          except AttributeError:
              info = sys.exc_info()
              try:
                  return getattr(self._request, attr)
              except AttributeError:
                  six.reraise(info[0], info[1], info[2].tb_next)
  