text: # -*- coding: utf-8 -*-
  
  ##############################################################################
  #
  #    OpenERP, Open Source Business Applications
  #    Copyright (C) 2004-2012 OpenERP S.A. (<http://openerp.com>).
  #
  #    This program is free software: you can redistribute it and/or modify
  #    it under the terms of the GNU Affero General Public License as
  #    published by the Free Software Foundation, either version 3 of the
  #    License, or (at your option) any later version.
  #
  #    This program is distributed in the hope that it will be useful,
  #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  #    GNU Affero General Public License for more details.
  #
  #    You should have received a copy of the GNU Affero General Public License
  #    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  #
  ##############################################################################
  import logging
  import re
  import time
  import types
  
  import openerp
  import openerp.modules.registry
  from openerp import SUPERUSER_ID
  from openerp import netsvc, pooler, tools
  from openerp.osv import fields,osv
  from openerp.osv.orm import Model
  from openerp.tools.safe_eval import safe_eval as eval
  from openerp.tools import config
  from openerp.tools.translate import _
  from openerp.osv.orm import except_orm, browse_record, MAGIC_COLUMNS
  
  _logger = logging.getLogger(__name__)
  
  MODULE_UNINSTALL_FLAG = '_force_unlink'
  
  def _get_fields_type(self, cr, uid, context=None):
      # Avoid too many nested `if`s below, as RedHat's Python 2.6
      # break on it. See bug 939653.
      return sorted([(k,k) for k,v in fields.__dict__.iteritems()
                        if type(v) == types.TypeType and \
                           issubclass(v, fields._column) and \
                           v != fields._column and \
                           not v._deprecated and \
                           not issubclass(v, fields.function)])
  
  def _in_modules(self, cr, uid, ids, field_name, arg, context=None):
      #pseudo-method used by fields.function in ir.model/ir.model.fields
      module_pool = self.pool.get("ir.module.module")
      installed_module_ids = module_pool.search(cr, uid, [('state','=','installed')])
      installed_module_names = module_pool.read(cr, uid, installed_module_ids, ['name'], context=context)
      installed_modules = set(x['name'] for x in installed_module_names)
  
      result = {}
      xml_ids = osv.osv._get_xml_ids(self, cr, uid, ids)
      for k,v in xml_ids.iteritems():
          result[k] = ', '.join(sorted(installed_modules & set(xml_id.split('.')[0] for xml_id in v)))
      return result
  
  class ir_model(osv.osv):
      _name = 'ir.model'
      _description = "Models"
      _order = 'model'
  
      def _is_osv_memory(self, cr, uid, ids, field_name, arg, context=None):
          models = self.browse(cr, uid, ids, context=context)
          res = dict.fromkeys(ids)
          for model in models:
              if self.pool.get(model.model):
                  res[model.id] = self.pool.get(model.model).is_transient()
              else:
                  _logger.error('Missing model %s' % (model.model, ))
          return res
  
      def _search_osv_memory(self, cr, uid, model, name, domain, context=None):
          if not domain:
              return []
          __, operator, value = domain[0]
          if operator not in ['=', '!=']:
              raise osv.except_osv(_("Invalid Search Criteria"), _('The osv_memory field can only be compared with = and != operator.'))
          value = bool(value) if operator == '=' else not bool(value)
          all_model_ids = self.search(cr, uid, [], context=context)
          is_osv_mem = self._is_osv_memory(cr, uid, all_model_ids, 'osv_memory', arg=None, context=context)
          return [('id', 'in', [id for id in is_osv_mem if bool(is_osv_mem[id]) == value])]
  
      def _view_ids(self, cr, uid, ids, field_name, arg, context=None):
          models = self.browse(cr, uid, ids)
          res = {}
          for model in models:
              res[model.id] = self.pool.get("ir.ui.view").search(cr, uid, [('model', '=', model.model)])
          return res
  
      _columns = {
          'name': fields.char('Model Description', size=64, translate=True, required=True),
          'model': fields.char('Model', size=64, required=True, select=1),
          'info': fields.text('Information'),
          'field_id': fields.one2many('ir.model.fields', 'model_id', 'Fields', required=True),
          'state': fields.selection([('manual','Custom Object'),('base','Base Object')],'Type',readonly=True),
          'access_ids': fields.one2many('ir.model.access', 'model_id', 'Access'),
          'osv_memory': fields.function(_is_osv_memory, string='Transient Model', type='boolean',
              fnct_search=_search_osv_memory,
              help="This field specifies whether the model is transient or not (i.e. if records are automatically deleted from the database or not)"),
          'modules': fields.function(_in_modules, type='char', size=128, string='In Modules', help='List of modules in which the object is defined or inherited'),
          'view_ids': fields.function(_view_ids, type='one2many', obj='ir.ui.view', string='Views'),
      }
  
      _defaults = {
          'model': 'x_',
          'state': lambda self,cr,uid,ctx=None: (ctx and ctx.get('manual',False)) and 'manual' or 'base',
      }
  
      def _check_model_name(self, cr, uid, ids, context=None):
          for model in self.browse(cr, uid, ids, context=context):
              if model.state=='manual':
                  if not model.model.startswith('x_'):
                      return False
              if not re.match('^[a-z_A-Z0-9.]+$',model.model):
                  return False
          return True
  
      def _model_name_msg(self, cr, uid, ids, context=None):
          return _('The Object name must start with x_ and not contain any special character !')
  
      _constraints = [
          (_check_model_name, _model_name_msg, ['model']),
      ]
      _sql_constraints = [
          ('obj_name_uniq', 'unique (model)', 'Each model must be unique!'),
      ]
  
      # overridden to allow searching both on model name (model field)
      # and model description (name field)
      def _name_search(self, cr, uid, name='', args=None, operator='ilike', context=None, limit=100, name_get_uid=None):
          if args is None:
              args = []
          domain = args + ['|', ('model', operator, name), ('name', operator, name)]
          return self.name_get(cr, name_get_uid or uid,
                               super(ir_model, self).search(cr, uid, domain, limit=limit, context=context),
                               context=context)
  
      def _drop_table(self, cr, uid, ids, context=None):
          for model in self.browse(cr, uid, ids, context):
              model_pool = self.pool.get(model.model)
              cr.execute('select relkind from pg_class where relname=%s', (model_pool._table,))
              result = cr.fetchone()
              if result and result[0] == 'v':
                  cr.execute('DROP view %s' % (model_pool._table,))
              elif result and result[0] == 'r':
                  cr.execute('DROP TABLE %s' % (model_pool._table,))
          return True
  
      def unlink(self, cr, user, ids, context=None):
          # Prevent manual deletion of module tables
          if context is None: context = {}
          if isinstance(ids, (int, long)):
              ids = [ids]
          if not context.get(MODULE_UNINSTALL_FLAG):
              for model in self.browse(cr, user, ids, context):
                  if model.state != 'manual':
                      raise except_orm(_('Error'), _("Model '%s' contains module data and cannot be removed!") % (model.name,))
  
          self._drop_table(cr, user, ids, context)
          res = super(ir_model, self).unlink(cr, user, ids, context)
          if not context.get(MODULE_UNINSTALL_FLAG):
              # only reload pool for normal unlink. For module uninstall the
              # reload is done independently in openerp.modules.loading
              cr.commit() # must be committed before reloading registry in new cursor
              pooler.restart_pool(cr.dbname)
              openerp.modules.registry.RegistryManager.signal_registry_change(cr.dbname)
  
          return res
  
      def write(self, cr, user, ids, vals, context=None):
          if context:
              context.pop('__last_update', None)
          # Filter out operations 4 link from field id, because openerp-web
          # always write (4,id,False) even for non dirty items
          if 'field_id' in vals:
              vals['field_id'] = [op for op in vals['field_id'] if op[0] != 4]
          return super(ir_model,self).write(cr, user, ids, vals, context)
  
      def create(self, cr, user, vals, context=None):
          if  context is None:
              context = {}
          if context and context.get('manual'):
              vals['state']='manual'
          res = super(ir_model,self).create(cr, user, vals, context)
          if vals.get('state','base')=='manual':
              self.instanciate(cr, user, vals['model'], context)
              ctx = dict(context,
                  field_name=vals['name'],
                  field_state='manual',
                  select=vals.get('select_level', '0'),
                  update_custom_fields=True)
              self.pool.get(vals['model'])._auto_init(cr, ctx)
              self.pool.get(vals['model'])._auto_end(cr, ctx) # actually create FKs!
              openerp.modules.registry.RegistryManager.signal_registry_change(cr.dbname)
          return res
  
      def instanciate(self, cr, user, model, context=None):
          class x_custom_model(osv.osv):
              _custom = True
          x_custom_model._name = model
          x_custom_model._module = False
          a = x_custom_model.create_instance(self.pool, cr)
          if not a._columns:
              x_name = 'id'
          elif 'x_name' in a._columns.keys():
              x_name = 'x_name'
          else:
              x_name = a._columns.keys()[0]
          x_custom_model._rec_name = x_name
          a._rec_name = x_name
  
  class ir_model_fields(osv.osv):
      _name = 'ir.model.fields'
      _description = "Fields"
  
      _columns = {
          'name': fields.char('Name', required=True, size=64, select=1),
          'model': fields.char('Object Name', size=64, required=True, select=1,
              help="The technical name of the model this field belongs to"),
          'relation': fields.char('Object Relation', size=64,
              help="For relationship fields, the technical name of the target model"),
          'relation_field': fields.char('Relation Field', size=64,
              help="For one2many fields, the field on the target model that implement the opposite many2one relationship"),
          'model_id': fields.many2one('ir.model', 'Model', required=True, select=True, ondelete='cascade',
              help="The model this field belongs to"),
          'field_description': fields.char('Field Label', required=True, size=256),
          'ttype': fields.selection(_get_fields_type, 'Field Type',size=64, required=True),
          'selection': fields.char('Selection Options',size=128, help="List of options for a selection field, "
              "specified as a Python expression defining a list of (key, label) pairs. "
              "For example: [('blue','Blue'),('yellow','Yellow')]"),
          'required': fields.boolean('Required'),
          'readonly': fields.boolean('Readonly'),
          'select_level': fields.selection([('0','Not Searchable'),('1','Always Searchable'),('2','Advanced Search (deprecated)')],'Searchable', required=True),
          'translate': fields.boolean('Translatable', help="Whether values for this field can be translated (enables the translation mechanism for that field)"),
          'size': fields.integer('Size'),
          'state': fields.selection([('manual','Custom Field'),('base','Base Field')],'Type', required=True, readonly=True, select=1),
          'on_delete': fields.selection([('cascade','Cascade'),('set null','Set NULL')], 'On Delete', help='On delete property for many2one fields'),
          'domain': fields.char('Domain', size=256, help="The optional domain to restrict possible values for relationship fields, "
              "specified as a Python expression defining a list of triplets. "
              "For example: [('color','=','red')]"),
          'groups': fields.many2many('res.groups', 'ir_model_fields_group_rel', 'field_id', 'group_id', 'Groups'),
          'view_load': fields.boolean('View Auto-Load'),
          'selectable': fields.boolean('Selectable'),
          'modules': fields.function(_in_modules, type='char', size=128, string='In Modules', help='List of modules in which the field is defined'),
          'serialization_field_id': fields.many2one('ir.model.fields', 'Serialization Field', domain = "[('ttype','=','serialized')]",
                                                    ondelete='cascade', help="If set, this field will be stored in the sparse "
                                                                             "structure of the serialization field, instead "
                                                                             "of having its own database column. This cannot be "
                                                                             "changed after creation."),
      }
      _rec_name='field_description'
      _defaults = {
          'view_load': 0,
          'selection': "",
          'domain': "[]",
          'name': 'x_',
          'state': lambda self,cr,uid,ctx=None: (ctx and ctx.get('manual',False)) and 'manual' or 'base',
          'on_delete': 'set null',
          'select_level': '0',
          'field_description': '',
          'selectable': 1,
      }
      _order = "name"
  
      def _check_selection(self, cr, uid, selection, context=None):
          try:
              selection_list = eval(selection)
          except Exception:
              _logger.warning('Invalid selection list definition for fields.selection', exc_info=True)
              raise except_orm(_('Error'),
                      _("The Selection Options expression is not a valid Pythonic expression."
                        "Please provide an expression in the [('key','Label'), ...] format."))
  
          check = True
          if not (isinstance(selection_list, list) and selection_list):
              check = False
          else:
              for item in selection_list:
                  if not (isinstance(item, (tuple,list)) and len(item) == 2):
                      check = False
                      break
  
          if not check:
                  raise except_orm(_('Error'),
                      _("The Selection Options expression is must be in the [('key','Label'), ...] format!"))
          return True
  
      def _size_gt_zero_msg(self, cr, user, ids, context=None):
          return _('Size of the field can never be less than 0 !')
  
      _sql_constraints = [
          ('size_gt_zero', 'CHECK (size>=0)',_size_gt_zero_msg ),
      ]
  
      def _drop_column(self, cr, uid, ids, context=None):
          for field in self.browse(cr, uid, ids, context):
              if field.name in MAGIC_COLUMNS:
                  continue
              model = self.pool.get(field.model)
              cr.execute('select relkind from pg_class where relname=%s', (model._table,))
              result = cr.fetchone()
              cr.execute("SELECT column_name FROM information_schema.columns WHERE table_name ='%s' and column_name='%s'" %(model._table, field.name))
              column_name = cr.fetchone()
              if column_name and (result and result[0] == 'r'):
                  cr.execute('ALTER table "%s" DROP column "%s" cascade' % (model._table, field.name))
              model._columns.pop(field.name, None)
          return True
  
      def unlink(self, cr, user, ids, context=None):
          # Prevent manual deletion of module columns
          if context is None: context = {}
          if isinstance(ids, (int, long)):
              ids = [ids]
          if not context.get(MODULE_UNINSTALL_FLAG) and \
                  any(field.state != 'manual' for field in self.browse(cr, user, ids, context)):
              raise except_orm(_('Error'), _("This column contains module data and cannot be removed!"))
  
          self._drop_column(cr, user, ids, context)
          res = super(ir_model_fields, self).unlink(cr, user, ids, context)
          if not context.get(MODULE_UNINSTALL_FLAG):
              cr.commit()
              openerp.modules.registry.RegistryManager.signal_registry_change(cr.dbname)
          return res
  
      def create(self, cr, user, vals, context=None):
          if 'model_id' in vals:
              model_data = self.pool.get('ir.model').browse(cr, user, vals['model_id'])
              vals['model'] = model_data.model
          if context is None:
              context = {}
          if context and context.get('manual',False):
              vals['state'] = 'manual'
          if vals.get('ttype', False) == 'selection':
              if not vals.get('selection',False):
                  raise except_orm(_('Error'), _('For selection fields, the Selection Options must be given!'))
              self._check_selection(cr, user, vals['selection'], context=context)
          res = super(ir_model_fields,self).create(cr, user, vals, context)
          if vals.get('state','base') == 'manual':
              if not vals['name'].startswith('x_'):
                  raise except_orm(_('Error'), _("Custom fields must have a name that starts with 'x_' !"))
  
              if vals.get('relation',False) and not self.pool.get('ir.model').search(cr, user, [('model','=',vals['relation'])]):
                  raise except_orm(_('Error'), _("Model %s does not exist!") % vals['relation'])
  
              if self.pool.get(vals['model']):
                  if vals['model'].startswith('x_') and vals['name'] == 'x_name':
                      self.pool[vals['model']]._rec_name = 'x_name'
                  self.pool.get(vals['model']).__init__(self.pool, cr)
                  #Added context to _auto_init for special treatment to custom field for select_level
                  ctx = dict(context,
                      field_name=vals['name'],
                      field_state='manual',
                      select=vals.get('select_level', '0'),
                      update_custom_fields=True)
                  self.pool.get(vals['model'])._auto_init(cr, ctx)
                  self.pool.get(vals['model'])._auto_end(cr, ctx) # actually create FKs!
                  openerp.modules.registry.RegistryManager.signal_registry_change(cr.dbname)
  
          return res
  
      def write(self, cr, user, ids, vals, context=None):
          if context is None:
              context = {}
          if context and context.get('manual',False):
              vals['state'] = 'manual'
  
          #For the moment renaming a sparse field or changing the storing system is not allowed. This may be done later
          if 'serialization_field_id' in vals or 'name' in vals:
              for field in self.browse(cr, user, ids, context=context):
                  if 'serialization_field_id' in vals and field.serialization_field_id.id != vals['serialization_field_id']:
                      raise except_orm(_('Error!'),  _('Changing the storing system for field "%s" is not allowed.')%field.name)
                  if field.serialization_field_id and (field.name != vals['name']):
                      raise except_orm(_('Error!'),  _('Renaming sparse field "%s" is not allowed')%field.name)
  
          column_rename = None # if set, *one* column can be renamed here
          obj = None
          models_patch = {}    # structs of (obj, [(field, prop, change_to),..])
                               # data to be updated on the orm model
  
          # static table of properties
          model_props = [ # (our-name, fields.prop, set_fn)
              ('field_description', 'string', tools.ustr),
              ('required', 'required', bool),
              ('readonly', 'readonly', bool),
              ('domain', '_domain', eval),
              ('size', 'size', int),
              ('on_delete', 'ondelete', str),
              ('translate', 'translate', bool),
              ('view_load', 'view_load', bool),
              ('selectable', 'selectable', bool),
              ('select_level', 'select', int),
              ('selection', 'selection', eval),
              ]
  
          if vals and ids:
              checked_selection = False # need only check it once, so defer
  
              for item in self.browse(cr, user, ids, context=context):
                  if not (obj and obj._name == item.model):
                      obj = self.pool.get(item.model)
  
                  if item.state != 'manual':
                      raise except_orm(_('Error!'),
                          _('Properties of base fields cannot be altered in this manner! '
                            'Please modify them through Python code, '
                            'preferably through a custom addon!'))
  
                  if item.ttype == 'selection' and 'selection' in vals \
                          and not checked_selection:
                      self._check_selection(cr, user, vals['selection'], context=context)
                      checked_selection = True
  
                  final_name = item.name
                  if 'name' in vals and vals['name'] != item.name:
                      # We need to rename the column
                      if column_rename:
                          raise except_orm(_('Error!'), _('Can only rename one column at a time!'))
                      if vals['name'] in obj._columns:
                          raise except_orm(_('Error!'), _('Cannot rename column to %s, because that column already exists!') % vals['name'])
                      if vals.get('state', 'base') == 'manual' and not vals['name'].startswith('x_'):
                          raise except_orm(_('Error!'), _('New column name must still start with x_ , because it is a custom field!'))
                      if '\'' in vals['name'] or '"' in vals['name'] or ';' in vals['name']:
                          raise ValueError('Invalid character in column name')
                      column_rename = (obj, (obj._table, item.name, vals['name']))
                      final_name = vals['name']
  
                  if 'model_id' in vals and vals['model_id'] != item.model_id:
                      raise except_orm(_("Error!"), _("Changing the model of a field is forbidden!"))
  
                  if 'ttype' in vals and vals['ttype'] != item.ttype:
                      raise except_orm(_("Error!"), _("Changing the type of a column is not yet supported. "
                                  "Please drop it and create it again!"))
  
                  # We don't check the 'state', because it might come from the context
                  # (thus be set for multiple fields) and will be ignored anyway.
                  if obj:
                      models_patch.setdefault(obj._name, (obj,[]))
                      # find out which properties (per model) we need to update
                      for field_name, field_property, set_fn in model_props:
                          if field_name in vals:
                              property_value = set_fn(vals[field_name])
                              if getattr(obj._columns[item.name], field_property) != property_value:
                                  models_patch[obj._name][1].append((final_name, field_property, property_value))
                          # our dict is ready here, but no properties are changed so far
  
          # These shall never be written (modified)
          for column_name in ('model_id', 'model', 'state'):
              if column_name in vals:
                  del vals[column_name]
  
          res = super(ir_model_fields,self).write(cr, user, ids, vals, context=context)
  
          if column_rename:
              cr.execute('ALTER TABLE "%s" RENAME COLUMN "%s" TO "%s"' % column_rename[1])
              # This is VERY risky, but let us have this feature:
              # we want to change the key of column in obj._columns dict
              col = column_rename[0]._columns.pop(column_rename[1][1]) # take object out, w/o copy
              column_rename[0]._columns[column_rename[1][2]] = col
  
          if models_patch:
              # We have to update _columns of the model(s) and then call their
              # _auto_init to sync the db with the model. Hopefully, since write()
              # was called earlier, they will be in-sync before the _auto_init.
              # Anything we don't update in _columns now will be reset from
              # the model into ir.model.fields (db).
              ctx = dict(context, select=vals.get('select_level', '0'),
                         update_custom_fields=True)
  
              for __, patch_struct in models_patch.items():
                  obj = patch_struct[0]
                  for col_name, col_prop, val in patch_struct[1]:
                      setattr(obj._columns[col_name], col_prop, val)
                  obj._auto_init(cr, ctx)
                  obj._auto_end(cr, ctx) # actually create FKs!
              openerp.modules.registry.RegistryManager.signal_registry_change(cr.dbname)
          return res
  
  class ir_model_constraint(Model):
      """
      This model tracks PostgreSQL foreign keys and constraints used by OpenERP
      models.
      """
      _name = 'ir.model.constraint'
      _columns = {
          'name': fields.char('Constraint', required=True, size=128, select=1,
              help="PostgreSQL constraint or foreign key name."),
          'model': fields.many2one('ir.model', string='Model',
              required=True, select=1),
          'module': fields.many2one('ir.module.module', string='Module',
              required=True, select=1),
          'type': fields.char('Constraint Type', required=True, size=1, select=1,
              help="Type of the constraint: `f` for a foreign key, "
                  "`u` for other constraints."),
          'date_update': fields.datetime('Update Date'),
          'date_init': fields.datetime('Initialization Date')
      }
  
      _sql_constraints = [
          ('module_name_uniq', 'unique(name, module)',
              'Constraints with the same name are unique per module.'),
      ]
  
      def _module_data_uninstall(self, cr, uid, ids, context=None):
          """
          Delete PostgreSQL foreign keys and constraints tracked by this model.
          """ 
  
          if uid != SUPERUSER_ID and not self.pool.get('ir.model.access').check_groups(cr, uid, "base.group_system"):
              raise except_orm(_('Permission Denied'), (_('Administrator access is required to uninstall a module')))
  
          context = dict(context or {})
  
          ids_set = set(ids)
          ids.sort()
          ids.reverse()
          for data in self.browse(cr, uid, ids, context):
              model = data.model.model
              model_obj = self.pool.get(model)
              name = openerp.tools.ustr(data.name)
              typ = data.type
  
              # double-check we are really going to delete all the owners of this schema element
              cr.execute("""SELECT id from ir_model_constraint where name=%s""", (data.name,))
              external_ids = [x[0] for x in cr.fetchall()]
              if set(external_ids)-ids_set:
                  # as installed modules have defined this element we must not delete it!
                  continue
  
              if typ == 'f':
                  # test if FK exists on this table (it could be on a related m2m table, in which case we ignore it)
                  cr.execute("""SELECT 1 from pg_constraint cs JOIN pg_class cl ON (cs.conrelid = cl.oid)
                                WHERE cs.contype=%s and cs.conname=%s and cl.relname=%s""", ('f', name, model_obj._table))
                  if cr.fetchone():
                      cr.execute('ALTER TABLE "%s" DROP CONSTRAINT "%s"' % (model_obj._table, name),)
                      _logger.info('Dropped FK CONSTRAINT %s@%s', name, model)
  
              if typ == 'u':
                  # test if constraint exists
                  cr.execute("""SELECT 1 from pg_constraint cs JOIN pg_class cl ON (cs.conrelid = cl.oid)
                                WHERE cs.contype=%s and cs.conname=%s and cl.relname=%s""", ('u', name, model_obj._table))
                  if cr.fetchone():
                      cr.execute('ALTER TABLE "%s" DROP CONSTRAINT "%s"' % (model_obj._table, name),)
                      _logger.info('Dropped CONSTRAINT %s@%s', name, model)
  
          self.unlink(cr, uid, ids, context)
  
  class ir_model_relation(Model):
      """
      This model tracks PostgreSQL tables used to implement OpenERP many2many
      relations.
      """
      _name = 'ir.model.relation'
      _columns = {
          'name': fields.char('Relation Name', required=True, size=128, select=1,
              help="PostgreSQL table name implementing a many2many relation."),
          'model': fields.many2one('ir.model', string='Model',
              required=True, select=1),
          'module': fields.many2one('ir.module.module', string='Module',
              required=True, select=1),
          'date_update': fields.datetime('Update Date'),
          'date_init': fields.datetime('Initialization Date')
      }
  
      def _module_data_uninstall(self, cr, uid, ids, context=None):
          """
          Delete PostgreSQL many2many relations tracked by this model.
          """ 
  
          if uid != SUPERUSER_ID and not self.pool.get('ir.model.access').check_groups(cr, uid, "base.group_system"):
              raise except_orm(_('Permission Denied'), (_('Administrator access is required to uninstall a module')))
  
          ids_set = set(ids)
          to_drop_table = []
          ids.sort()
          ids.reverse()
          for data in self.browse(cr, uid, ids, context):
              model = data.model
              name = openerp.tools.ustr(data.name)
  
              # double-check we are really going to delete all the owners of this schema element
              cr.execute("""SELECT id from ir_model_relation where name = %s""", (data.name,))
              external_ids = [x[0] for x in cr.fetchall()]
              if set(external_ids)-ids_set:
                  # as installed modules have defined this element we must not delete it!
                  continue
  
              cr.execute("SELECT 1 FROM information_schema.tables WHERE table_name=%s", (name,))
              if cr.fetchone() and not name in to_drop_table:
                  to_drop_table.append(name)
  
          self.unlink(cr, uid, ids, context)
  
          # drop m2m relation tables
          for table in to_drop_table:
              cr.execute('DROP TABLE %s CASCADE'% table,)
              _logger.info('Dropped table %s', table)
  
          cr.commit()
  
  class ir_model_access(osv.osv):
      _name = 'ir.model.access'
      _columns = {
          'name': fields.char('Name', size=64, required=True, select=True),
          'active': fields.boolean('Active', help='If you uncheck the active field, it will disable the ACL without deleting it (if you delete a native ACL, it will be re-created when you reload the module.'),
          'model_id': fields.many2one('ir.model', 'Object', required=True, domain=[('osv_memory','=', False)], select=True, ondelete='cascade'),
          'group_id': fields.many2one('res.groups', 'Group', ondelete='cascade', select=True),
          'perm_read': fields.boolean('Read Access'),
          'perm_write': fields.boolean('Write Access'),
          'perm_create': fields.boolean('Create Access'),
          'perm_unlink': fields.boolean('Delete Access'),
      }
      _defaults = {
          'active': True,
      }
  
      def check_groups(self, cr, uid, group):
          grouparr  = group.split('.')
          if not grouparr:
              return False
          cr.execute("select 1 from res_groups_users_rel where uid=%s and gid IN (select res_id from ir_model_data where module=%s and name=%s)", (uid, grouparr[0], grouparr[1],))
          return bool(cr.fetchone())
  
      def check_group(self, cr, uid, model, mode, group_ids):
          """ Check if a specific group has the access mode to the specified model"""
          assert mode in ['read','write','create','unlink'], 'Invalid access mode'
  
          if isinstance(model, browse_record):
              assert model._table_name == 'ir.model', 'Invalid model object'
              model_name = model.name
          else:
              model_name = model
  
          if isinstance(group_ids, (int, long)):
              group_ids = [group_ids]
          for group_id in group_ids:
              cr.execute("SELECT perm_" + mode + " "
                     "  FROM ir_model_access a "
                     "  JOIN ir_model m ON (m.id = a.model_id) "
                     " WHERE m.model = %s AND a.active IS True "
                     " AND a.group_id = %s", (model_name, group_id)
                     )
              r = cr.fetchone()
              if r is None:
                  cr.execute("SELECT perm_" + mode + " "
                         "  FROM ir_model_access a "
                         "  JOIN ir_model m ON (m.id = a.model_id) "
                         " WHERE m.model = %s AND a.active IS True "
                         " AND a.group_id IS NULL", (model_name, )
                         )
                  r = cr.fetchone()
  
              access = bool(r and r[0])
              if access:
                  return True
          # pass no groups -> no access
          return False
  
      def group_names_with_access(self, cr, model_name, access_mode):
          """Returns the names of visible groups which have been granted ``access_mode`` on
             the model ``model_name``.
             :rtype: list
          """
          assert access_mode in ['read','write','create','unlink'], 'Invalid access mode: %s' % access_mode
          cr.execute('''SELECT
                          c.name, g.name
                        FROM
                          ir_model_access a
                          JOIN ir_model m ON (a.model_id=m.id)
                          JOIN res_groups g ON (a.group_id=g.id)
                          LEFT JOIN ir_module_category c ON (c.id=g.category_id)
                        WHERE
                          m.model=%s AND
                          a.active IS True AND
                          a.perm_''' + access_mode, (model_name,))
          return [('%s/%s' % x) if x[0] else x[1] for x in cr.fetchall()]
  
      @tools.ormcache()
      def check(self, cr, uid, model, mode='read', raise_exception=True, context=None):
          if uid==1:
              # User root have all accesses
              # TODO: exclude xml-rpc requests
              return True
  
          assert mode in ['read','write','create','unlink'], 'Invalid access mode'
  
          if isinstance(model, browse_record):
              assert model._table_name == 'ir.model', 'Invalid model object'
              model_name = model.model
          else:
              model_name = model
  
          # TransientModel records have no access rights, only an implicit access rule
          if not self.pool.get(model_name):
              _logger.error('Missing model %s' % (model_name, ))
          elif self.pool.get(model_name).is_transient():
              return True
  
          # We check if a specific rule exists
          cr.execute('SELECT MAX(CASE WHEN perm_' + mode + ' THEN 1 ELSE 0 END) '
                     '  FROM ir_model_access a '
                     '  JOIN ir_model m ON (m.id = a.model_id) '
                     '  JOIN res_groups_users_rel gu ON (gu.gid = a.group_id) '
                     ' WHERE m.model = %s '
                     '   AND gu.uid = %s '
                     '   AND a.active IS True '
                     , (model_name, uid,)
                     )
          r = cr.fetchone()[0]
  
          if r is None:
              # there is no specific rule. We check the generic rule
              cr.execute('SELECT MAX(CASE WHEN perm_' + mode + ' THEN 1 ELSE 0 END) '
                         '  FROM ir_model_access a '
                         '  JOIN ir_model m ON (m.id = a.model_id) '
                         ' WHERE a.group_id IS NULL '
                         '   AND m.model = %s '
                         '   AND a.active IS True '
                         , (model_name,)
                         )
              r = cr.fetchone()[0]
  
          if not r and raise_exception:
              groups = '\n\t'.join('- %s' % g for g in self.group_names_with_access(cr, model_name, mode))
              msg_heads = {
                  # Messages are declared in extenso so they are properly exported in translation terms
                  'read': _("Sorry, you are not allowed to access this document."),
                  'write':  _("Sorry, you are not allowed to modify this document."),
                  'create': _("Sorry, you are not allowed to create this kind of document."),
                  'unlink': _("Sorry, you are not allowed to delete this document."),
              }
              if groups:
                  msg_tail = _("Only users with the following access level are currently allowed to do that") + ":\n%s\n\n(" + _("Document model") + ": %s)"
                  msg_params = (groups, model_name)
              else:
                  msg_tail = _("Please contact your system administrator if you think this is an error.") + "\n\n(" + _("Document model") + ": %s)"
                  msg_params = (model_name,)
              _logger.warning('Access Denied by ACLs for operation: %s, uid: %s, model: %s', mode, uid, model_name)
              msg = '%s %s' % (msg_heads[mode], msg_tail)
              raise except_orm(_('Access Denied'), msg % msg_params)
          return r or False
  
      __cache_clearing_methods = []
  
      def register_cache_clearing_method(self, model, method):
          self.__cache_clearing_methods.append((model, method))
  
      def unregister_cache_clearing_method(self, model, method):
          try:
              i = self.__cache_clearing_methods.index((model, method))
              del self.__cache_clearing_methods[i]
          except ValueError:
              pass
  
      def call_cache_clearing_methods(self, cr):
          self.check.clear_cache(self)    # clear the cache of check function
          for model, method in self.__cache_clearing_methods:
              object_ = self.pool.get(model)
              if object_:
                  getattr(object_, method)()
  
      #
      # Check rights on actions
      #
      def write(self, cr, uid, *args, **argv):
          self.call_cache_clearing_methods(cr)
          res = super(ir_model_access, self).write(cr, uid, *args, **argv)
          return res
  
      def create(self, cr, uid, *args, **argv):
          self.call_cache_clearing_methods(cr)
          res = super(ir_model_access, self).create(cr, uid, *args, **argv)
          return res
  
      def unlink(self, cr, uid, *args, **argv):
          self.call_cache_clearing_methods(cr)
          res = super(ir_model_access, self).unlink(cr, uid, *args, **argv)
          return res
  
  class ir_model_data(osv.osv):
      """Holds external identifier keys for records in the database.
         This has two main uses:
  
             * allows easy data integration with third-party systems,
               making import/export/sync of data possible, as records
               can be uniquely identified across multiple systems
             * allows tracking the origin of data installed by OpenERP
               modules themselves, thus making it possible to later
               update them seamlessly.
      """
      _name = 'ir.model.data'
      _order = 'module,model,name'
      def _display_name_get(self, cr, uid, ids, prop, unknow_none, context=None):
          result = {}
          result2 = {}
          for res in self.browse(cr, uid, ids, context=context):
              if res.id:
                  result.setdefault(res.model, {})
                  result[res.model][res.res_id] = res.id
              result2[res.id] = False
  
          for model in result:
              try:
                  r = dict(self.pool.get(model).name_get(cr, uid, result[model].keys(), context=context))
                  for key,val in result[model].items():
                      result2[val] = r.get(key, False)
              except:
                  # some object have no valid name_get implemented, we accept this
                  pass
          return result2
  
      def _complete_name_get(self, cr, uid, ids, prop, unknow_none, context=None):
          result = {}
          for res in self.browse(cr, uid, ids, context=context):
              result[res.id] = (res.module and (res.module + '.') or '')+res.name
          return result
  
      _columns = {
          'name': fields.char('External Identifier', required=True, size=128, select=1,
                              help="External Key/Identifier that can be used for "
                                   "data integration with third-party systems"),
          'complete_name': fields.function(_complete_name_get, type='char', string='Complete ID'),
          'display_name': fields.function(_display_name_get, type='char', string='Record Name'),
          'model': fields.char('Model Name', required=True, size=64, select=1),
          'module': fields.char('Module', required=True, size=64, select=1),
          'res_id': fields.integer('Record ID', select=1,
                                   help="ID of the target record in the database"),
          'noupdate': fields.boolean('Non Updatable'),
          'date_update': fields.datetime('Update Date'),
          'date_init': fields.datetime('Init Date')
      }
      _defaults = {
          'date_init': lambda *a: time.strftime('%Y-%m-%d %H:%M:%S'),
          'date_update': lambda *a: time.strftime('%Y-%m-%d %H:%M:%S'),
          'noupdate': False,
          'module': ''
      }
      _sql_constraints = [
          ('module_name_uniq', 'unique(name, module)', 'You cannot have multiple records with the same external ID in the same module!'),
      ]
  
      def __init__(self, pool, cr):
          osv.osv.__init__(self, pool, cr)
          self.doinit = True
          # also stored in pool to avoid being discarded along with this osv instance
          if getattr(pool, 'model_data_reference_ids', None) is None:
              self.pool.model_data_reference_ids = {}
  
          self.loads = self.pool.model_data_reference_ids
  
      def _auto_init(self, cr, context=None):
          super(ir_model_data, self)._auto_init(cr, context)
          cr.execute('SELECT indexname FROM pg_indexes WHERE indexname = \'ir_model_data_module_name_index\'')
          if not cr.fetchone():
              cr.execute('CREATE INDEX ir_model_data_module_name_index ON ir_model_data (module, name)')
  
      @tools.ormcache()
      def _get_id(self, cr, uid, module, xml_id):
          """Returns the id of the ir.model.data record corresponding to a given module and xml_id (cached) or raise a ValueError if not found"""
          ids = self.search(cr, uid, [('module','=',module), ('name','=', xml_id)])
          if not ids:
              raise ValueError('No such external ID currently defined in the system: %s.%s' % (module, xml_id))
          # the sql constraints ensure us we have only one result
          return ids[0]
  
      @tools.ormcache()
      def get_object_reference(self, cr, uid, module, xml_id):
          """Returns (model, res_id) corresponding to a given module and xml_id (cached) or raise ValueError if not found"""
          data_id = self._get_id(cr, uid, module, xml_id)
          res = self.read(cr, uid, data_id, ['model', 'res_id'])
          if not res['res_id']:
              raise ValueError('No such external ID currently defined in the system: %s.%s' % (module, xml_id))
          return res['model'], res['res_id']
  
      def get_object(self, cr, uid, module, xml_id, context=None):
          """Returns a browsable record for the given module name and xml_id or raise ValueError if not found"""
          res_model, res_id = self.get_object_reference(cr, uid, module, xml_id)
          result = self.pool.get(res_model).browse(cr, uid, res_id, context=context)
          if not result.exists():
              raise ValueError('No record found for unique ID %s.%s. It may have been deleted.' % (module, xml_id))
          return result
  
      def _update_dummy(self,cr, uid, model, module, xml_id=False, store=True):
          if not xml_id:
              return False
          try:
              id = self.read(cr, uid, [self._get_id(cr, uid, module, xml_id)], ['res_id'])[0]['res_id']
              self.loads[(module,xml_id)] = (model,id)
          except:
              id = False
          return id
  
      def clear_caches(self):
          """ Clears all orm caches on the object's methods
  
          :returns: itself
          """
          self._get_id.clear_cache(self)
          self.get_object_reference.clear_cache(self)
          return self
  
      def unlink(self, cr, uid, ids, context=None):
          """ Regular unlink method, but make sure to clear the caches. """
          self.clear_caches()
          return super(ir_model_data,self).unlink(cr, uid, ids, context=context)
  
      def _update(self,cr, uid, model, module, values, xml_id=False, store=True, noupdate=False, mode='init', res_id=False, context=None):
          model_obj = self.pool.get(model)
          if not context:
              context = {}
          # records created during module install should not display the messages of OpenChatter
          context = dict(context, install_mode=True)
          if xml_id and ('.' in xml_id):
              assert len(xml_id.split('.'))==2, _("'%s' contains too many dots. XML ids should not contain dots ! These are used to refer to other modules data, as in module.reference_id") % xml_id
              module, xml_id = xml_id.split('.')
          if (not xml_id) and (not self.doinit):
              return False
          action_id = False
          if xml_id:
              cr.execute('''SELECT imd.id, imd.res_id, md.id, imd.model
                            FROM ir_model_data imd LEFT JOIN %s md ON (imd.res_id = md.id)
                            WHERE imd.module=%%s AND imd.name=%%s''' % model_obj._table,
                            (module, xml_id))
              results = cr.fetchall()
              for imd_id2,res_id2,real_id2,real_model in results:
                  if not real_id2:
                      self._get_id.clear_cache(self, uid, module, xml_id)
                      self.get_object_reference.clear_cache(self, uid, module, xml_id)
                      cr.execute('delete from ir_model_data where id=%s', (imd_id2,))
                      res_id = False
                  else:
                      assert model == real_model, "External ID conflict, %s already refers to a `%s` record,"\
                          " you can't define a `%s` record with this ID." % (xml_id, real_model, model)
                      res_id,action_id = res_id2,imd_id2
  
          if action_id and res_id:
              model_obj.write(cr, uid, [res_id], values, context=context)
              self.write(cr, uid, [action_id], {
                  'date_update': time.strftime('%Y-%m-%d %H:%M:%S'),
                  },context=context)
          elif res_id:
              model_obj.write(cr, uid, [res_id], values, context=context)
              if xml_id:
                  self.create(cr, uid, {
                      'name': xml_id,
                      'model': model,
                      'module':module,
                      'res_id':res_id,
                      'noupdate': noupdate,
                      },context=context)
                  if model_obj._inherits:
                      for table in model_obj._inherits:
                          inherit_id = model_obj.browse(cr, uid,
                                  res_id,context=context)[model_obj._inherits[table]]
                          self.create(cr, uid, {
                              'name': xml_id + '_' + table.replace('.', '_'),
                              'model': table,
                              'module': module,
                              'res_id': inherit_id.id,
                              'noupdate': noupdate,
                              },context=context)
          else:
              if mode=='init' or (mode=='update' and xml_id):
                  res_id = model_obj.create(cr, uid, values, context=context)
                  if xml_id:
                      self.create(cr, uid, {
                          'name': xml_id,
                          'model': model,
                          'module': module,
                          'res_id': res_id,
                          'noupdate': noupdate
                          },context=context)
                      if model_obj._inherits:
                          for table in model_obj._inherits:
                              inherit_id = model_obj.browse(cr, uid,
                                      res_id,context=context)[model_obj._inherits[table]]
                              self.create(cr, uid, {
                                  'name': xml_id + '_' + table.replace('.', '_'),
                                  'model': table,
                                  'module': module,
                                  'res_id': inherit_id.id,
                                  'noupdate': noupdate,
                                  },context=context)
          if xml_id and res_id:
              self.loads[(module, xml_id)] = (model, res_id)
              for table, inherit_field in model_obj._inherits.iteritems():
                  inherit_id = model_obj.read(cr, uid, res_id,
                          [inherit_field])[inherit_field]
                  self.loads[(module, xml_id + '_' + table.replace('.', '_'))] = (table, inherit_id)
          return res_id
  
      def ir_set(self, cr, uid, key, key2, name, models, value, replace=True, isobject=False, meta=None, xml_id=False):
          if isinstance(models[0], (list, tuple)):
              model,res_id = models[0]
          else:
              res_id=None
              model = models[0]
  
          if res_id:
              where = ' and res_id=%s' % (res_id,)
          else:
              where = ' and (res_id is null)'
  
          if key2:
              where += ' and key2=\'%s\'' % (key2,)
          else:
              where += ' and (key2 is null)'
  
          cr.execute('select * from ir_values where model=%s and key=%s and name=%s'+where,(model, key, name))
          res = cr.fetchone()
          if not res:
              ir_values_obj = pooler.get_pool(cr.dbname).get('ir.values')
              ir_values_obj.set(cr, uid, key, key2, name, models, value, replace, isobject, meta)
          elif xml_id:
              cr.execute('UPDATE ir_values set value=%s WHERE model=%s and key=%s and name=%s'+where,(value, model, key, name))
          return True
  
      def _module_data_uninstall(self, cr, uid, modules_to_remove, context=None):
          """Deletes all the records referenced by the ir.model.data entries
          ``ids`` along with their corresponding database backed (including
          dropping tables, columns, FKs, etc, as long as there is no other
          ir.model.data entry holding a reference to them (which indicates that
          they are still owned by another module). 
          Attempts to perform the deletion in an appropriate order to maximize
          the chance of gracefully deleting all records.
          This step is performed as part of the full uninstallation of a module.
          """ 
  
          ids = self.search(cr, uid, [('module', 'in', modules_to_remove)])
  
          if uid != 1 and not self.pool.get('ir.model.access').check_groups(cr, uid, "base.group_system"):
              raise except_orm(_('Permission Denied'), (_('Administrator access is required to uninstall a module')))
  
          context = dict(context or {})
          context[MODULE_UNINSTALL_FLAG] = True # enable model/field deletion
  
          ids_set = set(ids)
          wkf_todo = []
          to_unlink = []
          ids.sort()
          ids.reverse()
          for data in self.browse(cr, uid, ids, context):
              model = data.model
              res_id = data.res_id
  
              pair_to_unlink = (model, res_id)
              if pair_to_unlink not in to_unlink:
                  to_unlink.append(pair_to_unlink)
  
              if model == 'workflow.activity':
                  # Special treatment for workflow activities: temporarily revert their
                  # incoming transition and trigger an update to force all workflow items
                  # to move out before deleting them
                  cr.execute('select res_type,res_id from wkf_instance where id IN (select inst_id from wkf_workitem where act_id=%s)', (res_id,))
                  wkf_todo.extend(cr.fetchall())
                  cr.execute("update wkf_transition set condition='True', group_id=NULL, signal=NULL,act_to=act_from,act_from=%s where act_to=%s", (res_id,res_id))
  
          wf_service = netsvc.LocalService("workflow")
          for model,res_id in wkf_todo:
              try:
                  wf_service.trg_write(uid, model, res_id, cr)
              except Exception:
                  _logger.info('Unable to force processing of workflow for item %s@%s in order to leave activity to be deleted', res_id, model, exc_info=True)
  
          def unlink_if_refcount(to_unlink):
              for model, res_id in to_unlink:
                  external_ids = self.search(cr, uid, [('model', '=', model),('res_id', '=', res_id)])
                  if set(external_ids)-ids_set:
                      # if other modules have defined this record, we must not delete it
                      continue
                  _logger.info('Deleting %s@%s', res_id, model)
                  try:
                      cr.execute('SAVEPOINT record_unlink_save')
                      self.pool.get(model).unlink(cr, uid, [res_id], context=context)
                  except Exception:
                      _logger.info('Unable to delete %s@%s', res_id, model, exc_info=True)
                      cr.execute('ROLLBACK TO SAVEPOINT record_unlink_save')
                  else:
                      cr.execute('RELEASE SAVEPOINT record_unlink_save')
  
          # Remove non-model records first, then model fields, and finish with models
          unlink_if_refcount((model, res_id) for model, res_id in to_unlink
                                  if model not in ('ir.model','ir.model.fields'))
          unlink_if_refcount((model, res_id) for model, res_id in to_unlink
                                  if model == 'ir.model.fields')
  
          ir_model_relation = self.pool.get('ir.model.relation')
          ir_module_module = self.pool.get('ir.module.module')
          modules_to_remove_ids = ir_module_module.search(cr, uid, [('name', 'in', modules_to_remove)])
          relation_ids = ir_model_relation.search(cr, uid, [('module', 'in', modules_to_remove_ids)])
          ir_model_relation._module_data_uninstall(cr, uid, relation_ids, context)
  
          unlink_if_refcount((model, res_id) for model, res_id in to_unlink
                                  if model == 'ir.model')
  
          cr.commit()
  
          self.unlink(cr, uid, ids, context)
  
      def _process_end(self, cr, uid, modules):
          """ Clear records removed from updated module data.
          This method is called at the end of the module loading process.
          It is meant to removed records that are no longer present in the
          updated data. Such records are recognised as the one with an xml id
          and a module in ir_model_data and noupdate set to false, but not
          present in self.loads.
          """
          if not modules:
              return True
          to_unlink = []
          cr.execute("""SELECT id,name,model,res_id,module FROM ir_model_data
                        WHERE module IN %s AND res_id IS NOT NULL AND noupdate=%s
                        ORDER BY id DESC""",
                        (tuple(modules), False))
          for (id, name, model, res_id, module) in cr.fetchall():
              if (module,name) not in self.loads:
                  to_unlink.append((model,res_id))
          if not config.get('import_partial'):
              for (model, res_id) in to_unlink:
                  if self.pool.get(model):
                      _logger.info('Deleting %s@%s', res_id, model)
                      self.pool.get(model).unlink(cr, uid, [res_id])
  
  # vim:expandtab:smartindent:tabstop=4:softtabstop=4:shiftwidth=4:
  