ldapdb/models/base.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # django-ldapdb
   4 # Copyright (c) 2009-2010, Bolloré telecom
   5 # All rights reserved.
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  33 #
  34
  35 import ldap
  36 import logging
  37
  38 import django.db.models
  39 from django.db.models import signals
  40
  41 import ldapdb
  42 from ldapdb.models.query import QuerySet
  43
  44 class ModelBase(django.db.models.base.ModelBase):
  45     """
  46     Metaclass for all LDAP models.
  47     """
  48     def __new__(cls, name, bases, attrs):
  49         super_new = super(ModelBase, cls).__new__
  50         new_class = super_new(cls, name, bases, attrs)
  51
  52         # patch manager to use our own QuerySet class
  53         if not new_class._meta.abstract:
  54             def get_query_set():
  55                 return QuerySet(new_class)
  56             new_class.objects.get_query_set = get_query_set
  57             new_class._default_manager.get_query_set = get_query_set
  58
  59         return new_class
  60
  61 class Model(django.db.models.base.Model):
  62     """
  63     Base class for all LDAP models.
  64     """
  65     __metaclass__ = ModelBase
  66
  67     dn = django.db.models.fields.CharField(max_length=200)
  68
  69     # meta-data
  70     base_dn = None
  71     search_scope = ldap.SCOPE_SUBTREE
  72     object_classes = ['top']
  73
  74     def __init__(self, *args, **kwargs):
  75         super(Model, self).__init__(*args, **kwargs)
  76         self.saved_pk = self.pk
  77
  78     def _collect_sub_objects(self, seen_objs, parent=None, nullable=False):
  79         """
  80         This private API seems to be called by the admin interface in django 1.2
  81         """
  82         pk_val = self._get_pk_val()
  83         seen_objs.add(self.__class__, pk_val, self,
  84                       type(parent), parent, nullable)
  85
  86     def build_rdn(self):
  87         """
  88         Build the Relative Distinguished Name for this entry.
  89         """
  90         bits = []
  91         for field in self._meta.fields:
  92             if field.db_column and field.primary_key:
  93                 bits.append("%s=%s" % (field.db_column, getattr(self, field.name)))
  94         if not len(bits):
  95             raise Exception("Could not build Distinguished Name")
  96         return '+'.join(bits)
  97
  98     def build_dn(self):
  99         """
 100         Build the Distinguished Name for this entry.
 101         """
 102         return "%s,%s" % (self.build_rdn(), self.base_dn)
 103         raise Exception("Could not build Distinguished Name")
 104
 105     def delete(self):
 106         """
 107         Delete this entry.
 108         """
 109         using = using or router.db_for_write(self.__class__, instance=self)
 110         connection = connections[using]
 111         logging.debug("Deleting LDAP entry %s" % self.dn)
 112         connection.delete_s(self.dn)
 113         signals.post_delete.send(sender=self.__class__, instance=self)
 114
 115     def save(self, using=None):
 116         """
 117         Saves the current instance.
 118         """
 119         using = using or router.db_for_write(self.__class__, instance=self)
 120         connection = connections[using]
 121         if not self.dn:
 122             # create a new entry
 123             record_exists = False
 124             entry = [('objectClass', self.object_classes)]
 125             new_dn = self.build_dn()
 126
 127             for field in self._meta.fields:
 128                 if not field.db_column:
 129                     continue
 130                 value = getattr(self, field.name)
 131                 if value:
 132                     entry.append((field.db_column, field.get_db_prep_save(value, connection=connection)))
 133
 134             logging.debug("Creating new LDAP entry %s" % new_dn)
 135             connection.add_s(new_dn, entry)
 136
 137             # update object
 138             self.dn = new_dn
 139
 140         else:
 141             # update an existing entry
 142             record_exists = True
 143             modlist = []
 144             orig = self.__class__.objects.get(pk=self.saved_pk)
 145             for field in self._meta.fields:
 146                 if not field.db_column:
 147                     continue
 148                 old_value = getattr(orig, field.name, None)
 149                 new_value = getattr(self, field.name, None)
 150                 if old_value != new_value:
 151                     if new_value:
 152                         modlist.append((ldap.MOD_REPLACE, field.db_column, field.get_db_prep_save(new_value, connection=connection)))
 153                     elif old_value:
 154                         modlist.append((ldap.MOD_DELETE, field.db_column, None))
 155
 156             if len(modlist):
 157                 # handle renaming
 158                 new_dn = self.build_dn()
 159                 if new_dn != self.dn:
 160                     logging.debug("Renaming LDAP entry %s to %s" % (self.dn, new_dn))
 161                     connection.rename_s(self.dn, self.build_rdn())
 162                     self.dn = new_dn
 163
 164                 logging.debug("Modifying existing LDAP entry %s" % self.dn)
 165                 connection.modify_s(self.dn, modlist)
 166             else:
 167                 logging.debug("No changes to be saved to LDAP entry %s" % self.dn)
 168
 169         # done
 170         self.saved_pk = self.pk
 171         signals.post_save.send(sender=self.__class__, instance=self, created=(not record_exists))
 172
 173     @classmethod
 174     def scoped(base_class, base_dn):
 175         """
 176         Returns a copy of the current class with a different base_dn.
 177         """
 178         import new
 179         import re
 180         suffix = re.sub('[=,]', '_', base_dn)
 181         name = "%s_%s" % (base_class.__name__, str(suffix))
 182         new_class = new.classobj(name, (base_class,), {'base_dn': base_dn, '__module__': base_class.__module__})
 183         return new_class
 184