As can be seen below, the generic_models attribute of the BaseModel? class is not properly inherited by the child class. In the TestModel? example where no inheritance takes place, it works fine.
Code:
from django.db import models
from django.contrib.contenttypes import generic
from django.contrib.contenttypes.models import ContentType
class GenericModel(models.Model):
# Generic relation-related attributes
content_type = models.ForeignKey(ContentType)
content_object = generic.GenericForeignKey()
object_id = models.PositiveIntegerField()
class BaseModel(models.Model):
generic_models = generic.GenericRelation(GenericModel)
class Meta:
abstract = True
class ChildModel(BaseModel):
name = models.CharField(max_length=31)
class TestModel(models.Model):
generic_models = generic.GenericRelation(GenericModel)
Test case:
>>> test_child = TestModel()
>>> test_child.generic_models # Works
<django.contrib.contenttypes.generic.GenericRelatedObjectManager object at 0x01FBCED0>
>>> child = ChildModel(name='Test')
>>> child.generic_models # Raises AttributeError
D:\Python25\lib\site-packages\django\contrib\contenttypes\generic.py in __get__(self, instance, instance_type)
190 join_table = qn(self.field.m2m_db_table()),
191 source_col_name = qn(self.field.m2m_column_name()),
--> 192 target_col_name = qn(self.field.m2m_reverse_name()),
193 content_type = ContentType.objects.get_for_model(self.field.model),
194 content_type_field_name = self.field.content_type_field_name,
D:\Python25\lib\site-packages\django\contrib\contenttypes\generic.py in m2m_reverse_name(self)
132
133 def m2m_reverse_name(self):
--> 134 return self.model._meta.pk.column
135
136 def contribute_to_class(self, cls, name):
AttributeError: 'NoneType' object has no attribute 'column'
