Fixed #7215 -- Create correct reverse-relation accessors when using abstract base classes. Patch from Joel Watts.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@7762 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -376,6 +376,7 @@ answer newbie questions, and generally made Django that much better:
     Wang Chun <wangchun@exoweb.net>
     Filip Wasilewski <filip.wasilewski@gmail.com>
     Dan Watson <http://theidioteque.net/>
+    Joel Watts <joel@joelwatts.com>
     Chris Wesseling <Chris.Wesseling@cwi.nl>
     James Wheare <django@sparemint.com>
     charly.wilhelm@gmail.com

django/db/models/fields/related.py

@@ -103,13 +103,15 @@ class RelatedField(object):
 
         if hasattr(sup, 'contribute_to_class'):
             sup.contribute_to_class(cls, name)
+
+        if not cls._meta.abstract and self.rel.related_name:
+            self.rel.related_name = self.rel.related_name % {'class': cls.__name__.lower()}
+
         other = self.rel.to
         if isinstance(other, basestring):
             add_lazy_relation(cls, self, other)
         else:
             self.do_related_class(other, cls)
-        if not cls._meta.abstract and self.rel.related_name:
-            self.rel.related_name = self.rel.related_name % {'class': cls.__name__.lower()}
 
     def set_attributes_from_rel(self):
         self.name = self.name or (self.rel.to._meta.object_name.lower() + '_' + self.rel.to._meta.pk.name)
@@ -119,6 +121,7 @@ class RelatedField(object):
     def do_related_class(self, other, cls):
         self.set_attributes_from_rel()
         related = RelatedObject(other, cls, self)
+        if not cls._meta.abstract:
             self.contribute_to_related_class(other, related)
 
     def get_db_prep_lookup(self, lookup_type, value):

tests/modeltests/model_inheritance/models.py

@@ -38,6 +38,29 @@ class Student(CommonInfo):
     class Meta:
         pass
 
+#
+# Abstract base classes with related models
+#
+
+class Post(models.Model):
+    title = models.CharField(max_length=50)
+
+class Attachment(models.Model):
+    post = models.ForeignKey(Post, related_name='attached_%(class)s_set')
+    content = models.TextField()
+
+    class Meta:
+        abstract = True
+
+    def __unicode__(self):
+        return self.content
+
+class Comment(Attachment):
+    is_spam = models.BooleanField()
+
+class Link(Attachment):
+    url = models.URLField()
+
 #
 # Multi-table inheritance
 #
@@ -128,9 +151,25 @@ Traceback (most recent call last):
     ...
 AttributeError: type object 'CommonInfo' has no attribute 'objects'
 
-# The Place/Restaurant/ItalianRestaurant models, on the other hand, all exist
+# Create a Post
-# as independent models. However, the subclasses also have transparent access
+>>> post = Post(title='Lorem Ipsum')
-# to the fields of their ancestors.
+>>> post.save()
+
+# The Post model has distinct accessors for the Comment and Link models.
+>>> post.attached_comment_set.create(content='Save $ on V1agr@', is_spam=True)
+<Comment: Save $ on V1agr@>
+>>> post.attached_link_set.create(content='The Web framework for perfectionists with deadlines.', url='http://www.djangoproject.com/')
+<Link: The Web framework for perfectionists with deadlines.>
+
+# The Post model doesn't have an attribute called 'attached_%(class)s_set'.
+>>> getattr(post, 'attached_%(class)s_set')
+Traceback (most recent call last):
+    ...
+AttributeError: 'Post' object has no attribute 'attached_%(class)s_set'
+
+# The Place/Restaurant/ItalianRestaurant models all exist as independent
+# models. However, the subclasses also have transparent access to the fields of
+# their ancestors.
 
 # Create a couple of Places.
 >>> p1 = Place(name='Master Shakes', address='666 W. Jersey')