+ return super(TreeEntity, self).relationships
+
+ class Meta:
+ abstract = True
+
+
+class InheritableTreeEntity(TreeEntity):
+ instance_type = models.ForeignKey(ContentType, editable=False)
+
+ def save(self, force_insert=False, force_update=False):
+ if not hasattr(self, 'instance_type_ptr'):
+ self.instance_type = ContentType.objects.get_for_model(self.__class__)
+ super(InheritableTreeEntity, self).save(force_insert, force_update)
+
+ @property
+ def instance(self):
+ try:
+ return self.instance_type.get_object_for_this_type(id=self.id)
+ except:
+ return None
+
+ def get_path(self, pathsep='/', field='slug'):
+ path = getattr(self.instance, field, getattr(self.instance, 'slug', '?'))
+ parent = self.parent
+ while parent:
+ path = getattr(parent.instance, field, getattr(parent.instance, 'slug', '?')) + pathsep + path
+ parent = parent.parent
+ return path
+ path = property(get_path)
+
+ @property
+ def attributes(self):
+ if self.parent:
+ return QuerySetMapper(self.instance.attribute_set, passthrough=self.parent.instance.attributes)
+ return QuerySetMapper(self.instance.attribute_set)
+
+ @property
+ def relationships(self):
+ if self.parent:
+ return QuerySetMapper(self.instance.relationship_set, passthrough=self.parent.instance.relationships)
+ return QuerySetMapper(self.instance.relationship_set)
+
+ class Meta:
+ abstract = True
+
+
+class Node(InheritableTreeEntity):
+ accepts_subpath = False
+
+ def render_to_response(self, request, path=None, subpath=None):
+ return HttpResponseServerError()
+
+ class Meta:
+ unique_together = (('parent', 'slug'),)
+
+
+class MultiNode(Node):
+ accepts_subpath = True
+
+ urlpatterns = []
+
+ def render_to_response(self, request, path=None, subpath=None):
+ if not subpath:
+ subpath = ""
+ subpath = "/" + subpath
+ from django.core.urlresolvers import resolve
+ view, args, kwargs = resolve(subpath, urlconf=self)
+ return view(request, *args, **kwargs)