Fix support for proxy models in formsets and admin inlines

Author: vdboor

polymorphic/admin/generic.py

@@ -42,7 +42,7 @@ def content_type(self):
             Expose the ContentType that the child relates to.
             This can be used for the ``polymorphic_ctype`` field.
             """
-            return ContentType.objects.get_for_model(self.model)
+            return ContentType.objects.get_for_model(self.model, for_concrete_model=False)
 
         def get_formset_child(self, request, obj=None, **kwargs):
             # Similar to GenericInlineModelAdmin.get_formset(),

polymorphic/admin/helpers.py

@@ -42,7 +42,7 @@ def __iter__(self):
         """
         for form, original in zip(self.formset.initial_forms, self.formset.get_queryset()):
             # Output the form
-            model = original.get_real_concrete_instance_class()
+            model = original.get_real_instance_class()
             child_inline = self.opts.get_child_inline_instance(model)
             view_on_site_url = self.opts.get_view_on_site_url(original)
 

polymorphic/formsets/models.py

@@ -14,7 +14,6 @@ class UnsupportedChildType(LookupError):
     pass
 
 
-
 class PolymorphicFormSetChild(object):
     """
     Metadata to define the inline of a polymorphic child.
@@ -46,7 +45,7 @@ def content_type(self):
         Expose the ContentType that the child relates to.
         This can be used for the ''polymorphic_ctype'' field.
         """
-        return ContentType.objects.get_for_model(self.model)
+        return ContentType.objects.get_for_model(self.model, for_concrete_model=False)
 
     def get_form(self, **kwargs):
         """
@@ -161,7 +160,7 @@ def _construct_form(self, i, **kwargs):
         if self.is_bound:
             if 'instance' in defaults:
                 # Object is already bound to a model, won't change the content type
-                model = defaults['instance'].get_real_concrete_instance_class()  # respect proxy models
+                model = defaults['instance'].get_real_instance_class()  # allow proxy models
             else:
                 # Extra or empty form, use the provided type.
                 # Note this completely tru
@@ -177,7 +176,7 @@ def _construct_form(self, i, **kwargs):
                     raise UnsupportedChildType("Child model type {0} is not part of the formset".format(model))
         else:
             if 'instance' in defaults:
-                model = defaults['instance'].get_real_concrete_instance_class()  # respect proxy models
+                model = defaults['instance'].get_real_instance_class()  # allow proxy models
             elif 'polymorphic_ctype' in defaults.get('initial', {}):
                 model = defaults['initial']['polymorphic_ctype'].model_class()
             elif i < len(self.queryset_data):