Initial import of existing codebase.

evesde/models/utils.py

@@ -0,0 +1,30 @@
+from django.db.models.fields.related import SingleRelatedObjectDescriptor
+from django.db.models.query import QuerySet
+
+
+class InheritanceQuerySet(QuerySet):
+    def select_subclasses(self, *subclasses):
+        if not subclasses:
+            subclasses = [o for o in dir(self.model)
+                          if isinstance(getattr(self.model, o), SingleRelatedObjectDescriptor)\
+                          and issubclass(getattr(self.model,o).related.model, self.model)]
+        new_qs = self.select_related(*subclasses)
+        new_qs.subclasses = subclasses
+        return new_qs
+
+    def _clone(self, klass=None, setup=False, **kwargs):
+        try:
+            kwargs.update({'subclasses': self.subclasses})
+        except AttributeError:
+            pass
+        return super(InheritanceQuerySet, self)._clone(klass, setup, **kwargs)
+
+    def iterator(self):
+        iter = super(InheritanceQuerySet, self).iterator()
+        if getattr(self, 'subclasses', False):
+            for obj in iter:
+                obj = [getattr(obj, s) for s in self.subclasses if getattr(obj, s)] or [obj]
+                yield obj[0]
+        else:
+            for obj in iter:
+                yield obj