Merge pull request #101 from funkybob/issue-34

Attempt to carry over extras(select) values from parent

AUTHORS.rst

@@ -25,3 +25,4 @@ Travis Swicegood <travis@domain51.com>
 Trey Hunner <trey@treyhunner.com>
 zyegfryed
 Filipe Ximenes <filipeximenes@gmail.com>
+Curtis Maloney <curtis@tinbrain.net>

CHANGES.rst

@@ -42,6 +42,8 @@ master (unreleased)
 * MonitorField now accepts a 'when' parameter. It will update only when the field
   changes to one of the values specified.
 
+* Improve `InheritanceManager` so any attributes added by using extra(select)
+  will be propagated onto children.
 
 1.5.0 (2013.08.29)
 ------------------

model_utils/managers.py

@@ -70,6 +70,7 @@ class InheritanceQuerySetMixin(object):
     def iterator(self):
         iter = super(InheritanceQuerySetMixin, self).iterator()
         if getattr(self, 'subclasses', False):
+            extras = tuple(self.query.extra.keys())
             # sort the subclass names longest first,
             # so with 'a' and 'a__b' it goes as deep as possible
             subclasses = sorted(self.subclasses, key=len, reverse=True)
@@ -86,6 +87,9 @@ class InheritanceQuerySetMixin(object):
                     for k in self._annotated:
                         setattr(sub_obj, k, getattr(obj, k))
 
+                for k in extras:
+                    setattr(sub_obj, k, getattr(obj, k))
+
                 yield sub_obj
         else:
             for obj in iter:

model_utils/tests/tests.py

@@ -974,6 +974,14 @@ class InheritanceManagerUsingModelsTests(TestCase):
         self.assertEqual(set(results.subclasses),
                          set(expected_related_names))
 
+    def test_extras_descend(self):
+        """
+        Ensure that extra(select=) values are copied onto sub-classes.
+        """
+        results = InheritanceManagerTestParent.objects.select_subclasses().extra(
+            select={'foo': 'id + 1'}
+        )
+        self.assertTrue(all(result.foo == (result.id + 1) for result in results))
 
 
 class InheritanceManagerRelatedTests(InheritanceManagerTests):