Merge branch 'field-tracker-inheritance'

Conflicts:
	CHANGES.rst

CHANGES.rst

@@ -11,6 +11,8 @@ master (unreleased)
   ``update_fields`` in which there are untracked fields. Thanks Mikhail
   Silonov. (Merge of GH-70, fixes GH-71).
 
+* Fixed ``FieldTracker`` usage on inherited models.  Fixes GH-57.
+
 
 1.4.0 (2013.06.03)
 ------------------

model_utils/tests/models.py

@@ -271,6 +271,10 @@ class TrackedMultiple(models.Model):
     number_tracker = FieldTracker(fields=['number'])
 
 
+class InheritedTracked(Tracked):
+    name2 = models.CharField(max_length=20)
+
+
 class ModelTracked(models.Model):
     name = models.CharField(max_length=20)
     number = models.IntegerField()
@@ -300,6 +304,9 @@ class ModelTrackedMultiple(models.Model):
     name_tracker = ModelTracker(fields=['name'])
     number_tracker = ModelTracker(fields=['number'])
 
+class InheritedModelTracked(ModelTracked):
+    name2 = models.CharField(max_length=20)
+
 
 class StatusFieldDefaultFilled(models.Model):
     STATUS = Choices((0, "no", "No"), (1, "yes", "Yes"))

model_utils/tests/tests.py

@@ -25,9 +25,9 @@ from model_utils.tests.models import (
     InheritanceManagerTestChild2, TimeStamp, Post, Article, Status,
     StatusPlainTuple, TimeFrame, Monitored, StatusManagerAdded,
     TimeFrameManagerAdded, Dude, SplitFieldAbstractParent, Car, Spot,
-    ModelTracked, ModelTrackedFK, ModelTrackedNotDefault, ModelTrackedMultiple,
+    ModelTracked, ModelTrackedFK, ModelTrackedNotDefault, ModelTrackedMultiple, InheritedModelTracked,
     Tracked, TrackedFK, TrackedNotDefault, TrackedNonFieldAttr,
-    TrackedMultiple, StatusFieldDefaultFilled, StatusFieldDefaultNotFilled)
+    TrackedMultiple, InheritedTracked, StatusFieldDefaultFilled, StatusFieldDefaultNotFilled)
 
 
 
@@ -1114,6 +1114,16 @@ class FieldTrackerForeignKeyTests(FieldTrackerTestCase):
         self.assertCurrent(fk=self.instance.fk_id)
 
 
+class InheritedFieldTrackerTests(FieldTrackerTests):
+
+    tracked_class = InheritedTracked
+
+    def test_child_fields_not_tracked(self):
+        self.name2 = 'test'
+        self.assertEqual(self.tracker.previous('name2'), None)
+        self.assertRaises(FieldError, self.tracker.has_changed, 'name2')
+
+
 class ModelTrackerTests(FieldTrackerTests):
 
     tracked_class = ModelTracked
@@ -1237,3 +1247,13 @@ class ModelTrackerForeignKeyTests(FieldTrackerForeignKeyTests):
         self.assertChanged(fk=self.old_fk)
         self.assertPrevious(fk=self.old_fk)
         self.assertCurrent(fk=self.instance.fk)
+
+
+class InheritedModelTrackerTests(ModelTrackerTests):
+
+    tracked_class = InheritedModelTracked
+
+    def test_child_fields_not_tracked(self):
+        self.name2 = 'test'
+        self.assertEqual(self.tracker.previous('name2'), None)
+        self.assertTrue(self.tracker.has_changed('name2'))

model_utils/tracker.py

@@ -71,10 +71,13 @@ class FieldTracker(object):
             self.fields = (field.attname for field in sender._meta.local_fields)
         self.fields = set(self.fields)
         self.field_map = self.get_field_map(sender)
-        models.signals.post_init.connect(self.initialize_tracker, sender=sender)
+        models.signals.post_init.connect(self.initialize_tracker)
+        self.model_class = sender
         setattr(sender, self.name, self)
 
     def initialize_tracker(self, sender, instance, **kwargs):
+        if not isinstance(instance, self.model_class):
+            return  # Only init instances of given model (including children)
         tracker = self.tracker_class(instance, self.fields, self.field_map)
         setattr(instance, self.attname, tracker)
         tracker.set_saved_fields()