Merge branch 'proxy_models_15' - add proxy model support!

example/pexp/admin.py

@@ -61,3 +61,15 @@ if 'UUIDModelA' in globals():
 
     admin.site.register(UUIDModelA, UUIDModelAAdmin)
 
+
+class ProxyChildAdmin(PolymorphicChildModelAdmin):
+    base_model = ProxyBase
+
+class ProxyAdmin(PolymorphicParentModelAdmin):
+    base_model = ProxyBase
+    child_models = (
+        (ProxyA, ProxyChildAdmin),
+        (ProxyB, ProxyChildAdmin),
+    )
+
+admin.site.register(ProxyBase, ProxyAdmin)

example/pexp/models.py

@@ -47,3 +47,26 @@ if 'UUIDField' in globals():
         field2 = models.CharField(max_length=10)
     class UUIDModelC(UUIDModelB):
         field3 = models.CharField(max_length=10)
+
+class ProxyBase(PolymorphicModel):
+    title = models.CharField(max_length=200)
+
+    def __unicode__(self):
+        return u"<ProxyBase[type={0}]: {1}>".format(self.polymorphic_ctype, self.title)
+
+    class Meta:
+        ordering = ('title',)
+
+class ProxyA(ProxyBase):
+    class Meta:
+        proxy = True
+
+    def __unicode__(self):
+        return u"<ProxyA: {0}>".format(self.title)
+
+class ProxyB(ProxyBase):
+    class Meta:
+        proxy = True
+
+    def __unicode__(self):
+        return u"<ProxyB: {0}>".format(self.title)

polymorphic/__init__.py

@@ -6,6 +6,7 @@ Copyright:
 This code and affiliated files are (C) by Bert Constantin and individual contributors.
 Please see LICENSE and AUTHORS for more information.
 """
+import django
 from polymorphic_model import PolymorphicModel
 from manager import PolymorphicManager
 from query import PolymorphicQuerySet
@@ -26,32 +27,33 @@ def get_version():
     return version
 
 
-# Proxied models need to have it's own ContentType
+# Monkey-patch Django < 1.5 to allow ContentTypes for proxy models.
+if django.VERSION[:2] < (1, 5): 
+    from django.contrib.contenttypes.models import ContentTypeManager
+    from django.utils.encoding import smart_unicode
 
+    def get_for_model(self, model, for_concrete_model=True):
+        from django.utils.encoding import smart_unicode
 
-from django.contrib.contenttypes.models import ContentTypeManager
+        if for_concrete_model:
-from django.utils.encoding import smart_unicode
+            model = model._meta.concrete_model
+        elif model._deferred:
+            model = model._meta.proxy_for_model
 
+        opts = model._meta
+
+        try:
+            ct = self._get_from_cache(opts)
+        except KeyError:
+            ct, created = self.get_or_create(
+                app_label = opts.app_label,
+                model = opts.object_name.lower(),
+                defaults = {'name': smart_unicode(opts.verbose_name_raw)},
+            )
+            self._add_to_cache(self.db, ct)
+
+        return ct
+
+    ContentTypeManager.get_for_model__original = ContentTypeManager.get_for_model
+    ContentTypeManager.get_for_model = get_for_model
 
-def get_for_proxied_model(self, model):
-    """
-    Returns the ContentType object for a given model, creating the
-    ContentType if necessary. Lookups are cached so that subsequent lookups
-    for the same model don't hit the database.
-    """
-    opts = model._meta
-    key = (opts.app_label, opts.object_name.lower())
-    try:
-        ct = self.__class__._cache[self.db][key]
-    except KeyError:
-        # Load or create the ContentType entry. The smart_unicode() is
-        # needed around opts.verbose_name_raw because name_raw might be a
-        # django.utils.functional.__proxy__ object.
-        ct, created = self.get_or_create(
-            app_label=opts.app_label,
-            model=opts.object_name.lower(),
-            defaults={'name': smart_unicode(opts.verbose_name_raw)},
-        )
-        self._add_to_cache(self.db, ct)
-    return ct
-ContentTypeManager.get_for_proxied_model = get_for_proxied_model

polymorphic/admin.py

@@ -140,7 +140,7 @@ class PolymorphicParentModelAdmin(admin.ModelAdmin):
         """
         choices = []
         for model, _ in self.get_child_models():
-            ct = ContentType.objects.get_for_model(model)
+            ct = ContentType.objects.get_for_model(model, for_concrete_model=False)
             choices.append((ct.id, model._meta.verbose_name))
         return choices
 

polymorphic/base.py

@@ -140,6 +140,11 @@ class PolymorphicModelBase(ModelBase):
                     self.validate_model_manager(manager, self.__name__, key)
                 add_managers.append((base.__name__, key, manager))
                 add_managers_keys.add(key)
+
+        # The ordering in the base.__dict__ may randomly change depending on which method is added.
+        # Make sure base_objects is on top, and 'objects' and '_default_manager' follow afterwards.
+        # This makes sure that the _base_manager is also assigned properly.
+        add_managers = sorted(add_managers, key=lambda item: item[2].creation_counter, reverse=True)
         return add_managers
 
     @classmethod

polymorphic/polymorphic_model.py

@@ -85,7 +85,7 @@ class PolymorphicModel(models.Model):
         (used by PolymorphicQuerySet._get_real_instances)
         """
         if not self.polymorphic_ctype_id:
-            self.polymorphic_ctype = ContentType.objects.get_for_model(self)
+            self.polymorphic_ctype = ContentType.objects.get_for_model(self, for_concrete_model=False)
 
     def save(self, *args, **kwargs):
         """Overridden model save function which supports the polymorphism
@@ -103,6 +103,12 @@ class PolymorphicModel(models.Model):
         # so we use the following version, which uses the CopntentType manager cache
         return ContentType.objects.get_for_id(self.polymorphic_ctype_id).model_class()
 
+    def get_real_concrete_instance_class_id(self):
+        return ContentType.objects.get_for_model(self.get_real_instance_class(), for_concrete_model=True).pk
+
+    def get_real_concrete_instance_class(self):
+        return ContentType.objects.get_for_model(self.get_real_instance_class(), for_concrete_model=True).model_class()
+
     def get_real_instance(self):
         """Normally not needed.
         If a non-polymorphic manager (like base_objects) has been used to

polymorphic/query.py

@@ -17,6 +17,22 @@ from django.db.models.query import CHUNK_SIZE               # this is 100 for Dj
 Polymorphic_QuerySet_objects_per_request = CHUNK_SIZE
 
 
+def transmogrify(cls, obj):
+    """
+    Upcast a class to a different type without asking questions.
+    """
+    if not '__init__' in obj.__dict__:
+        # Just assign __class__ to a different value.
+        new = obj
+        new.__class__ = cls
+    else:
+        # Run constructor, reassign values
+        new = cls()
+        for k,v in obj.__dict__.items():
+            new.__dict__[k] = v
+    return new
+
+
 ###################################################################################
 ### PolymorphicQuerySet
 
@@ -135,25 +151,31 @@ class PolymorphicQuerySet(QuerySet):
         # - also record the correct result order in "ordered_id_list"
         # - store objects that already have the correct class into "results"
         base_result_objects_by_id = {}
-        self_model_content_type_id = ContentType.objects.get_for_model(self.model).pk
+        self_model_class_id = ContentType.objects.get_for_model(self.model, for_concrete_model=False).pk
+        self_concrete_model_class_id = ContentType.objects.get_for_model(self.model, for_concrete_model=True).pk
+
         for base_object in base_result_objects:
             ordered_id_list.append(base_object.pk)
 
             # check if id of the result object occeres more than once - this can happen e.g. with base_objects.extra(tables=...)
-            assert not base_object.pk in base_result_objects_by_id, (
+            if not base_object.pk in base_result_objects_by_id:
-                "django_polymorphic: result objects do not have unique primary keys - model " + unicode(self.model)
+                base_result_objects_by_id[base_object.pk] = base_object
-            )
 
-            base_result_objects_by_id[base_object.pk] = base_object
+                if base_object.polymorphic_ctype_id == self_model_class_id:
+                    # Real class is exactly the same as base class, go straight to results
+                    results[base_object.pk] = base_object
 
-            # this object is not a derived object and already the real instance => store it right away
+                else:
-            if (base_object.polymorphic_ctype_id == self_model_content_type_id):
+                    real_concrete_class = base_object.get_real_instance_class()
-                results[base_object.pk] = base_object
+                    real_concrete_class_id = base_object.get_real_concrete_instance_class_id()
 
-            # this object is derived and its real instance needs to be retrieved
+                    if real_concrete_class_id == self_concrete_model_class_id:
-            # => store it's id into the bin for this model type
+                        # Real and base classes share the same concrete ancestor,
-            else:
+                        # upcast it and put it in the results
-                idlist_per_model[base_object.get_real_instance_class()].append(base_object.pk)
+                        results[base_object.pk] = transmogrify(real_concrete_class, base_object)
+                    else:
+                        real_concrete_class = ContentType.objects.get_for_id(real_concrete_class_id).model_class()
+                        idlist_per_model[real_concrete_class].append(base_object.pk)
 
         # django's automatic ".pk" field does not always work correctly for
         # custom fields in derived objects (unclear yet who to put the blame on).
@@ -169,24 +191,29 @@ class PolymorphicQuerySet(QuerySet):
         # Then we copy the annotate fields from the base objects to the real objects.
         # Then we copy the extra() select fields from the base objects to the real objects.
         # TODO: defer(), only(): support for these would be around here
-        for modelclass, idlist in idlist_per_model.items():
+        for real_concrete_class, idlist in idlist_per_model.items():
-            qs = modelclass.base_objects.filter(pk__in=idlist)  # use pk__in instead ####
+            real_objects = real_concrete_class.base_objects.filter(pk__in=idlist)  # use pk__in instead ####
-            qs.dup_select_related(self)  # copy select related configuration to new qs
+            real_objects.dup_select_related(self)  # copy select related configuration to new qs
 
-            for o in qs:
+            for real_object in real_objects:
-                o_pk = getattr(o, pk_name)
+                o_pk = getattr(real_object, pk_name)
+                real_class = real_object.get_real_instance_class()
+
+                # If the real class is a proxy, upcast it
+                if real_class != real_concrete_class:
+                    real_object = transmogrify(real_class, real_object)
 
                 if self.query.aggregates:
                     for anno_field_name in self.query.aggregates.keys():
                         attr = getattr(base_result_objects_by_id[o_pk], anno_field_name)
-                        setattr(o, anno_field_name, attr)
+                        setattr(real_object, anno_field_name, attr)
 
                 if self.query.extra_select:
                     for select_field_name in self.query.extra_select.keys():
                         attr = getattr(base_result_objects_by_id[o_pk], select_field_name)
-                        setattr(o, select_field_name, attr)
+                        setattr(real_object, select_field_name, attr)
 
-                results[o_pk] = o
+                results[o_pk] = real_object
 
         # re-create correct order and return result list
         resultlist = [results[ordered_id] for ordered_id in ordered_id_list if ordered_id in results]
@@ -194,14 +221,14 @@ class PolymorphicQuerySet(QuerySet):
         # set polymorphic_annotate_names in all objects (currently just used for debugging/printing)
         if self.query.aggregates:
             annotate_names = self.query.aggregates.keys()  # get annotate field list
-            for o in resultlist:
+            for real_object in resultlist:
-                o.polymorphic_annotate_names = annotate_names
+                real_object.polymorphic_annotate_names = annotate_names
 
         # set polymorphic_extra_select_names in all objects (currently just used for debugging/printing)
         if self.query.extra_select:
             extra_select_names = self.query.extra_select.keys()  # get extra select field list
-            for o in resultlist:
+            for real_object in resultlist:
-                o.polymorphic_extra_select_names = extra_select_names
+                real_object.polymorphic_extra_select_names = extra_select_names
 
         return resultlist
 

polymorphic/query_translate.py

@@ -220,7 +220,7 @@ def _create_model_filter_Q(modellist, not_instance_of=False):
             assert False, 'PolymorphicModel: instance_of expects a list of (polymorphic) models or a single (polymorphic) model'
 
     def q_class_with_subclasses(model):
-        q = Q(polymorphic_ctype=ContentType.objects.get_for_model(model))
+        q = Q(polymorphic_ctype=ContentType.objects.get_for_model(model, for_concrete_model=False))
         for subclass in model.__subclasses__():
             q = q | q_class_with_subclasses(subclass)
         return q

polymorphic/tests.py

@@ -196,7 +196,6 @@ class Middle(Top):
 class Bottom(Middle):
     author = models.CharField(max_length=50)
 
-
 class UUIDProject(ShowFieldTypeAndContent, PolymorphicModel):
         uuid_primary_key = UUIDField(primary_key = True)
         topic = models.CharField(max_length = 30)
@@ -213,6 +212,13 @@ class UUIDPlainB(UUIDPlainA):
 class UUIDPlainC(UUIDPlainB):
     field3 = models.CharField(max_length=10)
 
+# base -> proxy
+class ProxyBase(PolymorphicModel):
+    some_data = models.CharField(max_length=128)
+class ProxyChild(ProxyBase):
+    class Meta:
+        proxy = True
+
 # base -> proxy -> real models
 class ProxiedBase(ShowFieldTypeAndContent, PolymorphicModel):
     name = models.CharField(max_length=10)
@@ -686,6 +692,30 @@ class PolymorphicTests(TestCase):
         self.assertIs(type(parent.childmodel_set.my_queryset_foo()), MyManagerQuerySet)
 
 
+    def test_proxy_models(self):
+        # prepare some data
+        for data in ('bleep bloop', 'I am a', 'computer'):
+            ProxyChild.objects.create(some_data=data)
+
+        # this caches ContentType queries so they don't interfere with our query counts later
+        list(ProxyBase.objects.all())
+
+        # one query per concrete class
+        with self.assertNumQueries(1):
+            items = list(ProxyBase.objects.all())
+
+        self.assertIsInstance(items[0], ProxyChild)
+
+
+    def test_content_types_for_proxy_models(self):
+        """Checks if ContentType is capable of returning proxy models."""
+        from django.db.models import Model
+        from django.contrib.contenttypes.models import ContentType
+
+        ct = ContentType.objects.get_for_model(ProxyChild, for_concrete_model=False)
+        self.assertEqual(ProxyChild, ct.model_class())
+
+
     def test_proxy_model_inheritance(self):
         """
         Polymorphic abilities should also work when the base model is a proxy object.