Fixed #18399 – Added a way to get ContentTypes for proxy models

Added kwargs for_concrete_model and for_concrete_models to ContentType
methods get_for_model() and get_for_models(). By setting the flag to
False, it is possible to get the contenttype for proxy models.

django/contrib/contenttypes/models.py

@@ -16,20 +16,24 @@ def get_by_natural_key(self, app_label, model):
             self._add_to_cache(self.db, ct)
         return ct
 
-    def _get_opts(self, model):
-        return model._meta.concrete_model._meta
+    def _get_opts(self, model, for_concrete_model):
+        if for_concrete_model:
+            model = model._meta.concrete_model
+        elif model._deferred:
+            model = model._meta.proxy_for_model
+        return model._meta
 
     def _get_from_cache(self, opts):
         key = (opts.app_label, opts.object_name.lower())
         return self.__class__._cache[self.db][key]
 
-    def get_for_model(self, model):
+    def get_for_model(self, model, for_concrete_model=True):
         """
         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 = self._get_opts(model)
+        opts = self._get_opts(model, for_concrete_model)
         try:
             ct = self._get_from_cache(opts)
         except KeyError:
@@ -45,18 +49,19 @@ def get_for_model(self, model):
 
         return ct
 
-    def get_for_models(self, *models):
+    def get_for_models(self, *models, **kwargs):
         """
         Given *models, returns a dictionary mapping {model: content_type}.
         """
+        for_concrete_models = kwargs.pop('for_concrete_models', True)
         # Final results
         results = {}
         # models that aren't already in the cache
         needed_app_labels = set()
         needed_models = set()
         needed_opts = set()
         for model in models:
-            opts = self._get_opts(model)
+            opts = self._get_opts(model, for_concrete_models)
             try:
                 ct = self._get_from_cache(opts)
             except KeyError:

django/contrib/contenttypes/tests.py

@@ -11,6 +11,13 @@
 from django.utils.encoding import smart_str
 
 
+class ConcreteModel(models.Model):
+    name = models.CharField(max_length=10)
+
+class ProxyModel(ConcreteModel):
+    class Meta:
+        proxy = True
+
 class FooWithoutUrl(models.Model):
     """
     Fake model not defining ``get_absolute_url`` for
@@ -114,6 +121,87 @@ def test_get_for_models_full_cache(self):
             FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
         })
 
+    def test_get_for_concrete_model(self):
+        """
+        Make sure the `for_concrete_model` kwarg correctly works
+        with concrete, proxy and deferred models
+        """
+        concrete_model_ct = ContentType.objects.get_for_model(ConcreteModel)
+
+        self.assertEqual(concrete_model_ct,
+            ContentType.objects.get_for_model(ProxyModel))
+
+        self.assertEqual(concrete_model_ct,
+            ContentType.objects.get_for_model(ConcreteModel,
+                                              for_concrete_model=False))
+
+        proxy_model_ct = ContentType.objects.get_for_model(ProxyModel,
+                                                           for_concrete_model=False)
+
+        self.assertNotEqual(concrete_model_ct, proxy_model_ct)
+
+        # Make sure deferred model are correctly handled
+        ConcreteModel.objects.create(name="Concrete")
+        DeferredConcreteModel = ConcreteModel.objects.only('pk').get().__class__
+        DeferredProxyModel = ProxyModel.objects.only('pk').get().__class__
+
+        self.assertEqual(concrete_model_ct,
+            ContentType.objects.get_for_model(DeferredConcreteModel))
+
+        self.assertEqual(concrete_model_ct,
+            ContentType.objects.get_for_model(DeferredConcreteModel,
+                                              for_concrete_model=False))
+
+        self.assertEqual(concrete_model_ct,
+            ContentType.objects.get_for_model(DeferredProxyModel))
+
+        self.assertEqual(proxy_model_ct,
+            ContentType.objects.get_for_model(DeferredProxyModel,
+                                              for_concrete_model=False))
+
+    def test_get_for_concrete_models(self):
+        """
+        Make sure the `for_concrete_models` kwarg correctly works
+        with concrete, proxy and deferred models.
+        """
+        concrete_model_ct = ContentType.objects.get_for_model(ConcreteModel)
+
+        cts = ContentType.objects.get_for_models(ConcreteModel, ProxyModel)
+        self.assertEqual(cts, {
+            ConcreteModel: concrete_model_ct,
+            ProxyModel: concrete_model_ct,
+        })
+
+        proxy_model_ct = ContentType.objects.get_for_model(ProxyModel,
+                                                           for_concrete_model=False)
+        cts = ContentType.objects.get_for_models(ConcreteModel, ProxyModel,
+                                                 for_concrete_models=False)
+        self.assertEqual(cts, {
+            ConcreteModel: concrete_model_ct,
+            ProxyModel: proxy_model_ct,
+        })
+
+        # Make sure deferred model are correctly handled
+        ConcreteModel.objects.create(name="Concrete")
+        DeferredConcreteModel = ConcreteModel.objects.only('pk').get().__class__
+        DeferredProxyModel = ProxyModel.objects.only('pk').get().__class__
+
+        cts = ContentType.objects.get_for_models(DeferredConcreteModel,
+                                                 DeferredProxyModel)
+        self.assertEqual(cts, {
+            DeferredConcreteModel: concrete_model_ct,
+            DeferredProxyModel: concrete_model_ct,
+        })
+
+        cts = ContentType.objects.get_for_models(DeferredConcreteModel,
+                                                 DeferredProxyModel,
+                                                 for_concrete_models=False)
+        self.assertEqual(cts, {
+            DeferredConcreteModel: concrete_model_ct,
+            DeferredProxyModel: proxy_model_ct,
+        })
+
+
     def test_shortcut_view(self):
         """
         Check that the shortcut view (used for the admin "view on site"

docs/ref/contrib/contenttypes.txt

@@ -187,13 +187,13 @@ The ``ContentTypeManager``
         probably won't ever need to call this method yourself; Django will call
         it automatically when it's needed.
 
-    .. method:: get_for_model(model)
+    .. method:: get_for_model(model[, for_concrete_model=True])
 
         Takes either a model class or an instance of a model, and returns the
         :class:`~django.contrib.contenttypes.models.ContentType` instance
         representing that model.
 
-    .. method:: get_for_models(*models)
+    .. method:: get_for_models(*models[, for_concrete_models=True])
 
         Takes a variadic number of model classes, and returns a dictionary
         mapping the model classes to the
@@ -224,6 +224,19 @@ lookup::
 
 .. _generic-relations:
 
+.. versionadded:: 1.5
+
+Prior to Django 1.5 :meth:`~ContentTypeManager.get_for_model()` and 
+:meth:`~ContentTypeManager.get_for_models()` always returned the 
+:class:`~django.contrib.contenttypes.models.ContentType` associated with the 
+concrete model of the specified one(s). That means there was no way to retreive 
+the :class:`~django.contrib.contenttypes.models.ContentType` of a proxy model 
+using those methods. As of Django 1.5 you can now pass a boolean flag – 
+respectively ``for_concrete_model`` and ``for_concrete_models`` – to specify
+wether or not you want to retreive the 
+:class:`~django.contrib.contenttypes.models.ContentType` for the concrete or 
+direct model.
+
 Generic relations
 =================
 

docs/releases/1.5.txt

@@ -69,6 +69,16 @@ To make it easier to deal with javascript templates which collide with Django's
 syntax, you can now use the :ttag:`verbatim` block tag to avoid parsing the
 tag's content.
 
+Retreival of ``ContentType`` instances associated with proxy models
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The methods :meth:`ContentTypeManager.get_for_model() <django.contrib.contenttypes.models.ContentTypeManager.get_for_model()>` 
+and :meth:`ContentTypeManager.get_for_models() <django.contrib.contenttypes.models.ContentTypeManager.get_for_models()>` 
+have a new keyword argument – respectively ``for_concrete_model`` and ``for_concrete_models``. 
+By passing ``False`` using this argument it is now possible to retreive the
+:class:`ContentType <django.contrib.contenttypes.models.ContentType>` 
+associated with proxy models.
+
 Minor features
 ~~~~~~~~~~~~~~