Retry form rendering when rendering with serializer fails.

rest_framework/renderers.py

@@ -473,32 +473,40 @@ def get_rendered_html_form(self, data, view, method, request):
             ):
                 return
 
+            serializers = []
             if existing_serializer is not None:
-                serializer = existing_serializer
+                serializers.append(existing_serializer)
+
+            if has_serializer:
+                if method in ('PUT', 'PATCH'):
+                    serializers.append(view.get_serializer(instance=instance, **kwargs))
+                else:
+                    serializers.append(view.get_serializer(**kwargs))
             else:
-                if has_serializer:
-                    if method in ('PUT', 'PATCH'):
-                        serializer = view.get_serializer(instance=instance, **kwargs)
-                    else:
-                        serializer = view.get_serializer(**kwargs)
+                # at this point we must have a serializer_class
+                if method in ('PUT', 'PATCH'):
+                    serializers.append(self._get_serializer(view.serializer_class, view,
+                                                            request, instance=instance, **kwargs))
                 else:
-                    # at this point we must have a serializer_class
-                    if method in ('PUT', 'PATCH'):
-                        serializer = self._get_serializer(view.serializer_class, view,
-                                                          request, instance=instance, **kwargs)
-                    else:
-                        serializer = self._get_serializer(view.serializer_class, view,
-                                                          request, **kwargs)
-
-            if hasattr(serializer, 'initial_data'):
-                serializer.is_valid()
-
-            form_renderer = self.form_renderer_class()
-            return form_renderer.render(
-                serializer.data,
-                self.accepted_media_type,
-                {'style': {'template_pack': 'rest_framework/horizontal'}}
-            )
+                    serializers.append(self._get_serializer(view.serializer_class, view,
+                                                            request, **kwargs))
+
+            for serializer in serializers:
+                try:
+                    if hasattr(serializer, 'initial_data'):
+                        serializer.is_valid()
+
+                    form_renderer = self.form_renderer_class()
+                    return form_renderer.render(
+                        serializer.data,
+                        self.accepted_media_type,
+                        {'style': {'template_pack': 'rest_framework/horizontal'}}
+                    )
+                except TypeError:
+                    pass
+            # If none of the rendering attempts succeeded, raise the TypeError generated by the last
+            # attempt.
+            raise
 
     def get_raw_data_form(self, data, view, method, request):
         """

tests/test_generics.py

@@ -64,6 +64,16 @@ class FKInstanceView(generics.RetrieveUpdateDestroyAPIView):
     serializer_class = ForeignKeySerializer
 
 
+class ManyPostView(generics.GenericAPIView):
+    queryset = BasicModel.objects.all()
+    serializer_class = BasicSerializer
+    renderer_classes = (renderers.BrowsableAPIRenderer, renderers.JSONRenderer)
+
+    def post(self, request, *args, **kwargs):
+        serializer = self.get_serializer(self.get_queryset(), many=True)
+        return Response(serializer.data, status.HTTP_200_OK)
+
+
 class SlugBasedInstanceView(InstanceView):
     """
     A model with a slug-field.
@@ -542,3 +552,30 @@ def get(self, request):
         request = factory.get('/')
         with pytest.raises(RuntimeError):
             view(request).render()
+
+
+class TestManyPostView(TestCase):
+    def setUp(self):
+        """
+        Create 3 BasicModel instances.
+        """
+        items = ['foo', 'bar', 'baz']
+        for item in items:
+            BasicModel(text=item).save()
+        self.objects = BasicModel.objects
+        self.data = [
+            {'id': obj.id, 'text': obj.text}
+            for obj in self.objects.all()
+        ]
+        self.view = ManyPostView.as_view()
+
+    def test_post_many_post_view(self):
+        """
+        POST request to ManyPostView should return a list of objects.
+        """
+        data = {}
+        request = factory.post('/', data, format='json')
+        with self.assertNumQueries(1):
+            response = self.view(request).render()
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(len(response.data), 3)