Minor tweaks to internals of generics and mixins

rest_framework/generics.py

@@ -66,9 +66,6 @@ class MultipleObjectAPIView(MultipleObjectMixin, GenericAPIView):
         backend = self.filter_backend()
         return backend.filter_queryset(self.request, queryset, self)
 
-    def get_filtered_queryset(self):
-        return self.filter_queryset(self.get_queryset())
-
     def get_pagination_serializer_class(self):
         """
         Return the class to use for the pagination serializer.

rest_framework/mixins.py

@@ -24,9 +24,9 @@ class CreateModelMixin(object):
         return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)
 
     def get_success_headers(self, data):
-        if 'url' in data:
-            return {'Location': data.get('url')}
-        else:
+        try:
+            return {'Location': data['url']}
+        except (TypeError, KeyError):
             return {}
 
     def pre_save(self, obj):
@@ -41,14 +41,16 @@ class ListModelMixin(object):
     empty_error = u"Empty list and '%(class_name)s.allow_empty' is False."
 
     def list(self, request, *args, **kwargs):
-        self.object_list = self.get_filtered_queryset()
+        queryset = self.get_queryset()
+        self.object_list = self.filter_queryset(queryset)
 
         # Default is to allow empty querysets.  This can be altered by setting
         # `.allow_empty = False`, to raise 404 errors on empty querysets.
         allow_empty = self.get_allow_empty()
-        if not allow_empty and len(self.object_list) == 0:
-            error_args = {'class_name': self.__class__.__name__}
-            raise Http404(self.empty_error % error_args)
+        if not allow_empty and not self.object_list:
+            class_name = self.__class__.__name__
+            error_msg = self.empty_error % {'class_name': class_name}
+            raise Http404(error_msg)
 
         # Pagination size is set by the `.paginate_by` attribute,
         # which may be `None` to disable pagination.
@@ -82,17 +84,18 @@ class UpdateModelMixin(object):
     def update(self, request, *args, **kwargs):
         try:
             self.object = self.get_object()
-            success_status = status.HTTP_200_OK
+            created = False
         except Http404:
             self.object = None
-            success_status = status.HTTP_201_CREATED
+            created = True
 
         serializer = self.get_serializer(self.object, data=request.DATA)
 
         if serializer.is_valid():
             self.pre_save(serializer.object)
             self.object = serializer.save()
-            return Response(serializer.data, status=success_status)
+            status_code = created and status.HTTP_201_CREATED or status.HTTP_200_OK
+            return Response(serializer.data, status=status_code)
 
         return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)