Support for multiple filter classes

2 files changed, 26 insertions, 9 deletions

diff --git a/rest_framework/generics.py b/rest_framework/generics.py
index 2bb23a89..05ec93d3 100644
--- a/rest_framework/generics.py
+++ b/rest_framework/generics.py
@@ -39,8 +39,8 @@ class GenericAPIView(views.APIView):
     pagination_serializer_class = api_settings.DEFAULT_PAGINATION_SERIALIZER_CLASS
     page_kwarg = 'page'
 
-    # The filter backend class to use for queryset filtering
-    filter_backend = api_settings.FILTER_BACKEND
+    # The filter backend classes to use for queryset filtering
+    filter_backends = api_settings.DEFAULT_FILTER_BACKENDS
 
     # The following attributes may be subject to change,
     # and should be considered private API.
@@ -54,6 +54,7 @@ class GenericAPIView(views.APIView):
     slug_url_kwarg = 'slug'
     slug_field = 'slug'
     allow_empty = True
+    filter_backend = api_settings.FILTER_BACKEND
 
     def get_serializer_context(self):
         """
@@ -150,10 +151,20 @@ class GenericAPIView(views.APIView):
         method if you want to apply the configured filtering backend to the
         default queryset.
         """
-        if not self.filter_backend:
-            return queryset
-        backend = self.filter_backend()
-        return backend.filter_queryset(self.request, queryset, self)
+        filter_backends = self.filter_backends or []
+        if not filter_backends and self.filter_backend:
+            warnings.warn(
+                'The `filter_backend` attribute and `FILTER_BACKEND` setting '
+                'are due to be deprecated in favor of a `filter_backends` '
+                'attribute and `DEFAULT_FILTER_BACKENDS` setting, that take '
+                'a *list* of filter backend classes.',
+                PendingDeprecationWarning, stacklevel=2
+            )
+            filter_backends = [self.filter_backend]
+
+        for backend in filter_backends:
+            queryset = backend().filter_queryset(self.request, queryset, self)
+        return queryset
 
     ########################
     ### The following methods provide default implementations
diff --git a/rest_framework/settings.py b/rest_framework/settings.py
index eede0c5a..734d8478 100644
--- a/rest_framework/settings.py
+++ b/rest_framework/settings.py
@@ -29,6 +29,7 @@ from rest_framework.compat import six
 USER_SETTINGS = getattr(settings, 'REST_FRAMEWORK', None)
 
 DEFAULTS = {
+    # Base API policies
     'DEFAULT_RENDERER_CLASSES': (
         'rest_framework.renderers.JSONRenderer',
         'rest_framework.renderers.BrowsableAPIRenderer',
@@ -50,11 +51,15 @@ DEFAULTS = {
 
     'DEFAULT_CONTENT_NEGOTIATION_CLASS':
         'rest_framework.negotiation.DefaultContentNegotiation',
+
+    # Genric view behavior
     'DEFAULT_MODEL_SERIALIZER_CLASS':
         'rest_framework.serializers.ModelSerializer',
     'DEFAULT_PAGINATION_SERIALIZER_CLASS':
         'rest_framework.pagination.PaginationSerializer',
+    'DEFAULT_FILTER_BACKENDS': (),
 
+    # Throttling
     'DEFAULT_THROTTLE_RATES': {
         'user': None,
         'anon': None,
@@ -64,9 +69,6 @@ DEFAULTS = {
     'PAGINATE_BY': None,
     'PAGINATE_BY_PARAM': None,
 
-    # Filtering
-    'FILTER_BACKEND': None,
-
     # Authentication
     'UNAUTHENTICATED_USER': 'django.contrib.auth.models.AnonymousUser',
     'UNAUTHENTICATED_TOKEN': None,
@@ -95,6 +97,9 @@ DEFAULTS = {
         ISO_8601,
     ),
     'TIME_FORMAT': ISO_8601,
+
+    # Pending deprecation
+    'FILTER_BACKEND': None,
 }
 
 
@@ -108,6 +113,7 @@ IMPORT_STRINGS = (
     'DEFAULT_CONTENT_NEGOTIATION_CLASS',
     'DEFAULT_MODEL_SERIALIZER_CLASS',
     'DEFAULT_PAGINATION_SERIALIZER_CLASS',
+    'DEFAULT_FILTER_BACKENDS',
     'FILTER_BACKEND',
     'UNAUTHENTICATED_USER',
     'UNAUTHENTICATED_TOKEN',