Remove `filter_backend`.

Closes #1775.

1 files changed, 1 insertions, 19 deletions

diff --git a/rest_framework/generics.py b/rest_framework/generics.py
index a6f68657..8bacf470 100644
--- a/rest_framework/generics.py
+++ b/rest_framework/generics.py
@@ -83,7 +83,6 @@ 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):
         """
@@ -191,24 +190,7 @@ class GenericAPIView(views.APIView):
         """
         Returns the list of filter backends that this view requires.
         """
-        if self.filter_backends is None:
-            filter_backends = []
-        else:
-            # Note that we are returning a *copy* of the class attribute,
-            # so that it is safe for the view to mutate it if needed.
-            filter_backends = list(self.filter_backends)
-
-        if not filter_backends and self.filter_backend:
-            warnings.warn(
-                'The `filter_backend` attribute and `FILTER_BACKEND` setting '
-                'are deprecated in favor of a `filter_backends` '
-                'attribute and `DEFAULT_FILTER_BACKENDS` setting, that take '
-                'a *list* of filter backend classes.',
-                DeprecationWarning, stacklevel=2
-            )
-            filter_backends = [self.filter_backend]
-
-        return filter_backends
+        return list(self.filter_backends)
 
     # The following methods provide default implementations
     # that you may want to override for more complex cases.