Added a `post_save` hook. Closes #558.

2 files changed, 22 insertions, 6 deletions

diff --git a/rest_framework/generics.py b/rest_framework/generics.py
index 34e32da3..5abb915b 100644
--- a/rest_framework/generics.py
+++ b/rest_framework/generics.py
@@ -48,7 +48,7 @@ class GenericAPIView(views.APIView):
         return serializer_class
 
     def get_serializer(self, instance=None, data=None,
-                       files=None, partial=False, many=False):
+                       files=None, many=False, partial=False):
         """
         Return the serializer instance that should be used for validating and
         deserializing input, and for serializing output.
@@ -58,6 +58,20 @@ class GenericAPIView(views.APIView):
         return serializer_class(instance, data=data, files=files,
                                 many=many, partial=partial, context=context)
 
+    def pre_save(self, obj):
+        """
+        Placeholder method for calling before saving an object.
+        May be used eg. to set attributes on the object that are implicit
+        in either the request, or the url.
+        """
+        pass
+
+    def post_save(self, obj, created=False):
+        """
+        Placeholder method for calling after saving an object.
+        """
+        pass
+
 
 class MultipleObjectAPIView(MultipleObjectMixin, GenericAPIView):
     """
diff --git a/rest_framework/mixins.py b/rest_framework/mixins.py
index 73a3d200..61ac225b 100644
--- a/rest_framework/mixins.py
+++ b/rest_framework/mixins.py
@@ -22,6 +22,7 @@ class CreateModelMixin(object):
         if serializer.is_valid():
             self.pre_save(serializer.object)
             self.object = serializer.save()
+            self.post_save(self.object, created=True)
             headers = self.get_success_headers(serializer.data)
             return Response(serializer.data, status=status.HTTP_201_CREATED,
                             headers=headers)
@@ -34,9 +35,6 @@ class CreateModelMixin(object):
         except (TypeError, KeyError):
             return {}
 
-    def pre_save(self, obj):
-        pass
-
 
 class ListModelMixin(object):
     """
@@ -88,12 +86,15 @@ class UpdateModelMixin(object):
     """
     def update(self, request, *args, **kwargs):
         partial = kwargs.pop('partial', False)
+        self.object = None
         try:
             self.object = self.get_object()
-            success_status_code = status.HTTP_200_OK
         except Http404:
-            self.object = None
+            created = True
             success_status_code = status.HTTP_201_CREATED
+        else:
+            created = False
+            success_status_code = status.HTTP_200_OK
 
         serializer = self.get_serializer(self.object, data=request.DATA,
                                          files=request.FILES, partial=partial)
@@ -101,6 +102,7 @@ class UpdateModelMixin(object):
         if serializer.is_valid():
             self.pre_save(serializer.object)
             self.object = serializer.save()
+            self.post_save(self.object, created=created)
             return Response(serializer.data, status=success_status_code)
 
         return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)