made some changes according to Tom's comments

djangorestframework/resources.py

@@ -7,15 +7,7 @@ from djangorestframework.response import ErrorResponse
 from djangorestframework.serializer import Serializer, _SkipField
 
 
-def bound_resource_required(meth):
-    def _decorated(self, *args, **kwargs):
-        if not self.is_bound():
-            raise Exception("resource needs to be bound") #TODO: what exception?
-        return meth(self, *args, **kwargs)
-    return _decorated
-
-
-class BaseResource(Serializer):
+class BaseResource(object):
     """
     Base class for all Resource classes, which simply defines the interface
     they provide.
@@ -38,13 +30,13 @@ class BaseResource(Serializer):
         Typically raises a :exc:`response.ErrorResponse` with status code 400
         (Bad Request) on failure.
         """
-        return data
+        raise NotImplementedError()
 
     def filter_response(self, obj):
         """
         Given the response content, filter it into a serializable object.
         """
-        return self.serialize(obj)
+        raise NotImplementedError()
 
     def retrieve(self, *args, **kwargs):
         raise NotImplementedError()
@@ -52,15 +44,16 @@ class BaseResource(Serializer):
     def create(self, *args, **kwargs):
         raise NotImplementedError()
 
-    @bound_resource_required
     def update(self, data, *args, **kwargs):
         raise NotImplementedError()
 
-    @bound_resource_required
     def delete(self, *args, **kwargs):
         raise NotImplementedError()
 
-    @bound_resource_required
+    def list(self, *args, **kwargs):
+        # TODO: QuerysetResource instead !?
+        raise NotImplementedError()
+
     def get_url(self):
         raise NotImplementedError()
 
@@ -68,7 +61,7 @@ class BaseResource(Serializer):
         return not self.instance is None
 
 
-class Resource(BaseResource):
+class Resource(BaseResource, Serializer):
     """
     A Resource determines how a python object maps to some serializable data.
     Objects that a resource can act on include plain Python object instances,
@@ -90,6 +83,12 @@ class Resource(BaseResource):
     # you should explicitly set the fields attribute on your class.
     fields = None
 
+    def validate_request(self, data, files=None):
+        return data
+
+    def filter_response(self, obj):
+        return self.serialize(obj)
+
 
 class FormResource(Resource):
     """
@@ -354,8 +353,12 @@ class ModelResource(FormResource):
         self.instance.save()
         return self.instance
 
-    @bound_resource_required
     def update(self, data, *args, **kwargs):
+        # The resource needs to be bound to an
+        # instance, or updating is not possible
+        if not self.is_bound():
+            raise Exception("resource needs to be bound") #TODO: what exception?
+
         model = self.get_model()
         kwargs = self._clean_url_kwargs(kwargs)
         data = dict(data, **kwargs)
@@ -389,8 +392,12 @@ class ModelResource(FormResource):
         self.instance.save()
         return self.instance
 
-    @bound_resource_required
     def delete(self, *args, **kwargs):
+        # The resource needs to be bound to an
+        # instance, or updating is not possible
+        if not self.is_bound():
+            raise Exception("resource needs to be bound") #TODO: what exception?
+
         self.instance.delete()
         return self.instance
 
@@ -404,7 +411,6 @@ class ModelResource(FormResource):
             queryset = queryset.order_by(ordering)
         return queryset.filter(**kwargs)
 
-    @bound_resource_required
     def get_url(self):
         """
         Attempts to reverse resolve the url of the given model *instance* for
@@ -416,6 +422,8 @@ class ModelResource(FormResource):
         This method can be overridden if you need to set the resource url
         reversing explicitly.
         """
+        if not self.is_bound():
+            raise Exception("resource needs to be bound") #TODO: what exception?
 
         if not hasattr(self, 'view_callable'):
             raise _SkipField