Merge pull request #120 from postatum/fix_eventinstance

Check for DataProxy when setting event.instance

docs/source/field_processors.rst

@@ -28,7 +28,7 @@ Keyword Arguments
     New value of of field
 
 **instance**
-    Instance affected by request. Is None when set of items is updated in bulk and when item is created.
+    Instance affected by request. Is None when set of items is updated in bulk and when item is created. ``event.response`` may be used to access newly created object, if object is returned by view method.
 
 **field**
     Instance of nefertari.utils.data.FieldData instance containing data of changed field.

nefertari/events.py

@@ -1,6 +1,6 @@
 from contextlib import contextmanager
 
-from nefertari.utils import FieldData
+from nefertari.utils import FieldData, DataProxy
 
 
 class RequestEvent(object):
@@ -19,16 +19,25 @@ class RequestEvent(object):
         determine what event was triggered when same event handler was
         registered with and without field predicate.
     :param instance: Object instance affected by request. Used in item
-        requests  only. Should be used to read data only. Changes to the
-        instance may result in database data inconsistency.
+        requests  only(item GET, PATCH, PUT, DELETE). Should be used
+        to read data only. Changes to the instance may result in database
+        data inconsistency.
+    :param response: Return value of view method. E.g. if view method
+        returns "1", value of event.response will be "1". Is None in all
+        "before" events. Note that is not necessarily a valid Pyramid
+        Response instance but the exact value returned by view method.
+        May be useful to access newly created object on "create" action
+        if it is returned by view method.
     """
     def __init__(self, model, view,
-                 fields=None, field=None, instance=None):
+                 fields=None, field=None, instance=None,
+                 response=None):
         self.model = model
         self.view = view
         self.fields = fields
         self.field = field
         self.instance = instance
+        self.response = response
 
     def set_field_value(self, field_name, value):
         """ Set value of field named `field_name`.
@@ -287,15 +296,17 @@ def trigger_events(view_obj):
                 view_obj._json_params,
                 view_obj.Model)
         }
-        if hasattr(view_obj.context, 'pk_field'):
-            event_kwargs['instance'] = view_obj.context
+        ctx = view_obj.context
+        if hasattr(ctx, 'pk_field') or isinstance(ctx, DataProxy):
+            event_kwargs['instance'] = ctx
 
         before_event = BEFORE_EVENTS[event_action]
         request.registry.notify(before_event(**event_kwargs))
 
     yield
 
     if do_trigger:
+        event_kwargs['response'] = view_obj._response
         after_event = AFTER_EVENTS[event_action]
         request.registry.notify(after_event(**event_kwargs))
 

nefertari/view.py

@@ -62,7 +62,8 @@ def view_mapper_wrapper(context, request):
                 raise JHTTPNotFound()
 
             with trigger_events(view_obj):
-                return action(**matchdict)
+                view_obj._response = action(**matchdict)
+                return view_obj._response
 
         return view_mapper_wrapper
 

tests/test_events.py

@@ -58,7 +58,7 @@ def test_trigger_events(self, mock_from):
 
         mock_after.assert_called_once_with(
             fields={'foo': 1}, model=view.Model, instance=ctx,
-            view=view)
+            view=view, response=view._response)
         mock_before.assert_called_once_with(
             fields={'foo': 1}, model=view.Model, instance=ctx,
             view=view)
@@ -146,7 +146,8 @@ class A(object):
                     pass
 
         mock_after.assert_called_once_with(
-            fields={'foo': 1}, model=view.Model, view=view)
+            fields={'foo': 1}, model=view.Model, view=view,
+            response=view._response)
         mock_before.assert_called_once_with(
             fields={'foo': 1}, model=view.Model, view=view)
         view.request.registry.notify.assert_has_calls([

tests/test_view.py

@@ -52,6 +52,7 @@ def test_viewmapper(self):
 
         class MyView(object):
             Model = Mock
+            _response = None
 
             def __init__(self, ctx, req):
                 self._before_calls = {'index': [bc1], 'show': [bc3]}