- add instrumentation events

- simplify listen_for_events example with new system
- add "propagate", "retval", "raw" flags to attribute events.  this solves the "return value"
issue as well as the "subclass" issue.
- begin thinking about event removal.   Each listen() method will have a corresponding remove().
Custom listen() methods will have to package all the info onto the event function that is needed
to remove its state.

1 files changed, 6 insertions, 4 deletions

diff --git a/lib/sqlalchemy/orm/deprecated_interfaces.py b/lib/sqlalchemy/orm/deprecated_interfaces.py
index fc5a74a32..86f6ed74e 100644
--- a/lib/sqlalchemy/orm/deprecated_interfaces.py
+++ b/lib/sqlalchemy/orm/deprecated_interfaces.py
@@ -385,12 +385,14 @@ class AttributeExtension(object):
     @classmethod
     def _adapt_listener(cls, self, listener):
         event.listen(listener.append, 'on_append', self,
-                            active_history=listener.active_history)
+                            active_history=listener.active_history,
+                            raw=True, retval=True)
         event.listen(listener.remove, 'on_remove', self,
-                            active_history=listener.active_history)
+                            active_history=listener.active_history, 
+                            raw=True, retval=True)
         event.listen(listener.set, 'on_set', self,
-                            active_history=listener.active_history)
-        
+                            active_history=listener.active_history, 
+                            raw=True, retval=True)
     
     def append(self, state, value, initiator):
         """Receive a collection append event.