- a "collection-holding" InstrumentedAttribute is now identified

by the presence of a "get_collection" method.
- added "get_collection" to DynamicCollectionAttribute so its
treated as a collection.

1 files changed, 4 insertions, 1 deletions

diff --git a/lib/sqlalchemy/orm/dynamic.py b/lib/sqlalchemy/orm/dynamic.py
index fe3628df2..1d4b5f6c9 100644
--- a/lib/sqlalchemy/orm/dynamic.py
+++ b/lib/sqlalchemy/orm/dynamic.py
@@ -21,7 +21,10 @@ class DynamicCollectionAttribute(attributes.InstrumentedAttribute):
         # we have our own AttributeHistory therefore dont need CommittedState
         # instead, we reset the history stored on the attribute
         obj.__dict__[self.key] = CollectionHistory(self, obj)
-    
+
+    def get_collection(self, obj, user_data=None):
+        return self.get_history(obj)._added_items
+        
     def set(self, obj, value, initiator):
         if initiator is self:
             return