- Simplified the sweep of instrumentation in strategies._register_attribute

- Improved support for MapperProperty objects overriding
that of an inherited mapper for non-concrete
inheritance setups - attribute extensions won't randomly
collide with each other.  [ticket:1488]

- Added AttributeExtension to sqlalchemy.orm.__all__

1 files changed, 58 insertions, 0 deletions

diff --git a/test/orm/test_mapper.py b/test/orm/test_mapper.py
index edde2a756..13913578a 100644
--- a/test/orm/test_mapper.py
+++ b/test/orm/test_mapper.py
@@ -2219,6 +2219,64 @@ class NoLoadTest(_fixtures.FixtureTest):
             )
 
 
+class AttributeExtensionTest(_base.MappedTest):
+    @classmethod
+    def define_tables(cls, metadata):
+        Table('t1', 
+            metadata,
+            Column('id', Integer, primary_key=True),
+            Column('type', String(40)),
+            Column('data', String(50))
+            
+        )
+
+    @testing.resolve_artifact_names
+    def test_cascading_extensions(self):
+        ext_msg = []
+        
+        class Ex1(sa.orm.AttributeExtension):
+            def set(self, state, value, oldvalue, initiator):
+                ext_msg.append("Ex1 %r" % value)
+                return "ex1" + value
+                
+        class Ex2(sa.orm.AttributeExtension):
+            def set(self, state, value, oldvalue, initiator):
+                ext_msg.append("Ex2 %r" % value)
+                return "ex2" + value
+        
+        class A(_base.BasicEntity):
+            pass
+        class B(A):
+            pass
+        class C(B):
+            pass
+            
+        mapper(A, t1, polymorphic_on=t1.c.type, polymorphic_identity='a', properties={
+            'data':column_property(t1.c.data, extension=Ex1())
+        })
+        mapper(B, polymorphic_identity='b', inherits=A)
+        mc = mapper(C, polymorphic_identity='c', inherits=B, properties={
+            'data':column_property(t1.c.data, extension=Ex2())
+        })
+        
+        a1 = A(data='a1')
+        b1 = B(data='b1')
+        c1 = C(data='c1')
+        
+        eq_(a1.data, 'ex1a1')
+        eq_(b1.data, 'ex1b1')
+        eq_(c1.data, 'ex2c1')
+        
+        a1.data = 'a2'
+        b1.data='b2'
+        c1.data = 'c2'
+        eq_(a1.data, 'ex1a2')
+        eq_(b1.data, 'ex1b2')
+        eq_(c1.data, 'ex2c2')
+        
+        eq_(ext_msg, ["Ex1 'a1'", "Ex1 'b1'", "Ex2 'c1'", "Ex1 'a2'", "Ex1 'b2'", "Ex2 'c2'"])
+        
+    
 class MapperExtensionTest(_fixtures.FixtureTest):
     run_inserts = None