- the enable_typechecks=False setting on relation()

now only allows subtypes with inheriting mappers.
Totally unrelated types, or subtypes not set up with
mapper inheritance against the target mapper are
still not allowed.

diff --git a/CHANGES b/CHANGES
index ec85febbb518506ef37379bdef337c8899bf321f..7f9d208b9e422f28561414ace494984af91cd004 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -15,6 +15,12 @@ CHANGES
     - Query.count() will take single-table inheritance
       subtypes into account the same way row-based
       results do. [ticket:1008]
+
+    - the enable_typechecks=False setting on relation()
+      now only allows subtypes with inheriting mappers.  
+      Totally unrelated types, or subtypes not set up with
+      mapper inheritance against the target mapper are 
+      still not allowed.
       
 - mysql
     - Added 'CALL' to the list of SQL keywords which return

diff --git a/lib/sqlalchemy/orm/dependency.py b/lib/sqlalchemy/orm/dependency.py
index c667460a71796bece5c567ab23a36b95dc0e674c..c16bd8bbd00f5bec2aec8f49fcee0bbe3cbf793e 100644 (file)
--- a/lib/sqlalchemy/orm/dependency.py
+++ b/lib/sqlalchemy/orm/dependency.py
@@ -108,11 +108,12 @@ class DependencyProcessor(object):
         raise NotImplementedError()
 
     def _verify_canload(self, state):
-        if not self.enable_typechecks:
-            return
-        if state is not None and not self.mapper._canload(state):
-            raise exceptions.FlushError("Attempting to flush an item of type %s on collection '%s', which is handled by mapper '%s' and does not load items of that type.  Did you mean to use a polymorphic mapper for this relationship ?  Set 'enable_typechecks=False' on the relation() to disable this exception.  Mismatched typeloading may cause bi-directional relationships (backrefs) to not function properly." % (state.class_, self.prop, self.mapper))
-
+        if state is not None and not self.mapper._canload(state, allow_subtypes=not self.enable_typechecks):
+            if self.mapper._canload(state, allow_subtypes=True):
+                raise exceptions.FlushError("Attempting to flush an item of type %s on collection '%s', which is not the expected type %s.  Configure mapper '%s' to load this subtype polymorphically, or set enable_typechecks=False to allow subtypes.  Mismatched typeloading may cause bi-directional relationships (backrefs) to not function properly." % (state.class_, self.prop, self.mapper.class_, self.mapper))
+            else:
+                raise exceptions.FlushError("Attempting to flush an item of type %s on collection '%s', whose mapper does not inherit from that of %s." % (state.class_, self.prop, self.mapper.class_))
+            
     def _synchronize(self, state, child, associationrow, clearkeys, uowcommit):
         """Called during a flush to synchronize primary key identifier
         values between a parent/child object, as well as to an

diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py
index 448d797d06440bc8c2831703760c908253b31c85..d39e743e017f6c15b7c009b1fbbc680cc3f33564 100644 (file)
--- a/lib/sqlalchemy/orm/mapper.py
+++ b/lib/sqlalchemy/orm/mapper.py
@@ -945,9 +945,9 @@ class Mapper(object):
     def _primary_key_from_state(self, state):
         return [self._get_state_attr_by_column(state, column) for column in self.primary_key]
 
-    def _canload(self, state):
-        if self.polymorphic_on:
-            return issubclass(state.class_, self.class_)
+    def _canload(self, state, allow_subtypes):
+        if self.polymorphic_on or allow_subtypes:
+            return self.isa(_state_mapper(state))
         else:
             return state.class_ is self.class_
 

diff --git a/test/orm/relationships.py b/test/orm/relationships.py
index 40773f8359599013eaa697bf45996a146d257cea..de3028903eedda7ecc5ab985de9ffc449c0a91d4 100644 (file)
--- a/test/orm/relationships.py
+++ b/test/orm/relationships.py
@@ -646,11 +646,8 @@ class TypeMatchTest(ORMTest):
         sess.save(a1)
         sess.save(b1)
         sess.save(c1)
-        try:
-            sess.flush()
-            assert False
-        except exceptions.FlushError, err:
-            assert str(err).startswith("Attempting to flush an item of type %s on collection 'A.bs (B)', which is handled by mapper 'Mapper|B|b' and does not load items of that type.  Did you mean to use a polymorphic mapper for this relationship ?" % C)
+        self.assertRaises(exceptions.FlushError, sess.flush)
+
     def test_o2m_nopoly_onflush(self):
         class A(object):pass
         class B(object):pass
@@ -668,11 +665,7 @@ class TypeMatchTest(ORMTest):
         sess.save(a1)
         sess.save(b1)
         sess.save(c1)
-        try:
-            sess.flush()
-            assert False
-        except exceptions.FlushError, err:
-            assert str(err).startswith("Attempting to flush an item of type %s on collection 'A.bs (B)', which is handled by mapper 'Mapper|B|b' and does not load items of that type.  Did you mean to use a polymorphic mapper for this relationship ?" % C)
+        self.assertRaises(exceptions.FlushError, sess.flush)
 
     def test_m2o_nopoly_onflush(self):
         class A(object):pass
@@ -687,11 +680,8 @@ class TypeMatchTest(ORMTest):
         sess = create_session()
         sess.save(b1)
         sess.save(d1)
-        try:
-            sess.flush()
-            assert False
-        except exceptions.FlushError, err:
-            assert str(err).startswith("Attempting to flush an item of type %s on collection 'D.a (A)', which is handled by mapper 'Mapper|A|a' and does not load items of that type.  Did you mean to use a polymorphic mapper for this relationship ?" % B)
+        self.assertRaises(exceptions.FlushError, sess.flush)
+
     def test_m2o_oncascade(self):
         class A(object):pass
         class B(object):pass
@@ -703,6 +693,7 @@ class TypeMatchTest(ORMTest):
         d1 = D()
         d1.a = b1
         sess = create_session()
+
         try:
             sess.save(d1)
             assert False