Microtweak and bwcompat code.

2 files changed, 17 insertions, 2 deletions

diff --git a/repoze/bfg/tests/test_traversal.py b/repoze/bfg/tests/test_traversal.py
index 4782ab264..3b0c4318c 100644
--- a/repoze/bfg/tests/test_traversal.py
+++ b/repoze/bfg/tests/test_traversal.py
@@ -225,6 +225,16 @@ class ModelGraphTraverserTests(unittest.TestCase):
         environ = self._getEnviron(PATH_INFO='/%s' % segment)
         self.assertRaises(TypeError, policy, environ)
 
+    def test_locatable_bwcompat(self):
+        root = DummyContext()
+        from repoze.bfg.interfaces import ILocation
+        from zope.interface import directlyProvides
+        policy = self._makeOne(root)
+        self.assertEqual(policy.locatable, False)
+        directlyProvides(root, ILocation)
+        self.assertEqual(policy.locatable, True)
+
+
 class FindInterfaceTests(unittest.TestCase):
     def _callFUT(self, context, iface):
         from repoze.bfg.traversal import find_interface
diff --git a/repoze/bfg/traversal.py b/repoze/bfg/traversal.py
index 476f119b9..4f1ffb60d 100644
--- a/repoze/bfg/traversal.py
+++ b/repoze/bfg/traversal.py
@@ -221,7 +221,12 @@ class ModelGraphTraverser(object):
     implements(ITraverser)
     def __init__(self, root):
         self.root = root
-        self.locatable = ILocation.providedBy(root)
+
+    @property
+    def locatable(self):
+        """ Backwards compatibility for Malthe and David, even though
+        they're not supposed to be using this ;-)""" 
+        return ILocation.providedBy(self.root)
 
     def __call__(self, environ, _marker=_marker):
         try:
@@ -235,11 +240,11 @@ class ModelGraphTraverser(object):
             pass
             
         path = list(traversal_path(path))
-        locatable = self.locatable
         step = self._step
 
         ob = self.root
         name = ''
+        locatable = ILocation.providedBy(ob)
 
         while path:
             segment = path.pop(0)