# HG changeset patch
# User btimby
# Date 1328412499 0
# Node ID d4563cb0376c8b0cb207e28422e07e73cc0abb13
# Parent  2b46eceda739921c2ef9d034ea86729bc2c6722e
Handle importing valid module name as backend when that module is NOT a backend.

diff -r 2b46eceda739 -r d4563cb0376c queues/__init__.py
--- a/queues/__init__.py	Sun Feb 05 03:10:46 2012 +0000
+++ b/queues/__init__.py	Sun Feb 05 03:28:19 2012 +0000
@@ -56,3 +56,8 @@
         queues = __import__(BACKEND, {}, {}, [''])
     except ImportError:
         raise InvalidBackend("Unable to import QUEUE BACKEND '%s'" % BACKEND)
+    # Check that this is really a queues backend, not just some other random
+    # module.
+    from .backends.base import BaseQueue
+    if not getattr(queues, 'Queue', None) in BaseQueue.__subclasses__():
+        raise InvalidBackend("Unable to import QUEUE_BACKEND '%s' does not appear to be valid." % BACKEND)
diff -r 2b46eceda739 -r d4563cb0376c queues/backends/__init__.py
--- a/queues/backends/__init__.py	Sun Feb 05 03:10:46 2012 +0000
+++ b/queues/backends/__init__.py	Sun Feb 05 03:28:19 2012 +0000
@@ -25,3 +25,6 @@
         backend = __import__(BACKEND, {}, {}, [''])
     except ImportError:
         raise InvalidBackend("Unable to import QUEUE BACKEND '%s'" % BACKEND)
+    from .base import BaseQueue
+    if not getattr(backend, 'Queue', None) in BaseQueue.__subclasses__():
+        raise InvalidBackend("Unable to import QUEUE BACKEND '%s' does not appear to be valid." % BACKEND)