Added Blinker signal support

docs/changelog.rst

@@ -5,6 +5,7 @@ Changelog
 Changes in dev
 ==============
 
+- Added blinker signal support
 - Added query_counter context manager for tests
 - Added DereferenceBaseField - for improved performance in field dereferencing
 - Added optional map_reduce method item_frequencies

docs/guide/index.rst

@@ -11,3 +11,4 @@ User Guide
    document-instances
    querying
    gridfs
+   signals

mongoengine/__init__.py

@@ -6,9 +6,11 @@ import connection
 from connection import *
 import queryset
 from queryset import *
+import signals
+from signals import *
 
 __all__ = (document.__all__ + fields.__all__ + connection.__all__ +
-           queryset.__all__)
+           queryset.__all__ + signals.__all__)
 
 __author__ = 'Harry Marr'
 

mongoengine/signals.py

@@ -1,5 +1,8 @@
 # -*- coding: utf-8 -*-
 
+__all__ = ['pre_init', 'post_init', 'pre_save', 'post_save',
+           'pre_delete', 'post_delete']
+
 signals_available = False
 try:
     from blinker import Namespace