Add common.utils.return_related function to support double underscore related model references.

Signed-off-by: Michael Price <loneviking72@gmail.com>

mayan/apps/acls/managers.py

@@ -8,7 +8,7 @@ from django.db import models
 from django.db.models import Q
 from django.utils.translation import ugettext, ugettext_lazy as _
 
-from common.utils import return_attrib
+from common.utils import return_attrib, return_related
 from permissions import Permission
 from permissions.models import StoredPermission
 
@@ -115,7 +115,7 @@ class AccessControlListManager(models.Manager):
             else:
                 instance = queryset.first()
                 if instance:
-                    parent_object = getattr(instance, parent_accessor)
+                    parent_object = return_related(instance, parent_accessor)
 
                     try:
                         # Try to see if parent_object is a function

mayan/apps/common/utils.py

@@ -149,6 +149,15 @@ def return_attrib(obj, attrib, arguments=None):
             return force_text(exception)
 
 
+def return_related(instance, attribute):
+    """
+    This functions works in a similar method to return_attrib but is
+    meant for related models. Support multiple levels of relationship
+    using double underscore.
+    """
+    return reduce_function(getattr, attribute.split('__'), instance)
+
+
 def urlquote(link=None, get=None):
     """
     This method does both: urlquote() and urlencode()