From 612c4f80313363a0aff787310a0d31b37c9d6fc6 Mon Sep 17 00:00:00 2001
From: Brandon Taylor <alsoicode@gmail.com>
Date: Mon, 3 Nov 2014 10:43:41 -0500
Subject: [PATCH] Added method to check for self-referential sortable foreign
 keys.

---
 adminsortable/utils.py | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/adminsortable/utils.py b/adminsortable/utils.py
index c858f88..82141d9 100644
--- a/adminsortable/utils.py
+++ b/adminsortable/utils.py
@@ -1,4 +1,4 @@
-from .models import Sortable
+from .models import Sortable, SortableForeignKey
 
 
 def get_is_sortable(objects):
@@ -9,9 +9,22 @@ def get_is_sortable(objects):
     return False
 
 
+def is_self_referential(cls):
+    cls_type = type(cls)
+    sortable_subclass = issubclass(cls_type, Sortable)
+    sortable_foreign_key_subclass = issubclass(cls_type, SortableForeignKey)
+    if sortable_foreign_key_subclass and not sortable_subclass:
+        return True
+    return False
+
+
 def check_model_is_sortable(cls):
     if cls:
-        if issubclass(type(cls), Sortable):
-            if cls.objects.count() > 1:
-                return True
+        if is_self_referential(cls):
+            objects = cls.model.objects
+        else:
+            objects = cls.objects
+
+        if objects.count() > 1:
+            return True
     return False