added global model registry and GenericReferenceField, a ReferenceField not bound to a particular model

tests/fields.py

@@ -2,6 +2,8 @@ import unittest
 import datetime
 from decimal import Decimal
 
+import pymongo
+
 from mongoengine import *
 from mongoengine.connection import _get_db
 
@@ -348,6 +350,97 @@ class FieldTest(unittest.TestCase):
 
         Member.drop_collection()
         BlogPost.drop_collection()
+        
+    def test_generic_reference(self):
+        """Ensure that a GenericReferenceField properly dereferences 
+        relationships to *any* model.
+        """
+        class Link(Document):
+            title = StringField()
+            
+        class Post(Document):
+            title = StringField()
+            
+        class Bookmark(Document):
+            bookmark_object = GenericReferenceField()
+            
+        Link.drop_collection()
+        Post.drop_collection()
+        Bookmark.drop_collection()
+    
+        link_1 = Link(title="Pitchfork")
+        link_1.save()
+    
+        post_1 = Post(title="Behind the Scenes of the Pavement Reunion")
+        post_1.save()
+        
+        bm = Bookmark(bookmark_object=post_1)
+        bm.save()
+        
+        bm.reload()
+        
+        self.assertEqual(bm.bookmark_object, post_1)
+        
+        bm.bookmark_object = link_1
+        bm.save()
+        
+        bm.reload()
+        
+        self.assertEqual(bm.bookmark_object, link_1)
+    
+        Link.drop_collection()
+        Post.drop_collection()
+        Bookmark.drop_collection()
+
+    # def test_generic_reference_list(self):
+    #     """Ensure that a ListField properly dereferences 
+    #     relationships to *any* model via GenericReferenceField.
+    #     """
+    #     class Link(Document):
+    #         title = StringField()
+    # 
+    #     class Post(Document):
+    #         title = StringField()
+    # 
+    #     class User(Document):
+    #         bookmarks = ListField(GenericReferenceField())
+    # 
+    #     Link.drop_collection()
+    #     Post.drop_collection()
+    #     User.drop_collection()
+    # 
+    #     link_1 = Link(title="Pitchfork")
+    #     link_1.save()
+    # 
+    #     post_1 = Post(title="Behind the Scenes of the Pavement Reunion")
+    #     post_1.save()
+    # 
+    #     user = User(bookmarks=[post_1, link_1])
+    #     user.save()
+    #     
+    #     del user
+    # 
+    #     user = User.objects().first()
+    #     print user.bookmarks
+    #     
+    #     # print dir(user)
+    #     
+    #     # self.assertEqual(bm.bookmark_object, post_1)
+    #     # self.assertEqual(bm._data['bookmark_object'].__class__, 
+    #     #                  pymongo.dbref.DBRef)
+    #     # 
+    #     # bm.bookmark_object = link_1
+    #     # bm.save()
+    #     # 
+    #     # bm.reload()
+    #     # 
+    #     # self.assertEqual(bm.bookmark_object, link_1)
+    #     # self.assertEqual(bm._data['bookmark_object'].__class__, 
+    #     #                  pymongo.dbref.DBRef)
+    # 
+    #     Link.drop_collection()
+    #     Post.drop_collection()
+    #     User.drop_collection()
 
 
 if __name__ == '__main__':