Fixed reload issue with ReferenceField where dbref=False (MongoEngine/mongoengine#138)

docs/changelog.rst

@@ -2,6 +2,10 @@
 Changelog
 =========
 
+Changes in 0.7.X
+================
+- Fixed reload issue with ReferenceField where dbref=False (MongoEngine/mongoengine#138)
+
 Changes in 0.7.5
 ================
 - ReferenceFields with dbref=False use ObjectId instead of strings (MongoEngine/mongoengine#134)

mongoengine/dereference.py

@@ -31,10 +31,10 @@ class DeReference(object):
             items = [i for i in items]
 
         self.max_depth = max_depth
-
         doc_type = None
+
         if instance and instance._fields:
-            doc_type = instance._fields[name]
+            doc_type = instance._fields.get(name)
             if hasattr(doc_type, 'field'):
                 doc_type = doc_type.field
 
@@ -166,7 +166,7 @@ class DeReference(object):
                 return self.object_map.get(items['_ref'].id, items)
             elif '_types' in items and '_cls' in items:
                 doc = get_document(items['_cls'])._from_son(items)
-                doc._data = self._attach_objects(doc._data, depth, doc, name)
+                doc._data = self._attach_objects(doc._data, depth, doc, None)
                 return doc
 
         if not hasattr(items, 'items'):

mongoengine/document.py

@@ -361,7 +361,12 @@ class Document(BaseDocument):
         id_field = self._meta['id_field']
         obj = self.__class__.objects(
                 **{id_field: self[id_field]}
-              ).first().select_related(max_depth=max_depth)
+              ).limit(1).select_related(max_depth=max_depth)
+        if obj:
+            obj = obj[0]
+        else:
+            msg = "Reloaded document has been deleted"
+            raise OperationError(msg)
         for field in self._fields:
             setattr(self, field, self._reload(field, obj[field]))
         if self._dynamic:

tests/test_dereference.py

@@ -84,6 +84,7 @@ class FieldTest(unittest.TestCase):
 
         group = Group(members=User.objects)
         group.save()
+        group.reload()  # Confirm reload works
 
         with query_counter() as q:
             self.assertEqual(q, 0)