Added support for self refernce of MongoengineConnectionField for non db fields

eg;

class Person(Document)
    first_name = mongoengine.StringField(required=True)
    last_name = mongoengine.StringField(required=True)

class Person(MongoengineObjectType):
    class Meta:
        model = models.Person
        interfaces = (Node,)

    friends_suggestions = MongoengineConnectionField("Person")

    def resolve_fiends_suggestions(self,info,**kwargs):
        return Person.objects.no_dereference.all()

Author: arunsureshkumar

graphene_mongo/fields.py

@@ -7,6 +7,7 @@
 import mongoengine
 from bson import DBRef
 from graphene import Context
+from graphene.types.utils import get_type
 from graphene.utils.str_converters import to_snake_case
 from graphql import ResolveInfo
 from promise import Promise
@@ -186,6 +187,7 @@ def get_reference_field(r, kv):
 
     @property
     def fields(self):
+        self._type = get_type(self._type)
         return self._type._meta.fields
 
     def get_queryset(self, model, info, required_fields=list(), **args):
@@ -214,8 +216,9 @@ def default_resolver(self, _root, info, required_fields=list(), **args):
 
         if _root is not None:
             field_name = to_snake_case(info.field_name)
-            if getattr(_root, field_name, []) is not None:
-                args["pk__in"] = [r.id for r in getattr(_root, field_name, [])]
+            if field_name in _root._fields_ordered:
+                if getattr(_root, field_name, []) is not None:
+                    args["pk__in"] = [r.id for r in getattr(_root, field_name, [])]
 
         connection_args = {
             "first": args.pop("first", None),