Merge pull request #148 from khankuan/patch-2

Fix graphiql refreshing operationName undefined

Author: syrusakbary

Diff for: graphene_django/views.py

@@ -287,6 +287,8 @@ def get_graphql_params(request, data):
                 raise HttpError(HttpResponseBadRequest('Variables are invalid JSON.'))
 
         operation_name = request.GET.get('operationName') or data.get('operationName')
+        if operation_name == "null":
+            operation_name = None
 
         return query, variables, operation_name, id