check d object must be dict to get url or id

app.py

@@ -285,9 +285,12 @@ def domain(url):
 
 @app.template_filter()
 def url_or_id(d):
+    if isinstance(d, dict):
         if ("url" in d) and isinstance(d["url"], str):
             return d["url"]
+        else:
             return d["id"]
+    return ""
 
 
 @app.template_filter()