python runtime_error ai_generated true

jinja2.exceptions.UndefinedError: 'user' is undefined

ID: python/flask-jinja2-undefinederror-variable-undefined

Also available as: JSON · Markdown · 中文
80%Fix Rate
84%Confidence
0Evidence
2024-04-12First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

Template references a variable that was not passed to the template context.

generic

中文

模板引用了一个未传递给模板上下文的变量。

Workarounds

  1. 95% success Pass variable in render_template 
    return render_template('index.html', user=current_user)
  2. 90% success Use default filter in template 
    {{ user | default('Guest') }}

Dead Ends

Common approaches that don't work:

  1. Adding variable in wrong route 50% fail

    Variable must be passed in the specific route that renders the template.

  2. Using global variable without context 70% fail

    Flask templates don't inherit global variables without explicit passing.