Handling an undefined template variable in Tornado

Question

This is a tornado template (say, in the file logout.html) I render on an error in the logout process:

  {% if logout_error %}
    Oops! The logout failed. Please         


        

Answer 1

The "Tornado way" is to not have undeclared variables. It's more zen to declare the variables explicit.

Workaround:

{% if 'grok' in globals() %}
  {{grok}}
{% end %}

{% if globals().get('grok_error', False) %}
  error message
{% end %}