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 close all open documents and try again
  {% end %}

This can be called using

self.render("logout.html", logout_error=True)

If the logout is successful, I have to do

self.render("logout.html", logout_error=False)

If I ignore logout_error=False, I get

NameError: global name 'logout_error' is not defined

If there are a lot of flags (which are false), the keyword arguments can pile up. Is there a way I can ask the template to consider logout_error as False if it does not exist?

Answer 1

Hacking around using locals().get() is one way to do it. Another, bit more orthodox is using try. Tornado template supports it, so you can:

{% try %}
  {% if logout_error %}
    Oops! The logout failed. Please close all open documents and try again
  {% end %}
{% except %}
{% end %}