Tests

A test is a function that runs against some value or variable and returns true and false.

Example of a test called divisibleby:

{% if myNumber is divisibleby 3 %}
{% if myNumber is divisibleby(3) %}

As shown in the example, the keyword is is used to evaluate a test (or any other boolean expression).

Syntax Examples

The following example shows a variety of boolean conditions, including some tests, which may help to understand Jinja syntax related to boolean expressions.

{% if category == 'news' %}
  <p>Displaying news articles...</p>
{% elif items is sequence and items|length > 5 %}
  <p>Displaying a long list of items...</p>
{% elif user.is_logged_in %}
  <p>Welcome back, user!</p>
{% else %}
  <p>Please log in.</p>
{% endif %}

Jinja also includes explicit syntax for negating boolean conditions.

{% if not items is empty %}
  <p>The list of items is not empty.</p>
{% endif %}

{% if value is not none %}
  <p>The value is not None.</p>
{% endif %}

Available Tests

The official distribution of Jinja includes a number of built-in tests.

Static Shock uses a Pub package for Jinja support, which may or may not support all standard tests.

Static Shock currently doesn't add any custom tests, but may in the future.