1``constant`` 2============ 3 4.. versionadded: 1.12.1 5 constant now accepts object instances as the second argument. 6 7.. versionadded: 1.28 8 Using ``constant`` with the ``defined`` test was added in Twig 1.28. 9 10``constant`` returns the constant value for a given string: 11 12.. code-block:: jinja 13 14 {{ some_date|date(constant('DATE_W3C')) }} 15 {{ constant('Namespace\\Classname::CONSTANT_NAME') }} 16 17As of 1.12.1 you can read constants from object instances as well: 18 19.. code-block:: jinja 20 21 {{ constant('RSS', date) }} 22 23Use the ``defined`` test to check if a constant is defined: 24 25.. code-block:: jinja 26 27 {% if constant('SOME_CONST') is defined %} 28 ... 29 {% endif %} 30