Warning Twig version 1.x is no longer maintained.
defined
defined
checks if a variable is defined in the current context. This is very
useful if you use the strict_variables
option:
1 2 3 4 5 6 7 8 9 10 11 12 13
{# defined works with variable names #}
{% if foo is defined %}
...
{% endif %}
{# and attributes on variables names #}
{% if foo.bar is defined %}
...
{% endif %}
{% if foo['bar'] is defined %}
...
{% endif %}
When using the defined
test on an expression that uses variables in some
method calls, be sure that they are all defined first:
1 2 3
{% if var is defined and foo.method(var) is defined %}
...
{% endif %}