--- /dev/null
+``defined``
+===========
+
+``defined`` checks if a variable is defined in the current context. This is very
+useful if you use the ``strict_variables`` option:
+
+.. code-block:: jinja
+
+ {# 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:
+
+.. code-block:: jinja
+
+ {% if var is defined and foo.method(var) is defined %}
+ ...
+ {% endif %}