``macro``
=========
Macros are comparable with functions in regular programming languages. They
are useful to put often used HTML idioms into reusable elements to not repeat
yourself.
Here is a small example of a macro that renders a form element:
.. code-block:: jinja
{% macro input(name, value, type, size) %}
<input type="{{ type|default('text') }}" name="{{ name }}" value="{{ value|e }}" size="{{ size|default(20) }}" />
{% endmacro %}
Macros differs from native PHP functions in a few ways:
* Default argument values are defined by using the ``default`` filter in the
macro body;
* Arguments of a macro are always optional.
But as with PHP functions, macros don't have access to the current template
variables.
.. tip::
You can pass the whole context as an argument by using the special
``_context`` variable.
Macros can be defined in any template, and need to be "imported" before being
used (see the documentation for the :doc:`import<../tags/import>` tag for more
information):
.. code-block:: jinja
{% import "forms.html" as forms %}
The above ``import`` call imports the "forms.html" file (which can contain only
macros, or a template and some macros), and import the functions as items of
the ``forms`` variable.
The macro can then be called at will:
.. code-block:: jinja
<p>{{ forms.input('username') }}</p>
<p>{{ forms.input('password', null, 'password') }}</p>
If macros are defined and used in the same template, you can use the
special ``_self`` variable to import them:
.. code-block:: jinja
{% import _self as forms %}
<p>{{ forms.input('username') }}</p>
.. warning::
When you define a macro in the template where you are going to use it, you
might be tempted to call the macro directly via ``_self.input()`` instead
of importing it; even if seems to work, this is just a side-effect of the
current implementation and it won't work anymore in Twig 2.x.
When you want to use a macro in another macro from the same file, you need to
import it locally:
.. code-block:: jinja
{% macro input(name, value, type, size) %}
<input type="{{ type|default('text') }}" name="{{ name }}" value="{{ value|e }}" size="{{ size|default(20) }}" />
{% endmacro %}
{% macro wrapped_input(name, value, type, size) %}
{% import _self as forms %}
<div class="field">
{{ forms.input(name, value, type, size) }}
</div>
{% endmacro %}
.. seealso:: :doc:`from<../tags/from>`, :doc:`import<../tags/import>`
|
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