macro
ΒΆ
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:
{% 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.
- If extra positional arguments are passed to a macro, they end up in the
special
varargs
variable as a list of values.
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 import tag for more information):
{% 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:
<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:
{% 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:
{% 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 %}