use
#
Примечание
Horizontal reuse is an advanced Twig feature that is hardly ever needed in regular templates. It is mainly used by projects that need to make template blocks reusable without using inheritance.
Template inheritance is one of the most powerful features of Twig but it is limited to single inheritance; a template can only extend one other template. This limitation makes template inheritance simple to understand and easy to debug:
{% extends "base.html" %}
{% block title %}{% endblock %}
{% block content %}{% endblock %}
Horizontal reuse is a way to achieve the same goal as multiple inheritance, but without the associated complexity:
{% extends "base.html" %}
{% use "blocks.html" %}
{% block title %}{% endblock %}
{% block content %}{% endblock %}
The use
statement tells Twig to import the blocks defined in
blocks.html
into the current template (it’s like macros, but for blocks):
{# blocks.html #}
{% block sidebar %}{% endblock %}
In this example, the use
statement imports the sidebar
block into the
main template. The code is mostly equivalent to the following one (the
imported blocks are not outputted automatically):
{% extends "base.html" %}
{% block sidebar %}{% endblock %}
{% block title %}{% endblock %}
{% block content %}{% endblock %}
Примечание
The use
tag only imports a template if it does not extend another
template, if it does not define macros, and if the body is empty. But it
can use other templates.
Примечание
Because use
statements are resolved independently of the context
passed to the template, the template reference cannot be an expression.
The main template can also override any imported block. If the template
already defines the sidebar
block, then the one defined in blocks.html
is ignored. To avoid name conflicts, you can rename imported blocks:
{% extends "base.html" %}
{% use "blocks.html" with sidebar as base_sidebar, title as base_title %}
{% block sidebar %}{% endblock %}
{% block title %}{% endblock %}
{% block content %}{% endblock %}
The parent()
function automatically determines the correct inheritance
tree, so it can be used when overriding a block defined in an imported
template:
{% extends "base.html" %}
{% use "blocks.html" %}
{% block sidebar %}
{{ parent() }}
{% endblock %}
{% block title %}{% endblock %}
{% block content %}{% endblock %}
In this example, parent()
will correctly call the sidebar
block from
the blocks.html
template.
Совет
Renaming allows you to simulate inheritance by calling the «parent» block:
{% extends "base.html" %}
{% use "blocks.html" with sidebar as parent_sidebar %}
{% block sidebar %}
{{ block('parent_sidebar') }}
{% endblock %}
Примечание
You can use as many use
statements as you want in any given template.
If two imported templates define the same block, the latest one wins.