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Symfony2 – Franz Jordán 2011
Twig Template Caching
Twig is fast. Each Twig template is compiled down to a native PHP class that is rendered at
runtime. The compiled classes are located in the app/cache/{environment}/twig directory
(where{environment} is the environment, such as dev or prod) and in some cases can be
useful while debugging. See Environments for more information on environments.
When debug mode is enabled (common in the dev environment), a Twig template will be
automatically recompiled when changes are made to it. This means that during development you
can happily make changes to a Twig template and instantly see the changes without needing to
worry about clearing any cache.
When debug mode is disabled (common in the prod environment), however, you must clear the
Twig cache directory so that the Twig templates will regenerate. Remember to do this when
deploying your application.
Template Inheritance and Layouts
More often than not, templates in a project share common elements, like the header, footer,
sidebar or more. In Symfony2, we like to think about this problem differently: a template can be
decorated by another one. This works exactly the same as PHP classes: template inheritance
allows you to build a base "layout" template that contains all the common elements of your site
defined as blocks (think "PHP class with base methods"). A child template can extend the base
layout and override any of its blocks (think "PHP subclass that overrides certain methods of its
parent class").
First, build a base layout file:
{# app/Resources/views/base.html.twig #}
{% block title %}Test Application{% endblock %}
{% block sidebar %}
Home
Blog
{% endblock %}
{% block body %}{% endblock %}
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