Twig (template engine)

Twig is a template engine for the PHP programming language. Its syntax originates from Jinja and Django templates.^[3] It's an open source product^[4] licensed under a BSD License and maintained by Fabien Potencier. The initial version was created by Armin Ronacher. Symfony PHP framework comes with a bundled support for Twig as its default template engine since version 2.^[5]

The same template language is used by the Nunjucks template engine, thus Nunjucks is also supported by the following tools.

• Complex control flow
• Automatic escaping
• Template inheritance
• Variable filters^[6]
• i18n support (gettext)
• Macros
• Fully extendable^[3][7]

Twig is supported by the following integrated development environments:^[3]

• Eclipse via the Twig plugin
• Komodo and Komodo Edit via the Twig highlight/syntax check mode
• NetBeans via the Twig syntax plugin (until 7.1, native as of 7.2)
• PhpStorm (native as of 2.1)
• IntelliJ IDEs, including WebStorm, via a plugin

And the text editors:

• Atom via the PHP-twig for atom
• Emacs via web-mode.el
• Notepad++ via the Notepad++ Twig Highlighter
• Sublime Text via the Twig bundle
• TextMate via the Twig bundle
• Vim via the Jinja syntax plugin or the vim-twig plugin
• Brackets via Brackets Twig
• Visual Studio Code via the Twig extension
• GTKSourceView via the Twig language definition
• Coda via the Twig syntax mode
• Coda 2 via the other Twig syntax mode
• SubEthaEdit via the Twig syntax mode

Twig defines three kinds of delimiters:

• {{ ... }}, to print the content of variables or the result of evaluating an expression (e.g.: an inherited Twig template with {{ parent() }}).
• {# ... #}, to add comments in the templates. These comments aren't included in the rendered page.
• {% ... %}, to execute statements, such as for-loops.
  • {% set foo = 'bar' %}, to assign.^[8]
  • {% if i is defined and i == 1%} ... {% endif %}: condition.
  • {% for i in 0..10 %} ... {% endfor %}: counter in a loop.

The apostrophe (') is the escape character.

To create an iterative array:

{% set myArray = [1, 2] %}

An associative array:

{% set myArray = {'key': 'value'} %}

The operators precedence is,^[3] from the less to more priority:

The filters provide some treatments on an expression, when placed after it, separated by pipes. For example:^[6]

• capitalize: changes a string's first letter to capital.
• upper: changes a whole string to capital.
• first: displays the first line of an array.
• length: returns a variable size.

• loop contains the current loop information. For example loop.index corresponds to the number of iterations which have already occurred.
• The global variables begin with underscores. For example:
  • _route (URL part located after the domain)
  • _self (current file name)

  So, to the a page route: {{ path(app.request.attributes.get('_route'), app.request.attributes.get('_route_params')) }}

• The CGI environment variables, such as {{ app.request.server.get('SERVER_NAME') }}.

The example below demonstrates some basic features of Twig.

{% extends "base.html" %}
{% block navigation %}
    <ul id="navigation">
    {% for item in navigation %}
        <li>
            <a href="{{ item.href }}">
                {% if item.level == 2 %}&nbsp;&nbsp;{% endif %}
                {{ item.caption|upper }}
            </a>
        </li>
    {% endfor %}
    </ul>
{% endblock navigation %}

• Smarty

• Twig official website
• Fabien Potencier (2009-10-07). "Templating Engines in PHP". Retrieved 2023-10-27.