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]

Twig

Original author(s)	Armin Ronacher,[1] Fabien Potencier
Developer(s)	SensioLabs
Initial release	October 12, 2009 (2009-10-12)
Stable release	3.0.3[2] / February 11, 2020 (2020-02-11)
Repository	github.com/twigphp/Twig
Written in	PHP
Operating system	Cross-platform
Type	Template engine
License	BSD License
Website	twig.symfony.com

Features

• 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)

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

Syntax

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'} %}

Operators precedence

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

Operator	Role
b-and	Boolean and
b-xor	Exclusive or
b-or	Boolean or
or	Or
and	And
==	Is equal?
!=	Is different?
<	Inferior
>	Superior
>=	Superior or equal
<=	Inferior or equal
in	Into
matches	Corresponds
starts with	Begins by
ends with	Finishes by
..	Sequence (ex: 1..5)
+	Plus
-	Less
~	Concatenation
*	Multiplication
/	Division
//	Division rounded to lower
%	Modulo
is	Test (ex: is defined or is not empty)
**	Power
|	Filter[6]
[]	Array entry
.	Attribute or method from an object (ex: country.name)

Filters

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

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

Special variables

• loop contains the current loop information. For example loop.index corresponds to the number of iterations which have already occurred.
• The global variables begin by 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') }}.

Example

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 %}

See also

• Smarty

References

1. "mitsuhiko/twig". August 13, 2019 – via GitHub.
2. "Releases · twigphp/Twig". GitHub.
3. "Twig for Template Designers - Documentation - Twig - The flexible, fast, and secure PHP template engine". twig.symfony.com.
4. "twigphp/Twig". July 1, 2020 – via GitHub.
5. "Symfony2 Documentation — Documentation". web.archive.org. August 5, 2010.
6. "Filters - Documentation - Twig - The flexible, fast, and secure PHP template engine". twig.symfony.com.
7. "Extending Twig - Documentation - Twig - The flexible, fast, and secure PHP template engine". twig.symfony.com.
8. "set - Documentation - Twig - The flexible, fast, and secure PHP template engine". twig.symfony.com.

External links

• Twig official website
• Templating Engines in PHP, Fabien Potencier, 2009