Twig (template engine)

Twig

Original author(s)	Armin Ronacher, Fabien Potencier
Developer(s)	SensioLabs
Initial release	October 12, 2009 (2009-10-12)
Stable release	1.24.0 / January 26, 2016 (2016-01-26)
Development status	Active
Written in	PHP
Operating system	Cross-platform
Type	Template engine
License	BSD License
Website	twig.symfony.com

Twig is a template engine for the PHP programming language. Its syntax originates from Jinja and Django templates. It's an open source product licensed under a BSD License and maintained by Fabien Potencier. The initial version was created by Armin Ronacher. Symfony2 PHP framework comes with a bundled support for Twig as its default template engine.

Features

• complex control flow
• automatic escaping
• template inheritance
• variable filters
• i18n support (gettext)
• macros
• fully extendable

Twig is supported by the following integrated development environments:

• Eclipse
• Komodo
• NetBeans
• PhpStorm (natively)
• Visual Studio

And the text editors:

• Atom
• emacs
• Notepad++
• Sublime Text
• TextMate
• vim

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.
  • {% 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.

Operators precedence

The operators precedence is, 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
[]	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:

• capitalize: changes a string first letter in capital.
• upper: changes a while 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
• Twital, a template engine that compile its sources into Twig templates, adding some features as context-aware escaping, attribute-expression and creating more readable templates.

External links

• Twig official website
• Potencier, Fabien (October 7, 2009). "Templating Engines in PHP". Retrieved 6 April 2011. 
• Potencier, Fabien (November 20, 2009). "Templating Engines in PHP (Перевод: Шаблонизаторы в PHP)" (in Russian). Retrieved 6 April 2011.