This document describes the syntax and semantics of the template engine and will be most useful as reference to those creating Twig templates.
A template is simply a text file. It can generate any text-based format (HTML,
XML, CSV, LaTeX, etc.). It doesn't have a specific extension, .html or
.xml are just fine.
A template contains variables or expressions, which get replaced with values when the template is evaluated, and tags, which control the logic of the template.
Below is a minimal template that illustrates a few basics. We will cover the details later in that document:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<title>My Webpage</title>
</head>
<body>
<ul id="navigation">
{% for item in navigation %}
<li><a href="{{ item.href }}">{{ item.caption }}</a></li>
{% endfor %}
</ul>
<h1>My Webpage</h1>
{{ a_variable }}
</body>
</html>
There are two kinds of delimiters: {% ... %} and {{ ... }}. The first one
is used to execute statements such as for-loops, the latter prints the result
of an expression to the template.
Modern IDEs support syntax highlighting and auto-completion for a large range of languages. As Twig syntax is quite similar to Jinja and Django templates, IDEs that support these two Python templating systems should also support Twig.
If you use Textmate, you can use the Jinja bundle or the Django one.
If you use Vim, you can use the Jinja syntax plugin.
The application passes variables to the templates you can mess around in the template. Variables may have attributes or elements on them you can access too. How a variable looks like, heavily depends on the application providing those.
You can use a dot (.) to access attributes of a variable, alternative the
so-called "subscript" syntax ([]) can be used. The following lines do the
same:
{{ foo.bar }}
{{ foo['bar'] }}
It's important to know that the curly braces are not part of the variable but the print statement. If you access variables inside tags don't put the braces around.
If a variable or attribute does not exist you will get back a null value
(which can be tested with the none expression).
Implementation
For convenience sake
foo.bardoes the following things on the PHP layer:
- check if
foois an array andbara valid element;- if not, and if
foois an object, check thatbaris a valid property;- if not, and if
foois an object, check thatbaris a valid method (even ifbaris the constructor - use__construct()instead);- if not, and if
foois an object, check thatgetBaris a valid method;- if not, return a
nullvalue.
foo['bar']on the other hand works mostly the same with the a small difference in the order:
- check if
foois an array andbara valid element;- if not, return a
nullvalue.Using the alternative syntax is also useful to dynamically get attributes from arrays:
foo[bar]
Twig always references two special variables (mostly useful for macros):
_self: references the current template (was self before 0.9.9);_context: references the current context.Variables can by modified by filters. Filters are separated from the
variable by a pipe symbol (|) and may have optional arguments in
parentheses. Multiple filters can be chained. The output of one filter is
applied to the next.
{{ name|striptags|title }} for example will remove all HTML tags from the
name and title-cases it. Filters that accept arguments have parentheses
around the arguments, like a function call. This example will join a list by
commas: {{ list|join(', ') }}.
The built-in filters section below describes all the built-in filters.
Beside filters, there are also so called "tests" available. Tests can be used
to test a variable against a common expression. To test a variable or
expression you add is plus the name of the test after the variable. For
example to find out if a variable is odd, you can do name is odd which will
then return true or false depending on if name is odd or not.
Tests can accept arguments too:
{% if loop.index is divisibleby(3) %}
Tests can be negated by prepending them with not:
{% if loop.index is not divisibleby(3) %}
The built-in tests section below describes all the built-in tests.
To comment-out part of a line in a template, use the comment syntax {# ... #}.
This is useful to comment out parts of the template for debugging or to
add information for other template designers or yourself:
{# note: disabled template because we no longer use this
{% for user in users %}
...
{% endfor %}
#}
In the default configuration whitespace is not further modified by the
template engine, so each whitespace (spaces, tabs, newlines etc.) is returned
unchanged. If the application configures Twig to trim_blocks the first
newline after a template tag is removed automatically (like in PHP).
It is sometimes desirable or even necessary to have Twig ignore parts it would
otherwise handle as variables or blocks. For example if the default syntax is
used and you want to use {{ as raw string in the template and not start a
variable you have to use a trick.
The easiest way is to output the variable delimiter ({{) by using a variable
expression:
{{ '{{' }}
For bigger sections it makes sense to mark a block raw. For example to put
Twig syntax as example into a template you can use this snippet:
{% raw %}
<ul>
{% for item in seq %}
<li>{{ item }}</li>
{% endfor %}
</ul>
{% endraw %}
The most powerful part of Twig is template inheritance. Template inheritance allows you to build a base "skeleton" template that contains all the common elements of your site and defines blocks that child templates can override.
Sounds complicated but is very basic. It's easiest to understand it by starting with an example.
This template, which we'll call base.html, defines a simple HTML skeleton
document that you might use for a simple two-column page. It's the job of
"child" templates to fill the empty blocks with content:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
{% block head %}
<link rel="stylesheet" href="style.css" />
<title>{% block title %}{% endblock %} - My Webpage</title>
{% endblock %}
</head>
<body>
<div id="content">{% block content %}{% endblock %}</div>
<div id="footer">
{% block footer %}
© Copyright 2009 by <a href="http://domain.invalid/">you</a>.
{% endblock %}
</div>
</body>
</html>
In this example, the {% block %} tags define four blocks that child
templates can fill in. All the block tag does is to tell the template engine
that a child template may override those portions of the template.
A child template might look like this:
{% extends "base.html" %}
{% block title %}Index{% endblock %}
{% block head %}
{% parent %}
<style type="text/css">
.important { color: #336699; }
</style>
{% endblock %}
{% block content %}
<h1>Index</h1>
<p class="important">
Welcome on my awesome homepage.
</p>
{% endblock %}
The {% extends %} tag is the key here. It tells the template engine that
this template "extends" another template. When the template system evaluates
this template, first it locates the parent. The extends tag should be the
first tag in the template.
The filename of the template depends on the template loader. For example the
Twig_Loader_Filesystem allows you to access other templates by giving the
filename. You can access templates in subdirectories with a slash:
{% extends "layout/default.html" %}
But this behavior can depend on the application embedding Twig. Note that
since the child template doesn't define the footer block, the value from the
parent template is used instead.
You can't define multiple {% block %} tags with the same name in the same
template. This limitation exists because a block tag works in "both"
directions. That is, a block tag doesn't just provide a hole to fill - it also
defines the content that fills the hole in the parent. If there were two
similarly-named {% block %} tags in a template, that template's parent
wouldn't know which one of the blocks' content to use.
If you want to print a block multiple times you can however use the display
tag:
<title>{% block title %}{% endblock %}</title>
<h1>{% display title %}</h1>
{% block body %}{% endblock %}
Like PHP, Twig does not support multiple inheritance. So you can only have one extends tag called per rendering.
It's possible to render the contents of the parent block by using the parent
tag. This gives back the results of the parent block:
{% block sidebar %}
<h3>Table Of Contents</h3>
...
{% parent %}
{% endblock %}
Twig allows you to put the name of the block after the end tag for better readability:
{% block sidebar %}
{% block inner_sidebar %}
...
{% endblock inner_sidebar %}
{% endblock sidebar %}
However the name after the endblock word must match the block name.
Blocks can be nested for more complex layouts. Per default, blocks have access to variables from outer scopes:
{% for item in seq %}
<li>{% block loop_item %}{{ item }}{% endblock %}</li>
{% endfor %}
For blocks with few content, it's possible to have a shortcut syntax. The following constructs do the same:
{% block title %}
{{ page_title|title }}
{% endblock %}
{% block title page_title|title %}
Twig supports dynamic inheritance by using a variable as the base template:
{% extends some_var %}
If the variable evaluates to a Twig_Template object, Twig will use it as the
parent template:
// {% extends layout %}
$layout = $twig->loadTemplate('some_layout_template.twig');
$twig->display('template.twig', array('layout' => $layout));
As a matter of fact, the template name can be any valid expression. So, it's also possible to make the inheritance mechanism conditional:
{% extends standalone ? "minimum.html" : "base.html" %}
In this example, the template will extend the "minimum.html" layout template
if the standalone variable evaluates to true, and "base.html" otherwise.
Per default included templates are passed the current context.
The context that is passed to the included template includes variables defined in the template:
{% for box in boxes %}
{% include "render_box.html" %}
{% endfor %}
The included template render_box.html is able to access box.
When generating HTML from templates, there's always a risk that a variable will include characters that affect the resulting HTML. There are two approaches: manually escaping each variable or automatically escaping everything by default.
Twig supports both, but what is used depends on the application configuration. The default configuration is no automatic escaping for various reasons:
Escaping everything except of safe values will also mean that Twig is escaping variables known to not include HTML such as numbers which is a huge performance hit.
The information about the safety of a variable is very fragile. It could happen that by coercing safe and unsafe values the return value is double escaped HTML.
Escaping is only supported if the escaper extension has been enabled.
If manual escaping is enabled it's your responsibility to escape variables
if needed. What to escape? If you have a variable that may include any of
the following chars (>, <, &, or ") you have to escape it unless
the variable contains well-formed and trusted HTML. Escaping works by piping
the variable through the |e filter: {{ user.username|e }}.
Automatic escaping is enabled when the escaper extension has been enabled.
Whether automatic escaping is enabled or not, you can mark a section of a
template to be escaped or not by using the autoescape tag:
{% autoescape on %}
Everything will be automatically escaped in this block
{% endautoescape %}
{% autoescape off %}
Everything will be outputed as is in this block
{% endautoescape %}
{% autoescape on js %}
Everything will be automatically escaped in this block
using the js escaping strategy
{% endautoescape %}
When automatic escaping is enabled everything is escaped by default except for
values explicitly marked as safe. Those can be marked in the template by using
the |safe filter.
Functions returning template data (like macros and parent) always return
safe markup.
Twig is smart enough to not escape an already escaped value by the
escapefilter.
The chapter for developers give more information about when and how automatic escaping is applied.
A control structure refers to all those things that control the flow of a
program - conditionals (i.e. if/elseif/else), for-loops, as well as
things like blocks. Control structures appear inside {% ... %} blocks.
Loop over each item in a sequence. For example, to display a list of users
provided in a variable called users:
<h1>Members</h1>
<ul>
{% for user in users %}
<li>{{ user.username|e }}</li>
{% endfor %}
</ul>
A sequence can be either an array or an object implementing the
Iteratorinterface.
If you do need to iterate over a sequence of numbers, you can use the ..
operator (as of Twig 0.9.5):
{% for i in 0..10 %}
* {{ i }}
{% endfor %}
The above snippet of code would print all numbers from 0 to 10.
It can be also useful with letters:
{% for letter in 'a'..'z' %}
* {{ letter }}
{% endfor %}
The .. operator can take any expression at both sides:
{% for letter in 'a'|upper..'z'|upper %}
* {{ letter }}
{% endfor %}
If you need a step different from 1, you can use the range filter instead:
{% for i in 0|range(10, 2) %}
* {{ i }}
{% endfor %}
Inside of a for loop block you can access some special variables (if you
don't need them, you can add without loop at the end of the for statement
for a small speed boost):
| Variable | Description |
|---|---|
loop.index |
The current iteration of the loop. (1 indexed) |
loop.index0 |
The current iteration of the loop. (0 indexed) |
loop.revindex |
The number of iterations from the end of the loop (1 indexed) |
loop.revindex0 |
The number of iterations from the end of the loop (0 indexed) |
loop.first |
True if first iteration |
loop.last |
True if last iteration |
loop.length |
The number of items in the sequence |
loop.parent |
The parent context |
The
loop.length,loop.revindex,loop.revindex0, andloop.lastvariables are only available for PHP arrays, or objects that implement theCountableinterface (as of Twig 0.9.7).
Unlike in PHP it's not possible to
breakorcontinuein a loop.
If no iteration took place because the sequence was empty, you can render a
replacement block by using else:
<ul>
{% for user in users %}
<li>{{ user.username|e }}</li>
{% else %}
<li><em>no user found</em></li>
{% endfor %}
</ul>
By default, a loop iterates over the values of the sequence. You can iterate
on keys by using the keys filter:
<h1>Members</h1>
<ul>
{% for key in users|keys %}
<li>{{ key }}</li>
{% endfor %}
</ul>
You can also access both keys and values:
<h1>Members</h1>
<ul>
{% for key, user in users %}
<li>{{ key }}: {{ user.username|e }}</li>
{% endfor %}
</ul>
On Twig before 0.9.3, you need to use the
itemsfilter to access both the keys and values ({% for key, value in users|items %}).
The if statement in Twig is comparable with the if statements of PHP. In the
simplest form you can use it to test if a variable is defined, not empty or
not false:
{% if users %}
<ul>
{% for user in users %}
<li>{{ user.username|e }}</li>
{% endfor %}
</ul>
{% endif %}
For multiple branches elseif and else can be used like in PHP. You can use
more complex expressions there too:
{% if kenny.sick %}
Kenny is sick.
{% elseif kenny.dead %}
You killed Kenny! You bastard!!!
{% else %}
Kenny looks okay --- so far
{% endif %}
Macros are comparable with functions in regular programming languages. They are useful to put often used HTML idioms into reusable elements to not repeat yourself.
Here is a small example of a macro that renders a form element:
{% macro input(name, value, type, size) %}
<input type="{{ type|default('text') }}" name="{{ name }}" value="{{ value|e }}" size="{{ size|default(20) }}" />
{% endmacro %}
Macros differs from native PHP functions in a few ways:
Default argument values are defined by using the default filter in the
macro body;
Arguments of a macro are always optional.
But as PHP functions, macros don't have access to the current template variables.
You can pass the whole context as an argument by using the special
_contextvariable.
Macros can be defined in any template, and need to be "imported" before being used (see the Import section for more information):
{% import "forms.html" as forms %}
The above import call imports the "forms.html" file (which can contain only
macros, or a template and some macros), and import the functions as items of
the forms variable.
The macro can then be called at will:
<p>{{ forms.input('username') }}</p>
<p>{{ forms.input('password', none, 'password') }}</p>
If macros are defined and used in the same template, you can use the
special _self variable, without importing them:
<p>{{ _self.input('username') }}</p>
When you want to use a macro in another one from the same file, use the _self
variable:
{% macro input(name, value, type, size) %}
<input type="{{ type|default('text') }}" name="{{ name }}" value="{{ value|e }}" size="{{ size|default(20) }}" />
{% endmacro %}
{% macro wrapped_input(name, value, type, size) %}
<div class="field">
{{ _self.input(name, value, type, size) }}
</div>
{% endmacro %}
When the macro is defined in another file, you need to import it:
{# forms.html #}
{% macro input(name, value, type, size) %}
<input type="{{ type|default('text') }}" name="{{ name }}" value="{{ value|e }}" size="{{ size|default(20) }}" />
{% endmacro %}
{# shortcuts.html #}
{% macro wrapped_input(name, value, type, size) %}
{% import "forms.html" as forms %}
<div class="field">
{{ forms.input(name, value, type, size) }}
</div>
{% endmacro %}
Filter sections allow you to apply regular Twig filters on a block of template
data. Just wrap the code in the special filter section:
{% filter upper %}
This text becomes uppercase
{% endfilter %}
You can also chain filters:
{% filter lower|escape %}
<strong>SOME TEXT</strong>
{% endfilter %}
It should returns <strong>some text</strong>.
Inside code blocks you can also assign values to variables. Assignments use
the set tag and can have multiple targets:
{% set foo = 'foo' %}
{% set foo = [1, 2] %}
{% set foo = ['foo': 'bar'] %}
{% set foo = 'foo' ~ 'bar' %}
{% set foo, bar = 'foo', 'bar' %}
The set tag can also be used to 'capture' chunks of HTML (new in Twig
0.9.6):
{% set foo %}
<div id="pagination">
...
</div>
{% endset %}
The extends tag can be used to extend a template from another one. You can
have multiple of them in a file but only one of them may be executed at the
time. There is no support for multiple inheritance. See the section about
Template inheritance above for more information.
Blocks are used for inheritance and act as placeholders and replacements at the same time. They are documented in detail as part of the section about Template inheritance above.
The include statement is useful to include a template and return the
rendered contents of that file into the current namespace:
{% include 'header.html' %}
Body
{% include 'footer.html' %}
Included templates have access to the variables of the active context.
You can also restrict the variables passed to the template by explicitly pass them as an array:
{% include 'foo' with ['foo': 'bar'] %}
{% set vars as ['foo': 'bar'] %}
{% include 'foo' with vars %}
The
withkeyword is supported as of Twig 0.9.5.
When including a template created by an end user, you should consider sandboxing it. More information in the "Twig for Developers" chapter.
The template name can be any valid Twig expression:
{% include some_var %}
{% include ajax ? 'ajax.html' : 'not_ajax.html' %}
And if the variable evaluates to a Twig_Template object, Twig will use it
directly:
// {% include template %}
$template = $twig->loadTemplate('some_template.twig');
$twig->display('template.twig', array('template' => $template));
Twig supports putting often used code into macros. These macros can go into different templates and get imported from there.
Imagine we have a helper module that renders forms (called forms.html):
{% macro input(name, value, type, size) %}
<input type="{{ type|default('text') }}" name="{{ name }}" value="{{ value|e }}" size="{{ size|default(20) }}" />
{% endmacro %}
{% macro textarea(name, value, rows) %}
<textarea name="{{ name }}" rows="{{ rows|default(10) }}" cols="{{ cols|default(40) }}">{{ value|e }}</textarea>
{% endmacro %}
Importing these macros in a template is as easy as using the import tag:
{% import 'forms.html' as forms %}
<dl>
<dt>Username</dt>
<dd>{{ forms.input('username') }}</dd>
<dt>Password</dt>
<dd>{{ forms.input('password', none, 'password') }}</dd>
</dl>
<p>{{ forms.textarea('comment') }}</p>
Importing is not needed if the macros and the template are defined in the file;
use the special _self variable instead:
{# index.html template #}
{% macro textarea(name, value, rows) %}
<textarea name="{{ name }}" rows="{{ rows|default(10) }}" cols="{{ cols|default(40) }}">{{ value|e }}</textarea>
{% endmacro %}
<p>{{ _self.textarea('comment') }}</p>
But you can still create an alias by importing from the _self variable:
{# index.html template #}
{% macro textarea(name, value, rows) %}
<textarea name="{{ name }}" rows="{{ rows|default(10) }}" cols="{{ cols|default(40) }}">{{ value|e }}</textarea>
{% endmacro %}
{% import _self as forms %}
<p>{{ forms.textarea('comment') }}</p>
When the i18n extension is enabled, use the trans block to mark parts in
the template as translatable:
{% trans "Hello World!" %}
{% trans string_var %}
{% trans %}
Hello World!
{% endtrans %}
The
I18nextension only works if the PHP gettext extension is enabled.
In a translatable string, you can embed variables:
{% trans %}
Hello {{ name }}!
{% endtrans %}
{% trans "Hello {{ name }}!" %}is not a valid statement.
If you need to apply filters to the variables, you first need to assign the result to a variable:
{% set name as name|capitalize %}
{% trans %}
Hello {{ name }}!
{% endtrans %}
To pluralize a translatable string, use the plural block:
{% trans %}
Hey {{ name }}, I have one apple.
{% plural apple_count %}
Hey {{ name }}, I have {{ count }} apples.
{% endtrans %}
The plural tag should provide the count used to select the right string.
Within the translatable string, the special count variable always contain
the count value (here the value of apple_count).
Within an expression or in a tag, you can use the trans filter to translate
simple strings or variables (new in Twig 0.9.9):
{{ var|default(default_value|trans) }}
Twig allows basic expressions everywhere. These work very similar to regular PHP and even if you're not working with PHP you should feel comfortable with it.
The operator precedence is as follows, with the lowest-precedence operators
listed first: or, and, ==, !=, <, >, >=, <=, in, +, -,
~, *, /, %, //, not, and [.
When compiling deep-nested arrays or math expressions with Xdebug enabled, Twig can easily reach the default maximum nesting level set by Xdebug via the
xdebug.max_nesting_levelsetting; changing the default (100) to a bigger value solves the issue.
The simplest form of expressions are literals. Literals are representations for PHP types such as strings, numbers, and arrays. The following literals exist:
"Hello World": Everything between two double or single quotes is a
string. They are useful whenever you need a string in the template (for
example as arguments to function calls, filters or just to extend or
include a template).
42 / 42.23: Integers and floating point numbers are created by just
writing the number down. If a dot is present the number is a float,
otherwise an integer.
[foo, bar] (new in Twig 0.9.5): Arrays are defined by a sequence of
expressions separated by a comma (,) and wrapped with squared brackets
([]). As an array element can be any valid expression, arrays can be
nested. Like PHP, arrays can also have named items (hashes) like ['foo':
'foo', 'bar': 'bar']. You can even mix and match both syntaxes: ['foo':
'foo', 'bar'].
true / false: true represents the true value, false
represents the false value.
none: none represents no specific value (the equivalent of null in
PHP). This is the value returned when a variable does not exist.
Twig allows you to calculate with values. This is rarely useful in templates but exists for completeness' sake. The following operators are supported:
+: Adds two objects together (the operands are casted to numbers).
{{ 1 + 1 }} is 2.
-: Substracts the second number from the first one. {{ 3 - 2 }} is 1.
/: Divides two numbers. The return value will be a floating point number.
{{ 1 / 2 }} is {{ 0.5 }}.
%: Calculates the remainder of an integer division. {{ 11 % 7 }} is 4.
//: Divides two numbers and returns the truncated integer result. {{ 20 //
7 }} is 2.
*: Multiplies the left operand with the right one. {{ 2 * 2 }} would
return 4.
**: Raises the left operand to the power of the right operand. {{ 2**3
}} would return 8.
For if statements, for filtering or if expressions it can be useful to
combine multiple expressions:
and: Returns true if the left and the right operands are both true.
or: Returns true if the left or the right operand is true.
not: Negates a statement.
(expr): Groups an expression.
The following comparison operators are supported in any expression: ==,
!=, <, >, >=, and <=.
Besides PHP classic comparison operators, Twig also supports a shortcut notation when you want to test a value in a range:
{% if 1 < foo < 4 %}foo is between 1 and 4{% endif %}
The following operators are very useful but don't fit into any of the other two categories:
in (new in Twig 0.9.5): Performs containment test. Returns true if the
left operand is contained in the right. {{ 1 in [1, 2, 3] }} would for
example return true. To perform a negative test, the whole expression
should be prefixed with not ({{ not 1 in [1, 2, 3] }} would return
false).
.. (new in Twig 0.9.5): Creates a sequence based on the operand before
and after the operator (see the for tag for some usage examples).
|: Applies a filter.
~: Converts all operands into strings and concatenates them. {{ "Hello "
~ name ~ "!" }} would return (assuming name is 'John') Hello John!.
., []: Gets an attribute of an object.
?:: Twig supports the PHP ternary operator:
{{ foo ? 'yes' : 'no' }}dateThe date filter is able to format a date to a given format:
{{ post.published_at|date("m/d/Y") }}
The date filter accepts any date format supported by
DateTime and
DateTime instances.
formatThe format filter formats a given string by replacing the placeholders:
{# string is a format string like: I like %s and %s. #}
{{ string|format(foo, "bar") }}
{# returns I like foo and bar. (if the foo parameter equals to the foo string) #}
cycleThe cycle filter can be used to cycle between an array of values:
{% for i in 0..10 %}
{{ ['odd', 'even']|cycle(i) }}
{% endfor %}
The array can contain any number of values:
{% set fruits as ['apple', 'orange', 'citrus'] %}
{% for i in 0..10 %}
{{ fruits|cycle(i) }}
{% endfor %}
urlencodeThe urlencode filter URL encodes a given string.
titleThe title filter returns a titlecased version of the value. I.e. words will
start with uppercase letters, all remaining characters are lowercase.
capitalizeThe capitalize filter capitalizes a value. The first character will be
uppercase, all others lowercase.
upperThe upper filter converts a value to uppercase.
lowerThe lower filter converts a value to lowercase.
striptagsThe striptags filter strips SGML/XML tags and replace adjacent whitespace by
one space.
joinThe join filter returns a string which is the concatenation of the strings
in the sequence. The separator between elements is an empty string per
default, you can define it with the optional parameter:
{{ [1, 2, 3]|join('|') }}
{# returns 1|2|3 #}
{{ [1, 2, 3]|join }}
{# returns 123 #}
reverseThe reverse filter reverses an array or an object if it implements the
Iterator interface.
lengthThe length filters returns the number of items of a sequence or mapping, or
the length of a string.
sortThe sort filter sorts an array.
in (new in Twig 0.9.5)Returns true if the value is contained within another one.
{# returns true #}
{{ 1|in([1, 2, 3]) }}
{{ 'cd'|in('abcde') }}
You can use this filter to perform a containment test on strings, arrays, or
objects implementing the Traversable interface.
The in operator is a syntactic sugar for the in filter:
{% if 1 in [1, 2, 3] %}
TRUE
{% endif %}
{# is equivalent to #}
{% if 1|in([1, 2, 3]) %}
TRUE
{% endif %}
range (new in Twig 0.9.5)Returns a list containing a sequence of numbers. The left side of the filter
represents the low value. The first argument of the filter is mandatory and
represents the high value. The second argument is optional and represents the
step (which defaults to 1).
If you do need to iterate over a sequence of numbers:
{% for i in 0|range(10) %}
* {{ i }}
{% endfor %}
The
rangefilter works as the native PHPrangefunction.
The .. operator (see above) is a syntactic sugar for the range filter
(with a step of 1):
{% for i in 0|range(10) %}
* {{ i }}
{% endfor %}
{# is equivalent to #}
{% for i in 0..10 %}
* {{ i }}
{% endfor %}
defaultThe default filter returns the passed default value if the value is
undefined, otherwise the value of the variable:
{{ my_variable|default('my_variable is not defined') }}
keysThe keys filter returns the keys of an array. It is useful when you want to
iterate over the keys of an array:
{% for key in array|keys %}
...
{% endfor %}
escape, eThe escape filter converts the characters &, <, >, ', and " in
strings to HTML-safe sequences. Use this if you need to display text that
might contain such characters in HTML.
Internally,
escapeuses the PHPhtmlspecialcharsfunction.
safeThe safe filter marks the value as safe which means that in an environment
with automatic escaping enabled this variable will not be escaped.
{% autoescape on }
{{ var|safe }} {# var won't be escaped #}
{% autoescape off %}
divisiblebydivisibleby checks if a variable is divisible by a number:
{% if loop.index is divisibleby(3) %}
nonenone returns true if the variable is none:
{{ var is none }}
eveneven returns true if the given number is even:
{{ var is even }}
oddodd returns true if the given number is odd:
{{ var is odd }}
sameassameas checks if a variable points to the same memory address than another
variable:
{% if foo.attribute is sameas(false) %}
the foo attribute really is the `false` PHP value
{% endif %}
Twig can be easily extended. If you are looking for new tags or filters, have a look at the Twig official extension repository: http://github.com/fabpot/Twig-extensions.
