Template Syntax

The best resource to learn Twig basics is its official documentation you can find at twig.sensiolabs.org. Additionally there are Yii-specific syntax extensions described below.

Method and function calls

If you need result you can call a method or a function using the following syntax:

{% set result = my_function({'a' : 'b'}) %}
{% set result = myObject.my_function({'a' : 'b'}) %}

If you need to echo result instead of assigning it to a variable:

{{ my_function({'a' : 'b'}) }}
{{ myObject.my_function({'a' : 'b'}) }}

In case you don't need result you should use void wrapper:

{{ void(my_function({'a' : 'b'})) }}
{{ void(myObject.my_function({'a' : 'b'})) }}

Setting object properties

There's a special function called set that allows you to set property of an object. For example, the following in the template will change page title:

{{ set(this, 'title', 'New title') }}

Importing widgets namespaces and classes

You can import additional classes and namespaces right in the template:

Namespace import:
{{ use('/app/widgets') }}

Class import:
{{ use('/yii/widgets/ActiveForm') }}

Aliased class import:
{{ use({'alias' : '/app/widgets/MyWidget'}) }}

Please refer to Layouts and Widgets for additional information.

Importing other classes

In most cases, except widgets and assets, you have to import classes via globals.

For example this code prints nothing:

{{ use('yii/helpers/Url') }}
<h1>{{ Url.base(true) }}</h1>

and this code also prints nothing:

{{ use ('app/models/MyClass') }}  
{{ MyClass.helloWorld() }}

You have add these classes to globals:

// ....
'view' => [
    'class' => 'yii\web\View',
    'renderers' => [
        'twig' => [
            'class' => 'yii\twig\ViewRenderer',
            'cachePath' => '@runtime/Twig/cache',
            'options' => [
                'auto_reload' => true,
            ],
            'globals' => [
                'Url' => ['class' => '\yii\helpers\Url'],
                'MyClass' => ['class' => '\frontend\models\MyClass'],
            ],
        ],
    ],
],
// ....

Only then you can use classes such way: <h1>{{ Url.base(true) }}</h1> {{ MyClass.helloWorld() }}

Referencing other templates

There are two ways of referencing templates in include and extends statements:

{% include "comment.twig" %}
{% extends "post.twig" %}

{% include "@app/views/snippets/avatar.twig" %}
{% extends "@app/views/layouts/2columns.twig" %}

In the first case the view will be searched relatively to the current template path. For comment.twig and post.twig that means these will be searched in the same directory as the currently rendered template.

In the second case we're using path aliases. All the Yii aliases such as @app are available by default.

You can also use render method inside a view: {{ this.render('comment.twig', {'data1' : data1, 'data2' : data2}) | raw }}

Assets

Assets could be registered the following way (since 2.0.4):

{{ register_asset_bundle('yii/web/JqueryAsset') }}

There's a bit more verbose syntax used previously:

{{ use('yii/web/JqueryAsset') }}
{{ register_jquery_asset() }}

In the call above register identifies that we're working with assets while jquery_asset translates to JqueryAsset class that we've already imported with use.

URLs

There are two functions you can use for building URLs:

<a href="{{ path(['blog/view'], {'alias' : post.alias}) }}">{{ post.title }}</a>
<a href="{{ url(['blog/view'], {'alias' : post.alias}) }}">{{ post.title }}</a>

path generates relative URL while url generates absolute one. Internally both are using \yii\helpers\Url::to.

Additional variables

Within Twig templates the following variables are always defined:

  • app, which equates to \Yii::$app
  • this, which equates to the current View object

Blocks

You can set blocks the following way:

{{ void(this.beginBlock('block1')) }}
now, block1 is set
{{ void(this.endBlock()) }}

Then, in the layout view, render the blocks:

{{ this.blocks['block1'] }}