Asset bundles

Assets in Yii2 are managed through an asset bundle. An asset bundle in Yii2 is simply a class that declares all the assets that we want to use in our application, and resides within the assets/ directory of our application, usually within the AppAsset.php file that declares an AppAsset class that extends yii\web\AssetBundle. Since our default application comes within a pre-defined AppAsset class, let's take a look at what is already defined in that file.

<?php

namespace app\assets;
use yii\web\AssetBundle;

class AppAsset extends AssetBundle
{
    public $basePath = '@webroot';
    public $baseUrl = '@web';

    public $css = [
        'css/site.css',
        '//ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js'
    ];

    public $js = [ ];

    public $depends = [
        'yii\web\YiiAsset',
        'yii\bootstrap\BootstrapAsset',
    ];
}

Our example asset bundle file declares several public properties...