ArticleIndex.php

<?php
namespace yiiunit\data\ar\sphinx;

class ArticleIndex extends ActiveRecord
{
    public $custom_column;

    public static function indexName()
    {
        return 'yii2_test_article_index';
    }

    public function getSource()
    {
        return $this->hasOne(ArticleDb::className(), ['id' => 'id']);
    }

    public function getTags()
    {
        return $this->hasMany(TagDb::className(), ['id' => 'tag']);
    }

    public function getSnippetSource()
    {
        return $this->source->content;
    }

    public static function createQuery($config = [])
    {
        $config['modelClass'] = get_called_class();

        return new ArticleIndexQuery($config);
    }
}