public function actionRss()
{
    $dataProvider = new ActiveDataProvider([
        'query' => Post::find()->with(['user']),
        'pagination' => [
            'pageSize' => 10
        ],
    ]);
    
    $response = Yii::$app->getResponse();
    $headers = $response->getHeaders();
    
    $headers->set('Content-Type', 'application/rss+xml; charset=utf-8');
    
    $response->content = \Zelenin\yii\extensions\Rss\RssView::widget([
        'dataProvider' => $dataProvider,
        'channel' => [
            'title' => Yii::$app->name,
            'link' => Url::toRoute('/', true),
            'description' => 'Posts ',
            'language' => Yii::$app->language
        ],
        'items' => [
            'title' => function ($model, $widget) {
                    return $model->name;
                },
            'description' => function ($model, $widget) {
                    return StringHelper::truncateWords($model->content, 50);
                },
            'link' => function ($model, $widget) {
                    return Url::toRoute(['post/view', 'id' => $model->id], true);
                },
            'author' => function ($model, $widget) {
                    return $model->user->email . ' (' . $model->user->username . ')';
                },
            'guid' => function ($model, $widget) {
                    $date = \DateTime::createFromFormat('Y-m-d H:i:s', $model->updated_at);
                    return Url::toRoute(['post/view', 'id' => $model->id], true) . ' ' . $date->format(DATE_RSS);
                },
            'pubDate' => function ($model, $widget) {
                    $date = \DateTime::createFromFormat('Y-m-d H:i:s', $model->updated_at);
                    return $date->format(DATE_RSS);
                }
        ]
    ]);
}