public function actionItems($langId, $containerId)
    {
        $items = Nav::find()
            ->where(['nav_container_id' => $containerId, 'is_offline' => false, 'ni.lang_id' => $langId, 'is_deleted' => false])
            ->joinWith(['navItems ni'])
            ->asArray()
            ->all();
        $result = [];

        foreach ($items as $item) {
            // rename from navItems to item
            $item['item'] = reset($item['navItems']);
            unset($item['navItems']);
            $result[$item['parent_nav_id']][] = $item;
        }

        return $result;
    }