public function actionRecalc()
 {
     $post_counts = array();
     $ids = Yii::$app->session->get('ids');
     for ($i = 0; $i < count($ids); $i++) {
         $post_counts[$i] = $_POST['count' . $ids[$i]];
     }
     $cart = new Cart();
     $cart->recalc($ids, $post_counts);
     return $this->redirect(Yii::$app->request->referrer);
 }