public function updateViewCounter()
    {
        $userId = Yii::$app->user->id;
        $viewCount = $this->viewCount;

        if (!empty($viewCount)) {
            $viewCount->updateCounters(['count' => 1]);
        } else {
            $viewCount = new ArticleViewCount();
            $viewCount->article_id = $this->id;
            $viewCount->viewer_id = $userId;
            $viewCount->save();
            $viewCount->updateCounters(['count' => 1]);
        }

        return $viewCount;
    }