/**
  * @param $id
  * @return string
  */
 public function actionView($id)
 {
     /* @var SiteModels $forum */
     $forum = SiteModels::findOne(['id' => $id]);
     $query = TopicModels::find()->where(['forum_id' => $id])->orderBy(['sticked' => SORT_DESC])->addOrderBy(['last_post_created_at' => SORT_DESC]);
     $dataProvider = new ActiveDataProvider(['query' => $query, 'pagination' => ['forcePageParam' => false, 'pageSizeLimit' => false, 'defaultPageSize' => Yii::$app->config->get('display_topics_count')]]);
     $topics = $dataProvider->getModels();
     return $this->render('view', ['dataProvider' => $dataProvider, 'forum' => $forum, 'topics' => $topics]);
 }