/**
  * @return ActiveQuery
  */
 public function getCategory()
 {
     return $this->hasOne(CategoryModels::className(), ['id' => 'category_id']);
 }
 /**
  * This action render the index page.
  * @return string
  */
 public function actionIndex()
 {
     $categories = CategoryModels::find()->with(['forums'])->orderBy('display_position')->all();
     return $this->render('index', ['categories' => $categories]);
 }