/**
* Add sort for foreign key attribute
* If you override this method, remember to call parent implementation.
* @param ActiveQuery $query search query
* @param ActiveDataProvider $dataProvider data results
*/
public function addSort($query, $dataProvider)
{
if ($this->modelName !== null && !$this->oneToMany) {
$query->joinWith($this->relationName);
$relationClass = $this->relationClass;
$dataProvider->sort->attributes[$this->relationParameter] = ['asc' => [$relationClass::tableName() . '.' . $this->modelName => SORT_ASC], 'desc' => [$relationClass::tableName() . '.' . $this->modelName => SORT_DESC]];
}
}
