/**
* Action method for auto completion sections by the given parent category.
* @param integer $id of the category to be used to auto complete sections.
* @return string|Response action method execution result.
*/
public function actionSections($id)
{
$sections = Section::findAll(['category_id' => $id]);
$items = array_merge(['(choose section)'], ArrayHelper::map($sections, 'id', 'title'));
return Html::renderSelectOptions(null, $items);
}
