public function rules()
{
return [['url', 'required'], ['url', 'unique'], ['url', 'length', 'max' => 250], ['changefreq', 'length', 'max' => 20], ['priority', 'numerical'], ['status', 'numerical', 'integerOnly' => true], ['id, url, changefreq, priority, status', 'safe', 'on' => 'search']];
}