PHP-laravel 的 模型多条件搜索

public function ScreenClassBooksMessage($type='',$font_number='',$status='',$attr)
{
     $data = $this->where('Attr',$attr)->where('state',1)
            ->when($status!='', function ($query) use ($status) {
                    return $query->where('BookStatus', $status);
            })
            ->when($type!='', function ($query) use ($type) {
                    return $query->where('category_name', $type);
            })
            ->when($font_number!='', function ($query) use ($font_number) {
             return $query->where('word_count', $font_number);
            })
            ->select('Id','Name','pic','category_name','Author','Introduce','BookStatus','Attr')
            ->paginate(10)->toArray();
    return $data;
}