dongxianglun5163 2013-11-03 18:29
浏览 53
已采纳

PHP OOP:从子级调用方法父级

I've this class

class Controller {

    protected $f3;
    protected $db;


    function __construct()
    {

        $f3=Base::instance();

    $db=new \DB\SQL('mysql:host=62.xxx;port=3306;dbname=Sqlxxx','xxxx','xxxxx');

    $this->f3=$f3;
    $this->db=$db;

    $this->db->exec('SET CHARACTER SET utf8');
    $this->db->exec('SET time_zone = \'+00:00\'');

    }
}

and his child

class WebController extends Controller {
    public function login()
    {
        $db=new \DB\SQL('mysql:host=62.xxx;port=3306;dbname=Sqlxxx','xxxx','xxxxx');
        $user = new \DB\SQL\Mapper($db, 'users');
        $auth = new \Auth($user, array('id'=>'username', 'pw'=>'password'));
    }
 }

I need another $db object in WebController, you can note that for the moment i did duplicate code.

How i can recall the $db from parent without duplicate code? I did try

$db = parent::__construct();

without luck. Thank you

  • 写回答

2条回答 默认 最新

  • dongzhao2725 2013-11-03 19:15
    关注

    You should explicitly declare your constructor as public as a matter of good practice.

    You are not overriding the constructor in the child and so the parent constructor is used.

    The child inherits the parents properties which are protected.

    Therefore you can use $this->db to access the database object of the parent.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
  • dongyan6503 2013-11-03 18:36
    关注

    You should extract creaing $db to method (createConnection) ie.:

    class Controller {
        protected $f3;
        protected $db;
    
    
        function __construct()
        {
            $this->f3=Base::instance();
            $this->db=$this->createConnection();  
        }
        protected function createConnection() {
            $db = new \DB\SQL('mysql:host=62.xxx;port=3306;dbname=Sqlxxx','xxxx','xxxxx');
            $db->exec('SET CHARACTER SET utf8');
            $db->exec('SET time_zone = \'+00:00\'');
            return $db;
        }
    }
    

    And then you can use extracted method:

    class WebController extends Controller {
        public function login()
        {
            $db=$this->createConnection();
            $user = new \DB\SQL\Mapper($db, 'users');
            $auth = new \Auth($user, array('id'=>'username', 'pw'=>'password'));
        }
    }
    

    Or use connection created via constructor

    class WebController extends Controller {
        public function login()
        {
            $user = new \DB\SQL\Mapper($this->db, 'users');
            $auth = new \Auth($user, array('id'=>'username', 'pw'=>'password'));
        }
    }
    
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 grafna发送告警信息
  • ¥15 51单片机,LCD屏幕内容修改
  • ¥20 Ida Pro动态调试
  • ¥15 TensorFlow深度学习拓展项目
  • ¥20 springboot博客系统
  • ¥15 MICE包多重插补后数据集汇总导出
  • ¥15 一道算法分析问题(关于3-MSAT)
  • ¥15 C++ FLUENT 化学反应速率 编写困难
  • ¥15 Python嵌套交叉验证
  • ¥15 linuxkit+elasticsearch