4.3、php观察者实现

SplSubject接口 和SplObserver接口
其中SplSubject为被观察者
SplObserver为观察者

//被观察者
class Login implements  SplSubject
{
    public $splobservers = null;
    public $times = 0;
    public function __construct()
    {
        $this->times = mt_rand(1, 9);
        $this->splobservers = new SplObjectStorage();
    }
    public function attach(SplObserver $SplObserver)
    {
        $this->splobservers->attach($SplObserver);
    }
    public function detach(SplObserver $SplObserver)
    {
        $this->splobservers->detach($SplObserver);
    }
    public function notify()
    {
        foreach($this->splobservers as $v)
        {
            $v->update($this);
        }
    }
    public function login()
    {
        $this->notify();
    }
}


//观察者
class User implements  SplObserver
{
    public function update(SplSubject $splsubject)
    {
        echo '该用户登陆了'.$splsubject->times.'次';
    }
}


$user = new User();
$login = new Login();
$login->attach($user);
$login->login();