PHP使用标准库spl实现的观察者模式示例

?php
/**
 * Created by PhpStorm.
 * User: evolution
 * Date: 14-12-27
 * Time: 下午5:50
 */
class Login implements SplSubject {
  private $storage;
  public $status;
  public $ip;
  const LOGIN_ACCESS = 1;
  const LOGIN_WRONG_PASS = 2;
  const LOGIN_USER_UNKNOWN = 3;
  function __construct(){
    $this->storage = new SplObjectStorage();
  }
  function attach (SplObserver $observer) {
    $this->storage->attach($observer);
  }
  function detach(SplObserver $observer){
    $this->storage->detach($observer);
  }
  function notify(){
    foreach ($this->storage as $obs) {
      $obs->update($this);
    }
  }
  /**
   * @author jichao.wang
   * 执行登陆
   */
  function handleLogin()
  {
    $ip = rand(1,100);
    switch (rand(1, 3)) {
      case 1:
        $this->setStatus(self::LOGIN_ACCESS, $ip);
        $ret = true;
        break;
      case 2:
        $this->setStatus(self::LOGIN_WRONG_PASS, $ip);
        $ret = false;
        break;
      case 3:
        $this->setStatus(self::LOGIN_USER_UNKNOWN, $ip);
        $ret = false;
        break;
    }
    /**
     * handle event
     */
    $this->notify();
    return $ret;
  }
  /**
   * @param $status
   * @author jichao.wang
   * set login status
   */
  function setStatus($status,$ip)
  {
    $this->status = $status;
    $this->ip = $ip;
  }
  /**
   * @return mixed
   * @author jichao.wang
   * get login status
   */
  function getStatus()
  {
    return $this->status;
  }
}
/**
 * 只针对登陆的贯观察者
 * Class LoginObserver
 */
abstract class LoginObserver implements SplObserver {
  private $login;
  function __construct(Login $login){
    $this->login = $login;
    $login->attach($this);
  }
  /**
   * 对外统一的访问点
   * @param SplSubject $subject
   */
  function update( SplSubject $subject ){
    if($subject === $this->login){
      $this->doUpdate($subject);
    }
  }
  abstract function doUpdate( Login $login );
}
/**
 * Class EmailObserver
 */
class EmailObserver extends LoginObserver{
  //不同功能的观察者实现不同的功能
  function doUpdate( Login $login ){
    $status = $login->getStatus();
    if($status == Login::LOGIN_ACCESS){
//      $this->sendMail('用户ip:'.$observable->ip.'登陆成功!');
      echo __CLASS__.'用户ip:'.$login->ip.'登陆成功!'.'------------------';
    }
    if($status == Login::LOGIN_WRONG_PASS){
//      $this->sendMail('用户ip:'.$observable->ip.'登陆失败，密码错误!');
      echo __CLASS__.'用户ip:'.$login->ip.'登陆失败，密码错误!'.'------------------';
    }
    if($status == Login::LOGIN_USER_UNKNOWN){
//      $this->sendMail('用户ip:'.$observable->ip.'登陆失败，无此用户!');
      echo __CLASS__.'用户ip:'.$login->ip.'登陆失败，无此用户!'.'------------------';
    }
  }
}
//实例化登陆信息
$login = new Login();
//实现发邮件观察者
new EmailObserver($login);
//开始登陆
$login->handleLogin();