PHP设计模式之观察者模式定义与用法示例

<?php
/**
 * interface observable
 * define a observable interface
 * @author jichao.wang
 */
interface observable
{
  function attach(observer $observer);
  function detach(observer $observer);
  function notify();
}
/**
 * class login
 * @author jichao.wang
 */
class login implements observable
{
  private $observers;
  public $status;
  public $ip;
  const login_access = 1;
  const login_wrong_pass = 2;
  const login_user_unknown = 3;
  function __construct()
  {
    $this->observers = array();
  }
  /**
   * @param observer $observer
   * @author jichao.wang
   * attach a observer
   */
  function attach(observer $observer)
  {
    $this->observers[] = $observer;
  }
  /**
   * @param observer $observer
   * @author jichao.wang
   * detach a observer
   */
  function detach(observer $observer)
  {
    $newobservers = array();
    foreach ($this->observers as $key => $obs) {
      if ($obs !== $observer) {
        $newobservers[] = $obs;
      }
    }
    $this->observers = $newobservers;
  }
  /**
   * @author jichao.wang
   * handle observer notify
   */
  function notify()
  {
    foreach ($this->observers 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;
  }
}
/**
 * interface observer
 * @author jichao.wang
 */
interface observer {
  function update(observable $observable);
}
/**
 * class emailobserver
 * @author jichao.wang
 */
class emailobserver implements observer {
  function update (observable $observable) {
    $status = $observable->getstatus();
    if($status == login::login_access){
//      $this->sendmail('用户ip:'.$observable->ip.'登陆成功!');
      echo __class__.'用户ip:'.$observable->ip.'登陆成功!'.'------------------';
    }
    if($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:'.$observable->ip.'登陆失败，密码错误!'.'------------------';
    }
    if($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:'.$observable->ip.'登陆失败，无此用户!'.'------------------';
    }
  }
}
/**
 * class phoneobserver
 * @author jichao.wang
 */
class phoneobserver implements observer {
  function update (observable $observable) {
    $status = $observable->getstatus();
    if($status == login::login_access){
//      $this->sendmail('用户ip:'.$observable->ip.'登陆成功!');
      echo __class__.'用户ip:'.$observable->ip.'登陆成功!'.'------------------';
    }
    if($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:'.$observable->ip.'登陆失败，密码错误!'.'------------------';
    }
    if($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:'.$observable->ip.'登陆失败，无此用户!'.'------------------';
    }
  }
}
class abcobserver implements observer {
  function update (observable $observable) {
    $status = $observable->getstatus();
    if($status == login::login_access){
//      $this->sendmail('用户ip:'.$observable->ip.'登陆成功!');
      echo __class__.'用户ip:'.$observable->ip.'登陆成功!'.'------------------';
    }
    if($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:'.$observable->ip.'登陆失败，密码错误!'.'------------------';
    }
    if($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:'.$observable->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
$login->attach(new emailobserver());
//实现发验证码观察者
$login->attach(new phoneobserver());
//实现其他观察者
$login->attach(new abcobserver());
//开始登陆
$login->handlelogin();
?>