[PHP知识库]php观察者模式，核心是把客户元素(观察者)从一个中心类(主体)中分离出来

<?php
/*接口，在子类中实现方法功能*/
interface Observable{
	function attach(Observer $observer);
	function detach(Observer $observer);
	function notify();
}
/*主体类，具体功能的实现，handlerLogin实现登陆，用notfity()实现历遍观察者对象，主体通过观attach()添加观察者对象,detach()方法分离，*/
class Login implements Observable{
	private $observers;
	const LOGIN_ACCESS=1;
	const LOGIN_WRONG_PASS=2;
	const LOGIN_USER_UNKNOWN=3;
	private $status=array();
	function handlerLogin($user,$pass,$ip){
		switch(rand(1,3)){
			case 1:
			$this->setStatus(self::LOGIN_ACCESS,$user,$ip);
			$ret=true;
			break;
			case 2:
			$this->setStatus(self::LOGIN_WRONG_PASS,$user,$ip);
			$ret=false;
			break;
			case 3:
			$this->setStatus(self::LOGIN_USER_UNKNOWN,$user,$ip);
			$ret=false;
			break;
		}
		$this->notify();
		return $ret;
	}
	private function setStatus($status,$user,$ip){
		$this->status=array($status,$user,$ip);
	}
	function getStatus(){
		return $this->status;
	}
	function attach(Observer $observer){
		$this->observers[]=$observer;
	}
	function detach(Observer $observer){
		$newobservers=array();
		foreach($this->observers as $obs){
			if(($obs !==$observer)){
				$newobservers[]=$obs;
			}
		}
		$this->observers=$newobservers;
	}
	function notify(){
		foreach($this->observers as $obs){
			$obs->update($this);
		}
	}
}

interface Observer{
	function update(Observable $observable);
}
abstract class LoginObserver implements Observer{
	private $login;
	function __construct(Login $login){
		$this->login=$login;
		$login->attach($this);
	}
	function update(Observable $observable){
		if($observable===$this->login){
			$this->doUpdate($observable);
		}
	}
	abstract function doUpdate(Login $login);
}

class SecurityMonitor extends LoginObserver{
	function doUpdate(Login $login){
		$status=$login->getStatus();
		if($status[0]==Login::LOGIN_USER_UNKNOWN){
			print __CLASS__.": \tsending mail to sysadmin\n <br>";
		}
	}
}
class GeneralLogger extends LoginObserver{
	function doUpdate(Login $login){
		$status=$login->getStatus();
		if($status[0]==Login::LOGIN_WRONG_PASS){
			print __CLASS__.": \t 记录登陆日志数据 <br>";
		}
	}
}
class PartnershipTool extends LoginObserver{
	function doUpdate(Login $login){
		$status=$login->getStatus();
		if($status[0]==Login::LOGIN_USER_UNKNOWN){
			print __CLASS__." \t 检查IP地址，匹配列表设置cookie <br>";
		}
	}
}
$login=new Login();

new SecurityMonitor($login);
new GeneralLogger($login);
new PartnershipTool($login);
$login->handlerLogin("xiaowei","fdfd","123");

?>