本文实例讲述了PHP设计模式之观察者模式定义与用法。分享给大家供大家参考，具体如下：
<?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();
?>
运行结果：
EmailObserver用户ip:41登陆失败，无此用户!------------------PhoneObserver用户ip:41登陆失败，无此用户!------------------AbcObserver用户ip:41登陆失败，无此用户!------------------
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希望本文所述对大家PHP程序设计有所帮助。
