PHP设计模式实例之观察者模式

<?php
//被察者抽象类
class Observed implements SplSubject{
    protected $_name;
    protected $_observers;

    //实例化,生成一个观察者对象
    public function __construct(){
        $this->_observers = new SplObjectStorage();
    }

    // 添加观察者对象
    public function attach(SplObserver $observer){
        $this->_observers->attach($observer);
    }

    //删除观者对象
    public function detach(SplObserver $observer){
        $this->_observers->detach($observer);
    }

    //通知消息
    public function notify(){
        foreach($this->_observers as $observer){
            $observer->showMessage($this);
        }
    }

    //普通方法: 设置值
    public function setName($name){
        $this->_name = $name;
        $this->notify();
    }

    //普通方法: 获取值
    public function getName(){
        return $this->_name;
    }

    //普通方法:设置年龄
    public function setAge($age){
        $this->age = $age;
        foreach($this->_observers as $observer){
            $observer->showAge($this->_name,$this->age);
        }
    }

}

// 观察者抽象类
class Observer implements SplObserver{

    //显示消息提示
    public function showMessage(SplSubject $obj){
        $user = $obj->getName();
        if($user==='admin'){
            echo '您好, ',$user,'欢迎您进入管理后台<br/>';
        }else{
            echo "你好, '$user' 你已经被添加到了用户列表<br/>";
        }
    }
    //这是继承父类的抽象方法
    public function update(SplSubject $subject) {}

    //显示个人年龄
    public function showAge($name,$age){
        echo "<script>alert('$name 的年龄是: $age')</script>";
    }
}

$subject = new Observed();  //生成一个被观察者对象
$observer = new Observer(); //生成一个观察者对象
$subject->attach($observer);//把观察者传入到被观察中去
$subject->setName('张三'); //调用 setName 方法
/*
 * 通过面的 setName 就会调用  $this->notify();
* 通过调用  $this->notify()就会调用 $observer->showMessage($this)方法,
* 即每个观察者对象的 showMessage($obj)方法;
*/
$subject->setName('admin');
$subject->setAge(24);
?>

<?php
//观察者模式
interface Subject
{
public function Attach($Observer); //添加观察者
public function Detach($Observer); //踢出观察者
public function Notify(); //满足条件时通知观察者
public function SubjectState($Subject); //观察条件
}
class Boss Implements Subject
{
public $_action;
private $_Observer;
public function Attach($Observer)
{
$this->_Observer[] = $Observer;
}
public function Detach($Observer)
{
$ObserverKey = array_search($Observer, $this->_Observer);
if($ObserverKey !== false)
{
unset($this->_Observer[$ObserverKey]);
}
}
public function Notify()
{
foreach($this->_Observer as $value )
{
$value->Update();
}
}
public function SubjectState($Subject)
{
$this->_action = $Subject;
}
}
abstract class Observer
{
protected $_UserName;
protected $_Sub;
public function __construct($Name,$Sub)
{
$this->_UserName = $Name;
$this->_Sub = $Sub;
}
public abstract function Update(); //接收通过方法
}
class StockObserver extends Observer
{
public function __construct($name,$sub)
{
parent::__construct($name,$sub);
}
public function Update()
{
echo $this->_Sub->_action.$this->_UserName." 你赶快跑...";
}
}
$huhansan = new Boss(); //被观察者
$gongshil = new StockObserver("三毛",$huhansan); //初始化观察者
$huhansan->Attach($gongshil); //添加一个观察者
$huhansan->Attach($gongshil); //添加一个相同的观察者
$huhansan->Detach($gongshil); //踢出基中一个观察者
$huhansan->SubjectState("警察来了"); //达到满足的条件
$huhansan->Notify(); //通过所有有效的观察者
?>

<?php
//php观察者模式
//整理 脚本学堂 www.jbxue.com
interface Message {
   static function getType();
};

interface Observer {
   function notifyMsg(Message $msg);
};

class Subject {
   private $observers = Array();

   public function registerObserver(Observer $observer, $msgType) {
    $this->observers[$msgType][] = $observer;   // wyh?
   }

   private function notifyMsg(Message $msg) {
    @$observers = $this->observers[$msg->getType()];
    if (!$observers) {
     return;
    }

    foreach ($observers as $observer) {
     $observer->notifyMsg($msg);
    }
   }

   public function someMethod() {
           sleep(1);
          $this->notifyMsg(new HelloMessage("Michael"));
        }
}
class HelloMessage implements Message {
   private $name;

   public function __construct($name) {
    $this->name = $name;
   }

   public function getMsg() {
    return "Hello,$this->name!";
   }

   static function getType() {
    return "HELLO_TYPE";
   }
}

class SubObserver implements Observer {
   public function notifyMsg(Message $msg) {
    if ($msg instanceof HelloMessage) {
     echo $msg->getMsg();
    }
   }
}

$subject = new Subject();
    $observer = new SubObserver();
    $subject->registerObserver($observer, HelloMessage::getType());
    $subject->someMethod();
?>