观察者模式

<?php
#观察者模式


/**
观察者模式属于行为模式，是定义对象间的一种一对多的依赖关系，以便当一个对象的状态发生改变时，所有依 赖于它的对象都得到通知并自动刷新。
它完美的将观察者对象和被观察者对象分离。
可以在独立的对象（主体）中维护一个对主体感兴趣的依赖项（观察器）列表。 让所有观察器各自实现公共的 Observer 接口，以取消主体和依赖性对象之间的直接依赖关系。
 */

//具体主题角色
class user implements SplSubject{
    public $lognum;
    public $hobby;
    protected $observers = array();

    public function __construct($hobby){
        $this->lognum = rand(1,10);
        $this->hobby = $hobby;
//	$this->observers = new SplObjectStorage();
        $this->observers = array();
    }

    public function login(){
        $this->notify();
    }
//增加一个新的观察者对象
    public function attach(SplObserver $observer){
//	$this->observers->attach($observer);
        array_push($this->observers,$observer);
    }
//除一个已注册过的观察者对象
    public function detach(SplObserver $observer){
//	$this->observers->detach($observer);
        $index = array_search($observer, $this->observers);
        if ($index === FALSE || ! array_key_exists($index, $this->observers)) {
            return FALSE;
        }

        unset($this->observers[$index]);
        return TRUE;
    }
//通知所有注册过的观察者对象
    public function notify(){
//	$this->observers->rewind();
//	while($this->observers->valid()){
//	$observer = $this->observers->current();
//	$observer->update($this);
//	$this->observers->next();
//	}

        if (!is_array($this->observers)) {
            return FALSE;
        }

        foreach ($this->observers as $observer) {
            $observer->update($this);
        }
        return TRUE;
    }


}

//观察者角色
class secrity implements SplObserver{
    public function update(SplSubject $subject){
        if($subject->lognum <5){
            echo $subject->lognum." < 5";
        }else{
            echo $subject->lognum." >= 5";
        }

    }
}
//观察者角色
class ad implements SplObserver{
    public function update(SplSubject $subject){
        if($subject->hobby == "sport"){
            echo $subject->hobby."我爱运动";
        }else{
            echo "不爱运动哦！";
        }

    }
}


$user = new user("sport1");
$user->attach(new secrity());
$user->attach(new ad());
$user->login();

 

　　

<?php

/**
 * Class Subject
 * 抽象目标类
 */
abstract class Subject
{
    protected $stateNow;
    protected $observers = [];

    public function attach(Observer $observer)
    {
        array_push($this->observers, $observer);
    }

    public function detach(Observer $ob)
    {
        $pos = 0;
        foreach ($this->observers as $viewer) {
            if ($viewer == $ob) {
                array_splice($this->observers, $pos, 1);
            }
            $pos++;
        }
    }

    public function notify()
    {
        foreach ($this->observers as $viewer) {
            $viewer->update($this);
        }
    }
}


/**
 * Class ConcreteSubject
 * 具体目标类
 */
class ConcreteSubject extends Subject
{
    public function setState($state)
    {
        $this->stateNow = $state;
        $this->notify();
    }

    public function getState()
    {
        return $this->stateNow;
    }
}

//抽象观察者
abstract class Observer
{
    abstract public function update(Subject $subject);
}


//具体观察者
class ConcreteObserverDT extends Observer
{
    private $currentState;

    public function update(Subject $subject)
    {
        $this->currentState = $subject->getState();

        echo '<div style="font-size:10px;">'. $this->currentState .'</div>';
    }
}

class ConcreteObserverPhone extends Observer
{
    private $currentState;

    public function update(Subject $subject)
    {
        $this->currentState = $subject->getState();

        echo '<div style="font-size:20px;">'. $this->currentState .'</div>';
    }
}



//使用观察者模式
class Client
{
    public function __construct()
    {
        $sub = new ConcreteSubject();

        $obDT = new ConcreteObserverDT();
        $obPhone = new ConcreteObserverPhone();

        $sub->attach($obDT);
        $sub->attach($obPhone);
        $sub->setState('Hello World');
    }
}

$worker = new Client();