PHP观察者模式实例分析【对比JS观察者模式】

2024-05-05 00:09:11

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本文实例讲述了PHP观察者模式。分享给大家供大家参考，具体如下：

1.用js实现观察者模式

<!DOCTYPE html><html><head>    <title></title>    <style type="text/css">    div{width: 100px;height: 100px;border: 1px #999 solid;margin-bottom: 5px;}    </style></head><body><!--我们让div对象观察select的变化，selecte变化就会通知这个2个对象，并引起这2个对象的变化，实现观察者模式。 --> <h1>用观察者模式切换页面风格</h1> <select>     <option value="male">男式风格</option>     <option value="female">女士风格</option> </select> <button onclick="t1()">观察学习区</button> <button onclick="t2()">不观察学习区</button> <div id="content">我是内容</div> <div id="ad">我是广告</div> <div id="study">学习</div></body><script type="text/javascript">    var sel = document.getElementsByTagName('select')[0];    sel.observers = {};    sel.attach = function(key,obj){        this.observers[key] = obj;    }    sel.detach = function(key){        delete this.observers[key];    }    sel.onchange = sel.notify = function(){        for(var key in this.observers){            this.observers[key].update(this);        }    }    //客户端    var content = document.getElementById('content');    var ad = document.getElementById('ad');    content.update = function(ob){        if (ob.value == 'male') {            this.style.backgroundColor = 'gray';        }else if(ob.value == 'female'){            this.style.backgroundColor = 'pink';        }    }    ad.update = function(ob){        if (ob.value == 'male') {            this.innerHTML = '汽车';        }else if(ob.value == 'female'){            this.innerHTML = '减肥';        }    }    //让content观察select的变化    sel.attach('content',content);    sel.attach('ad',ad);    //新增监听study区    var study = document.getElementById('study');    study.update = function(ob){        if (ob.value == 'male') {            this.innerHTML = '学习计算机';        }else if(ob.value == 'female'){            this.innerHTML = '学习美容';        }    }    sel.attach('study',study);    function t1(){        sel.attach('study',study);    }    function t2(){        sel.detach('study');    }</script></html>

2.用php实现观察模式

<?php//php实现观察者//php5中提供观察者observer和被观察者subject的接口class User implements SplSubject{    public $lognum;    public $hobby;    protected $observers = null;    public function __construct($hobby)    {        $this->lognum = rand(1,10);        $this->hobby = $hobby;        $this->observers = new SplObjectStorage();    }    public function login()    {        //操作session等        $this->notify();    }    public function attach(SPLObserver $observer)    {        $this->observers->attach($observer);    }    public function detach(SPLObserver $observer)    {        $this->observers->detach($observer);    }    public function notify()    {        $this->observers->rewind();        while ($this->observers->valid()) {            $observer = $this->observers->current();            $observer->update($this);            $this->observers->next();        }    }}//用户安全登录模块class Safe implements SPLObserver{    public function update(SplSubject $subject)    {        if ($subject->lognum < 3) {            echo '这是第' . $subject->lognum . '次安全登录<br>';        }else{            echo '这是第' . $subject->lognum . '次登录，异常<br>';        }    }}//广告模块class Ad implements SPLObserver{    public function update(SplSubject $subject)    {        if ($subject->hobby == 'sports') {            echo '英超开始啦<br>';        }else{            echo '好好学习<br>';        }    }}//实施观察// $user = new User('sports');$user = new User('study');$user->attach(new Safe());$user->attach(new Ad());$user->login();//登录

希望本文所述对大家PHP程序设计有所帮助。

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