PHP观察者模式

<?php

interface IObserverable{
    function register(IObserver $obj);
    function unregister(IObserver $obj);
}

interface IObserver{
    function show(array $feed);
}


abstract class FeedObserverable implements IObserverable{
    private $_observer_container = array();
    public function register(IObserver $obj){
        if(!in_array($obj,$this->_observer_container))
            array_push($this->_observer_container,$obj);
    }
    public function unregister(IObserver $obj){
        unset($this->_observer_container[$obj]);
    }
    public function notify($feed){
        foreach($this->_observer_container as $observer){
            $observer->show($feed);
        }
    }
}
/**
 *html观察者
 */
class htmlView implements IObserver{
    public function show(array $feed){
        print_r($feed);
    }
}
/**
 *json观察者
 */
class jsonView implements IObserver{
    public function show(array $feed){
        echo json_encode($feed);
    }
}

/**
 *主业务
 */
class feedModel extends FeedObserverable{
    private $_feed = array();
    public function addNewFeed(array $feed){
        //todo
        //更新视图
        $this->notify($feed);
    }
}

//调用方法
$model = new FeedModel();
$feed = array('title'=>'test','content'=>'this is a new feed!');
$model->register(new jsonView());
$model->register(new htmlView());
$model->addNewFeed($feed);
?>