PHP 组件注册的例子

 <?php
 namespace  Test;

 abstract class Plugin
 {
     protected $pluginName = null;

     abstract public function action();

     function toString()
     {
         return $this->pluginName;
     }
 }

 class HandPlugin extends Plugin
 {
     protected $pluginName ;

     function __construct($name = 'Hand')
     {
         $this->pluginName = $name;
     }

     public function action()
     {
         // TODO: Implement action() method.
         echo 'Raise your hand!' ."\n";
     }
 }

 class FootPlugin extends Plugin
 {
     protected $pluginName ;

     function __construct($name = 'Foot')
     {
         $this->pluginName = $name;
     }

     public function action()
     {
         // TODO: Implement action() method.
         echo 'Put down your foot!' ."\n";
     }
 }

 class People
 {
     protected $bodyPlugin = array();
     protected $giveName = null;

     public function __construct($name ='Fully Man')
     {
         $this->giveName = $name;
     }

     public function register(Plugin $plugin)
     {
         if(!isset($this->bodyPlugin[$plugin->toString()]))
         {
             $this->bodyPlugin[$plugin->toString()] = $plugin;
         }
         else
         {
             return true;
         }
     }

     public function unRegister(Plugin $plugin)
     {
         if(isset($this->bodyPlugin[$plugin->toString()]))
         {
             unset($this->bodyPlugin[$plugin->toString()]);
         }
         return true;
     }

     public function doBodyAction()
     {
         if(empty($this->bodyPlugin))
         {
             echo 'Nothing to show!' ."\n";
             return false;
         }

         echo $this->giveName. " will do :\n";
         foreach($this->bodyPlugin as $name => $plugin)
         {
             echo $name. ": " ;
             echo $plugin->action();
         }
     }
 }

 $handPlugin = new HandPlugin();
 $footPlugin = new FootPlugin();
 $people = new People();

 $people->register($handPlugin);
 $people->register($footPlugin);

 $people->doBodyAction();