phpデザインモードDecorator(デコレーションモード)

 
  
/** 
  
*      
  
* 
  
*                  ,                   
  
*/ 
  
header("Content-type:text/html;charset=utf-8"); 
  
abstract class MessageBoardHandler 
  
{ 
  
public function __construct(){} 
  
abstract public function filter($msg); 
  
} 
  
 
  
class MessageBoard extends MessageBoardHandler 
  
{ 
  
public function filter($msg) 
  
{ 
  
return "         |".$msg; 
  
} 
  
} 
  
 
  
$obj = new MessageBoard(); 
  
echo $obj->filter("         
"); 
  
 
  
// ---           ---- 
  
class MessageBoardDecorator extends MessageBoardHandler 
  
{ 
  
private $_handler = null; 
  
 
  
public function __construct($handler) 
  
{ 
  
parent::__construct(); 
  
$this->_handler = $handler; 
  
} 
  
 
  
public function filter($msg) 
  
{ 
  
return $this->_handler->filter($msg); 
  
} 
  
} 
  
 
  
//   html 
  
class HtmlFilter extends MessageBoardDecorator 
  
{ 
  
public function __construct($handler) 
  
{ 
  
parent::__construct($handler); 
  
} 
  
 
  
public function filter($msg) 
  
{ 
  
return "   HTML  |".parent::filter($msg);; //    HTML                      
  
} 
  
} 
  
 
  
//       
  
class SensitiveFilter extends MessageBoardDecorator 
  
{ 
  
public function __construct($handler) 
  
{ 
  
parent::__construct($handler); 
  
} 
  
 
  
public function filter($msg) 
  
{ 
  
return "      |".parent::filter($msg); //                           
  
} 
  
} 
  
 
  
$obj = new HtmlFilter(new SensitiveFilter(new MessageBoard())); 
  
echo $obj->filter("         !
");