class Article{
  protected $content;
  public function __construct($info){
    $this->content = $info;
  }
}
class editor_A extends Article{
  public function __construct(Article $obj){
    $this->content = $obj->content . '<br/>' . '编辑A新写的内容';
  }
  public function decorator(){
    return $this->content;
  }
}
class editor_B extends Article{
  public function __construct(Article $obj){
    $this->content = $obj->content . '<br/>' . '编辑B新写的内容';
  }
  public function decorator(){
    return $this->content;
  }
}
class editor_C extends Article{
  public function __construct(Article $obj){
    $this->content = $obj->content . '<br/>' . '编辑C新写的内容';
  }
  public function decorator(){
    return $this->content;
  }
}
$artCls = new Article('你好');
//编辑A先秀修改，然后编辑B修改，然后编辑C修改
$a = new editor_A($artCls);
$b = new editor_B($a);
$c = new editor_C($b);
echo $c->decorator();
//编辑B先秀修改，然后编辑A修改
$b = new editor_B($artCls);
$a = new editor_A($b);
echo $a->decorator();
//重点是传递参数的地方，使用Article $obj传递上一个操作的对象，
//来实现对同一个对象进行连续操作