设计模式(9)decorator模式

abstract class Component{
  public abstract function operation();
}
class ConcreteComponent extends Component{
  public function operation(){
    echo "我是被装饰的类的方式!!!";
  }
}

abstract class Decorator extends Component{
  protected $component;
}
class ConcreteDecoratorA extends Decorator{
  private $decoratorA;
  function __construct(Component $component){
    $this->component = $component;
  } 
  public function operation(){
    $this->component->operation();
    //add varaiable
    $this->decoratorA = 11;
    echo "我增加了一个变量，值是11";
  }

}
class ConcreteDecoratorB extends Decorator{
  function __construct(Component $component){
    $this->component = $component;
  } 
  public function operation(){
    $this->component->operation();
    //add function
    $this->decoratorFun();
  }
  public function decoratorFun(){
    echo "新增一个方法";
  }

}
//测试代码
$concreteComponent = new ConcreteComponent();
$concreteDecoratorA = new ConcreteDecoratorA($concreteComponent);
$concreteDecoratorB = new ConcreteDecoratorB($concreteComponent);
//增加变量
$concreteDecoratorA->operation();
$concreteDecoratorB->operation();
//在A的基础上增加B
$concreteDecoratorC = new ConcreteDecoratorB($concreteDecoratorA);
$concreteDecoratorC->operation();