php装饰模式

/**
 * 抽象构件角色
 */
interface Component {
    /**
     * 示例方法
     */
    public function operation();
}
 
/**
 * 装饰角色
 */
abstract class Decorator implements Component{
 
    protected  $_component;
 
    public function __construct(Component $component) {
        $this->_component = $component;
    }
 
    public function operation() {
		//通过对象委派操作
        $this->_component->operation();
    }
}
 
/**
 * 具体装饰类A
 */
class ConcreteDecoratorA extends Decorator {
    public function __construct(Component $component) {
        parent::__construct($component);
 
    }
 
    public function operation() {
		
        parent::operation();    //  调用装饰类的操作
        $this->addedOperationA();   //  新增加的操作
    }
 
    /**
     * 新增加的操作A，即装饰上的功能
     */
    public function addedOperationA() {
        echo 'Add Operation A 
';
    }
}
 
/**
 * 具体装饰类B
 */
class ConcreteDecoratorB extends Decorator {
    public function __construct(Component $component) {
        parent::__construct($component);
 
    }
 
    public function operation() {
        parent::operation();//父类根据对象进行委派
        $this->addedOperationB();
    }
 
    /**
     * 新增加的操作B，即装饰上的功能
     */
    public function addedOperationB() {
        echo 'Add Operation B 
';
    }
}
 
/**
 * 具体构件
 */
class ConcreteComponent implements Component{
 
    public function operation() {
        echo 'Concrete Component operation 
';
    }
 
}
 
/**
 * 客户端
 */
class Client {
 
     /**
     * Main program.
     */
    public static function main() {
        $component = new ConcreteComponent();
        $decoratorA = new ConcreteDecoratorA($component);
        $decoratorB = new ConcreteDecoratorB($decoratorA);
 
        $decoratorA->operation();
        $decoratorB->operation();
    }
 
}
 
Client::main();
链接地址:http://www.phppan.com/2010/06/php-design-pattern-4-decorator/