PHP学习：学习php设计模式 php实现装饰器模式(decorator)

PHP教程
<?php
/**
 * 抽象构件角色
 */
interface Component {
 /**
  * 示例办法
  */
 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() {
  $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 <br />';
 }
}
 
/**
 * 具体装饰类B
 */
class ConcreteDecoratorB extends Decorator {
 public function __construct(Component $component) {
  parent::__construct($component);
 
 }
 
 public function operation() {
  parent::operation();
  $this->addedOperationB();
 }
 
 /**
  * 新增加的操作B,即装饰上的功能
  */
 public function addedOperationB() {
  echo 'Add Operation B <br />';
 }
}
 
/**
 * 具体构件
 */
class ConcreteComponent implements Component{
 
 public function operation() {
  echo 'Concrete Component operation <br />';
 }
 
}
 
/**
 * 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();
?>