PHP结构型模式之装饰器模式

<?php
// 抽象组件
interface Component
{
    public function operation();
}
// 具体组件
class ConcreteComponent implements Component
{
    public function operation()
    {
        echo "ConcreteComponent operation.\n";
    }
}
// 抽象装饰器
abstract class Decorator implements Component
{
    protected $component;
    public function __construct(Component $component)
    {
        $this->component = $component;
    }
    public function operation()
    {
        $this->component->operation();
    }
}
// 具体装饰器A
class ConcreteDecoratorA extends Decorator
{
    public function operation()
    {
        parent::operation();
        $this->addedBehavior();
        echo "ConcreteDecoratorA operation.\n";
    }
    public function addedBehavior()
    {
        echo "Added behavior in ConcreteDecoratorA.\n";
    }
}
// 具体装饰器B
class ConcreteDecoratorB extends Decorator
{
    public function operation()
    {
        parent::operation();
        $this->addedBehavior();
        echo "ConcreteDecoratorB operation.\n";
    }
    public function addedBehavior()
    {
        echo "Added behavior in ConcreteDecoratorB.\n";
    }
}
// 客户端代码
$component = new ConcreteComponent();
$decoratorA = new ConcreteDecoratorA($component);
$decoratorB = new ConcreteDecoratorB($decoratorA);
$decoratorB->operation();

<?php
$component = new ConcreteComponent();
$decoratorA = new ConcreteDecoratorA($component);
$decoratorB = new ConcreteDecoratorB($decoratorA);
$decoratorB->operation();