适用性
对现有的对象增加功能
和适配器的区别：适配器是连接两个接口，装饰器是对现有的对象包装
代码示例
/**
* 鞋接口
*/
interface ShoesInterface
{
public function product();
}
/**
* 装饰器抽象类.
*/
abstract class Decorator implements ShoesInterface
{
/**
* 产品生产线对象
*/
protected $shoes;
/**
* 构造函数.
*/
public function __construct(ShoesInterface $shoes)
{
$this->shoes = $shoes;
}
/**
* 生产.
*/
public function product()
{
$this->shoes->product();
}
/**
* 装饰操作.
*/
abstract public function decorate($value);
}
/**
* 贴标装饰器
*/
class DecoratorBrand extends Decorator
{
private $_brand;
/**
* 构造函数
*/
public function __construct(ShoesInterface $phone)
{
$this->phone = $phone;
}
public function __set($name='', $value='')
{
$this->$name = $value;
}
/**
* 生产
*/
public function product()
{
$this->phone->product();
$this->decorate($this->_brand);
}
/**
* 贴标操作
*/
public function decorate($value='')
{
echo "贴上{$value}标志 \n";
}
}
/**
* 滑板鞋实体
*/
class ShoesSkateboard implements ShoesInterface
{
public function product()
{
echo "生产一滑板鞋";
}
}
/**
* 运动鞋实体
*/
class ShoesSport implements ShoesInterface
{
public function product()
{
echo "生产一双球鞋";
}
}
try {
echo "未加装饰器之前：\n";
// 生产运动鞋
$shoesSport = new ShoesSport();
$shoesSport->product();
echo "\n--------------------\n";
echo "加贴标装饰器：\n";
// 初始化一个贴商标适配器
$DecoratorBrand = new DecoratorBrand(new ShoesSport());
$DecoratorBrand->_brand = 'nike';
// 生产nike牌运动鞋
$DecoratorBrand->product();
} catch (\Exception $e) {
echo $e->getMessage();
}
