PHP设计模式之装饰者模式，代码练习

<?php
/**
* 装饰者模式
*/

/**
 * 冰激凌抽象类
 */
abstract class ICE
{
    public abstract function getDescription();
    public abstract function cost();
}

/**
 * 牛奶冰激凌，售价17RMB
 */
class MilkIce extends ICE
{
    public $description = '纯牛奶制作的冰激凌';

    public function getDescription()
    {
        return $this->description;
    }

    public function cost()
    {
        return 17;
    }
}

/**
 * 沙冰冰激凌，售价10RMB
 */
class SlushIce extends ICE
{
    public $description = '冰块制作的冰激凌';

    public function getDescription()
    {
        return $this->description;
    }

    public function cost()
    {
        return 10;
    }
}

/**
 * 冰激凌调料抽象类
 */
abstract class CondimentIce extends ICE
{
    //public abstract function getDescription();
    //public abstract function cost();
}

/**
 * 加香菜口味，附加5RMB
 */
class Herb extends CondimentIce
{
    public $ice;
    public $description;

    public function __construct($ice)
    {
        $this->ice = $ice;
        $this->description = '法国香草';
    }

    public function getDescription()
    {
        return $this->ice->getDescription() . ',' . $this->description;
    }

    public function cost()
    {
        return $this->ice->cost() + 5;
    }
}

/**
 * 加草莓口味，附加8RMB
 */
class Berries extends CondimentIce
{
    public $ice;
    public $description;

    public function __construct($ice)
    {
        $this->ice = $ice;
        $this->description = '野草莓';
    }

    public function getDescription()
    {
        return $this->ice->getDescription() . ',' . $this->description;
    }

    public function cost()
    {
        return $this->ice->cost() + 8;
    }
}


// example
// 购买一个奶油香草冰激凌
$ice_object = new MilkIce();
$ice_object = new Herb($ice_object);
echo $ice_object->cost();
echo $ice_object->getDescription();

// 购买一个沙冰+香草+草莓
$ice2 = new SlushIce();
$ice2 = new Herb($ice2);
$ice2 = new Berries($ice2);
echo $ice2->cost();
echo $ice2->getDescription();

是不是有些像递归调用