PHP简单装饰器模式实现与用法示例

<?php//装饰器模式-在不改变原有类的结构上，对类的功能那个作补充//武器基类abstract class Weapon{  abstract public function descriptions();  abstract public function cost();}//剑类class Glave extends Weapon{  public function descriptions(){    return 'Glave';  }  public function cost(){    return "100";  }}//匕首类class Knife extends Weapon{  public function descriptions(){    return __CLASS__;  }  public function cost(){    return "80";  }}//斧类class Axe extends Weapon{  public function descriptions(){    return __CLASS__;  }  public function cost(){    return "200";  }}//属性类class Property extends Weapon{  protected $_weapon = null;  protected $_price = 0;  protected $_descriptions = '';  public function __construct(Weapon $weapon){    $this->_weapon = $weapon;  }  public function cost(){    return   $this->_weapon->cost() + $this->_price;  }  public function descriptions(){    return $this->_weapon->descriptions().$this->_descriptions;  }}//力量属性class Strength extends Property{  protected $_price = 30;  protected $_descriptions = '+ Strength';}//敏捷属性class Agility extends Property{  protected $_price = 50;  protected $_descriptions = '+ Agility';}//智力属性class Intellect extends Property{  protected $_price = 20;  protected $_descriptions = '+ Intellect';}$weapon = new Agility(new Strength(new Strength(new Glave())));echo $weapon->cost();echo $weapon->descriptions();