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();