【php设计模式】装饰器模式

<?php

/**
*装饰器模式
**/

interface Component{
    public function operation();
}

class ConcreteComponent implements Component{
    public $put_str = "具体实现类";
    
    public function operation(){
        echo $this->put_str."\n";
    }

    public function addElement($str){
        $this->put_str = $str.$this->put_str;
    }
}

abstract class Decorator implements Component{
    public $comm;
    public function __construct(Component $comm){
        $this->comm = $comm;
    }
    abstract function operation();
}

class ConcreteDecoratorA extends Decorator{
    public function operation(){
        $this->comm->addElement("被A修饰后的");
        $this->comm->operation();
    }
}

class ConcreteDecoratorB extends Decorator{
    public function operation(){
        $this->comm->addElement("被B修饰后的");
        $this->comm->operation();
    }
}

$comm = new ConcreteComponent();
$comm->operation();    // 输出 “具体实现类”
$decorate_a = new ConcreteDecoratorA($comm);
$decorate_a->operation();  // 输出 “被A修饰后的具体实现类”
$decorate_b = new ConcreteDecoratorB($comm);
$decorate_b->operation();  // 输出 “被B修饰后的被A修饰后的具体实现类”