PHP 装饰器模式

装饰器模式简介

1. 装饰器模式（Decorator），可以动态地添加修改类的功能
2. 一个类提供了一项功能，如果要在修改并添加额外的功能，传统的编程模式，需要写一个子类继承它，并重新实现类的方法
3. 使用装饰器模式，仅需在运行时添加一个装饰器对象即可实现，可以实现最大的灵活性

示例代码

<?php/** * 输出一个字符串 * 装饰器动态添加功能 * Class EchoText */class EchoText{ ???protected $decorator = []; ???public function Index() ???{ ???????//调用装饰器前置操作 ???????$this->beforeEcho(); ???????echo "你好，我是装饰器。"; ???????//调用装饰器后置操作 ???????$this->afterEcho(); ???} ???//增加装饰器 ???public function addDecorator(Decorator $decorator) ???{ ???????$this->decorator[] = $decorator; ???} ???//执行装饰器前置操作 先进先出原则 ???protected function beforeEcho() ???{ ???????foreach ($this->decorator as $decorator) ???????????$decorator->before(); ???} ???//执行装饰器后置操作 先进后出原则 ???protected function afterEcho() ???{ ???????$tmp = array_reverse($this->decorator); ???????foreach ($tmp as $decorator) ???????????$decorator->after(); ???}}/** * 装饰器接口 * Class Decorator */interface Decorator{ ???public function before(); ???public function after();}/** * 颜色装饰器实现 * Class ColorDecorator */class ColorDecorator implements Decorator{ ???protected $color; ???public function __construct($color) ???{ ???????$this->color = $color; ???} ???public function before() ???{ ???????echo "<dis style='color: {$this->color}'>"; ???} ???public function after() ???{ ???????echo "</div>"; ???}}/** * 字体大小装饰器实现 * Class SizeDecorator */class SizeDecorator implements Decorator{ ???protected $size; ???public function __construct($size) ???{ ???????$this->size = $size; ???} ???public function before() ???{ ???????echo "<dis style='font-size: {$this->size}px'>"; ???} ???public function after() ???{ ???????echo "</div>"; ???}}//实例化输出类$echo = new EchoText();//增加装饰器$echo->addDecorator(new ColorDecorator('red'));//增加装饰器$echo->addDecorator(new SizeDecorator('22'));//输出$echo->Index();

PHP 装饰器模式

原文地址：https://www.cnblogs.com/jjxhp/p/10061688.html