面向对象程序的设计模式-工厂模式

CommManager 类中的 getApptEncoder() 方法 专门用来负责生成相应的对象。

以下代码来自《深入PHP 面向对象、模式与实践》（第三版）第9章

<?php
/**
 * Created by PhpStorm.
 * User: Eilen
 * Date: 2018/9/2
 * Time: 8:40
 */

abstract class ApptEncoder
{
    abstract function encode();
}

class BloggsApptEncoder extends ApptEncoder
{
    public function encode()
    {
        return 'Appointment data encoded in BloggsCal format\n';
    }
}

class MegaApptEncoder extends ApptEncoder
{
    public function encode()
    {
        return 'Appointment data encoded in MegaCal format\n';
    }
}

class CommManager
{
    const BLOGGS = 1;
    const MEGA =2;
    private $mode;

    function __construct($mode)
    {
        $this->mode = $mode;
    }

    function getHeaderText()
    {
        switch ($this->mode){
            case (self::MEGA):
                return 'MegaCal header\n';
            default:
                return 'BloggsCal header\n';
        }
    }

    function getApptEncoder()
    {
        switch ($this->mode){
            case (self::MEGA):
                return new MegaApptEncoder();
            default:
                return new BloggsApptEncoder();
        }
    }
}

//引用工厂模式

$comm = new CommManager(CommManager::MEGA);
$mega = $comm->getApptEncoder();
echo $mega->encode();