php设计模式之命令链模式

1. 使用场景
1. 命令连模式可以使用在用户登陆注册的时候处理不同角色用户的业务逻辑,与变量值
<?php
/**

 * command interface

 *

*/

interface MyCommand

{

    public function onCommand( $name, $args );

}



//user register

class Register

{

    private $_commandsChain = array();



    public function addCommand( $cmd )

    {

        $this->_commandsChain []= $cmd;

    }



    public function runCommand( $name, $args )

    {

        foreach( $this->_commandsChain as $cmd )

        {

            if ($cmd->onCommand( $name, $args )) {

                return;

            }

        }

    }

}



//common logic

class CommonCommand implements MyCommand

{

    public function onCommand( $name, $args )

    {

        if ($name != 'common_user' ) {

            return false;

        }

        echo "I am common member\n";

        return true;

    }

}



//vip logic

class VipCommand implements MyCommand

{

    public function onCommand( $name, $args )

    {

        if ($name != 'vip_user') {

            return false;

        }

        echo "I am vip member\n";

        return true;

    }

}



//实例化注册器

$cc = new Register();

//运行普通用户的处理逻辑

$cc->addCommand( new CommonCommand() );

//运行高级用户的处理逻辑

$cc->addCommand( new VipCommand() );

//运行普通用户的处理逻辑

$cc->runCommand( 'common_user', null );

//运行高级用户的处理逻辑

$cc->runCommand( 'vip_user', null );