设计模式之Command

 

<?php
interface ICommand
{
    function onCommand($name, $args);
}

class CommandChain
{
    private $_commands = array();

    public function addCommand($cmd)
    {
        $this->_commands[] = $cmd;
    }

    public function runCommand($name, $args)
    {
        foreach ($this->_commands as $cmd) {
            if ($cmd->onCommand($name, $args)) {
                return;
            }
        }
    }
}

class UserCommand implements ICommand
{
    public function onCommand($name, $args)
    {
        if ($name != 'addUser') {
            return false;
        }

        echo "Run UserCommand <br />";
        return true;
    }
}

class MailCommand implements ICommand
{
    public function onCommand($name, $args)
    {
        if ($name != 'mail') {
            return false;
        }

        echo "Run MailCommand <br />";
    }
}

$cc = new CommandChain();
$cc->addCommand(new UserCommand());
$cc->addCommand(new MailCommand());
$cc->runCommand('addUser', null);
$cc->runCommand('mail', null);

 

 输出结果

Run UserCommand
Run MailCommand