Design Patterns PHP Ed - Command Mode

Benpian example by dining at a restaurant, you need to go a la carte restaurant, waiter record when ordering, the waiter record to complete the list of chefs, cooks cooking.

/**
 * Interface Command 命令角色
 */
interface Command
{
    /**
     * @return mixed 执行方法
     */
    public function execute();
}

/**
 * Class ConcreteCommand 具体命令类，执行具体的行为：厨师
 */
class ConcreteCommand implements Command
{
    /**
     * @var Receiver 用于存放Receiver类
     */
    private $_receiver;

    public function __construct(Receiver $receiver)
    {
        $this->_receiver = $receiver;
    }

    public function execute()
    {
        // 厨师一顿操作后，终于完成了
        $complete = true;

        if ($complete == true) {
            $card = '食屎啦你'; // 厨师为了你给他带来了今天大汗淋漓的工作，为了表示感谢，送出了一张卡片
            $this->_receiver->action($this->_receiver->_name, $card); // 菜做好了，通知服务员上菜
        } else {
            echo '滚你丫的别BB，我还没想出来怎么做';
        }
    }
}

/**
 * Class Receiver 接收者角色：服务员
 */
class Receiver
{
    /**
     * @var string 服务员记录了菜名
     */
    public $_name;

    public function __construct($name)
    {
        $this->_name = $name;
    }

    public function action($name = null, $card = null) // 这个方法是厨师那边调用的
    {
        echo '服务员上菜: ' . $name;
        if (!empty($card)) {
            echo "<br>$card";
        }
    }
}

/**
 * Class Invoker 请求者角色：点餐的客人，你
 */
class Invoker
{
    /**
     * @var Command 存放ConcreteCommand类
     */
    private $_command;

    public function __construct(Command $command)
    {
        $this->_command = $command;
    }
    public function action()
    {
        $this->_command->execute();
    }
}

$receiver = new Receiver('满汉全席'); // 你点了满汉全席，服务员（Receiver类）记录了菜名。
$command = new ConcreteCommand($receiver); // 你看着服务员拿着单子进了厨房，空着手出来，厨师拿到了单子。
$invoker = new Invoker($command); // 你确定厨房已有你这个单子了。
$invoker->action(); // 因为你之前还有朋友没到，朋友到了后你跟服务员说可以做菜了。

Scenario:
The person with a command executor completely decoupled.
Visible, you are in full interaction with the waiter, who cooks do not have to pipe Yes.

Internet search a lot of information, I did not find this mode dim, or am I not understanding?

Eight down, I feel it is easy to understand, but to write out the role, really hard. The key is that few people see. . Therefore, the design patterns more stops. .