Php 创建websocket聊天室

我有一个可以工作的Ratchet聊天套接字服务器，但是每个连接的人都可以与每个人聊天。如何在代码中实现聊天室，我希望用户能够在服务器上连接的每个人都看不到的聊天室中聊天

ChatServer.php

<?php

require_once 'vendor/autoload.php';

use Ratchet\Server\IoServer;
use Ratchet\MessageComponentInterface;
use Ratchet\ConnectionInterface;
use Ratchet\Http\HttpServer;
use Ratchet\WebSocket\WsServer;


echo "Hello";

class Chat implements MessageComponentInterface {

    protected $clients;

    public function __construct() {
        $this->clients = new \SplObjectStorage;
    }

    public function onOpen(ConnectionInterface $conn) {
        // Store the new connection to send messages to later
        $this->clients->attach($conn);

        echo "New connection! ({$conn->resourceId})\n";
    }

    public function onMessage(ConnectionInterface $from, $msg) {
        $numRecv = count($this->clients) - 1;
        echo sprintf('Connection %d sending message "%s" to %d other connection%s' . "\n"
            , $from->resourceId, $msg, $numRecv, $numRecv == 1 ? '' : 's');

        foreach ($this->clients as $client) {
            if ($from !== $client) {
                // The sender is not the receiver, send to each client connected
                $client->send($msg);
                echo $msg;
            }
        }
    }

    public function onClose(ConnectionInterface $conn) {
        // The connection is closed, remove it, as we can no longer send it messages
        $this->clients->detach($conn);

        echo "Connection {$conn->resourceId} has disconnected\n";
    }

    public function onError(ConnectionInterface $conn, \Exception $e) {
        echo "An error has occurred: {$e->getMessage()}\n";

        $conn->close();
    }
}

$server = IoServer::factory(
    new HttpServer(
        new WsServer(
            new Chat()
        )
    ),
    8080
);


$server->run();