Introduction to ReactPHP and Websockets

ReactPHP (& Ratchet)

The solution in PHP

ReactPHP

ReactPHP is an event driven, non-blocking I/O framework for webservice in PHP

(think NodeJS on the server, but with PHP)

Runs on a separate port on the server, needs to be proxied through the webserver

Handles thousands of connections and events in a single PHP process

Does not need any special extensions in PHP, but leverages new features in PHP 8.1 like fibers

Ratchet

A websocket implementation with ReactPHP

Basic Implementation (server side)

						composer require cboden/ratchet
					

						use Ratchet\MessageComponentInterface;
						use Ratchet\ConnectionInterface;

						require_once __DIR__ . "/vendor/autoload.php";

						$app = new Ratchet\App('0.0.0.0', 8080);
						$app->route('/echo', new Ratchet\Server\EchoServer, array('*'));
						$app->run();
					

Client Side

							var conn = new WebSocket('ws://0.0.0.0:8080/echo');
							conn.onopen = function(ev) {
								conn.send('hello');
							}
							conn.onmessage = function(ev) {
								let li=document.createElement('li');
								li.innerText = ev.data;
								document.getElementById('log').append(li);
							}
						

Distributing the message

Chat server side

class MyChat implements MessageComponentInterface {
	protected $clients;
	public function __construct() {
		$this->clients = new \SplObjectStorage;
	}
	public function onOpen(ConnectionInterface $conn) {
		$this->clients->attach($conn);
	}
	public function onMessage(ConnectionInterface $from, $msg) {
		foreach ($this->clients as $client) {
			$client->send($msg);
		}
	}
	public function onClose(ConnectionInterface $conn) {
		$this->clients->detach($conn);
	}
	public function onError(ConnectionInterface $conn, \Exception $e) {
		$conn->close();
	}
}
					

$app = new Ratchet\App('0.0.0.0', 8080);
$app->route('/chat', new MyChat, array('*'));
$app->run();