Publish to subscribed clients at scheduled times using reachphp or ratchet

Question

I'm new to reactphp. I dabbled in node.js. I'm researching a project that requires events to fire at specific times and get published to the subscribed clients. Is this something that the EventLoop would be suited for? Any direction for how I could approach this?

Answer 1

Your assumption of using the React EventLoop is correct. You can use a periodic timer to trigger sending messages. Since you mentioned Ratchet and published+subscribe I'm going to assume you're doing this using WAMP over WebSockets. Here's some sample code:

<?php
use Ratchet\ConnectionInterface;

class MyApp implements \Ratchet\Wamp\WampServerInterface {
    protected $subscribedTopics = array();

    public function onSubscribe(ConnectionInterface $conn, $topic) {
        // When a visitor subscribes to a topic link the Topic object in a  lookup array
        if (!array_key_exists($topic->getId(), $this->subscribedTopics)) {
            $this->subscribedTopics[$topic->getId()] = $topic;
        }
    }
    public function onUnSubscribe(ConnectionInterface $conn, $topic) {}
    public function onOpen(ConnectionInterface $conn) {}
    public function onClose(ConnectionInterface $conn) {}
    public function onCall(ConnectionInterface $conn, $id, $topic, array $params) {}
    public function onPublish(ConnectionInterface $conn, $topic, $event, array $exclude, array $eligible) {}
    public function onError(ConnectionInterface $conn, \Exception $e) {}

    public function doMyBroadcast($topic, $msg) {
        if (array_key_exists($topic, $this->subscribedTopics)) {
            $this->subscribedTopics[$topic]->broadcast($msg);
        }
    }
}

    $myApp = new MyApp;
    $loop = \React\EventLoop\Factory::create();
    $app = new \Ratchet\App('localhost', 8080, '127.0.0.1', $loop);
    $app->route('/my-endpoint', $myApp);

    // Every 5 seconds send "Hello subscribers!" to everyone subscribed to the "theTopicToSendTo" topic/channel
    $loop->addPeriodicTimer(5, function($timer) use ($myApp) {
        $myApp->doMyBroadcast('theTopicToSendTo', 'Hello subscribers!');
    });

    $app->run();