How to send messages to particular users Ratchet PHP Websocket

Question

I\'m trying to build a system where user can subscribe to a category on establishing connection to websocket server and then he will start receiving updates for that category. S

Answer 1

Basically you want a syntax for sending data to the WebSocket, I reccomend using a JSON object to do this. In your WebSocket class you need a local variable called subscriptions and a local variable called users like so.

clients = new \SplObjectStorage;
        $this->subscriptions = [];
        $this->users = [];
    }

    public function onOpen(ConnectionInterface $conn)
    {
        $this->clients->attach($conn);
        $this->users[$conn->resourceId] = $conn;
    }

    public function onMessage(ConnectionInterface $conn, $msg)
    {
        $data = json_decode($msg);
        switch ($data->command) {
            case "subscribe":
                $this->subscriptions[$conn->resourceId] = $data->channel;
                break;
            case "message":
                if (isset($this->subscriptions[$conn->resourceId])) {
                    $target = $this->subscriptions[$conn->resourceId];
                    foreach ($this->subscriptions as $id=>$channel) {
                        if ($channel == $target && $id != $conn->resourceId) {
                            $this->users[$id]->send($data->message);
                        }
                    }
                }
        }
    }

    public function onClose(ConnectionInterface $conn)
    {
        $this->clients->detach($conn);
        unset($this->users[$conn->resourceId]);
        unset($this->subscriptions[$conn->resourceId]);
    }

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

The javascript to go with that looks a bit like this

Note: This code is untested I wrote it on the fly from my experience with Ratchet. Good luck :)