provm/events

Event handler for WebSocket

1.0.0 2021-03-30 20:41 UTC

Requires

• cboden/ratchet: ^0.4.3
• psr/event-dispatcher: ^1.0

Requires (Dev)

• kint-php/kint: ^3.3
• phpunit/phpunit: ^9.5

MIT

• Aldarien

README

WebSockets app for PHP. Using Ratchet as a base for creating the app it can be used as framework for connecting to the database from the web UI.

Introduction

I wrote this project because I had a hard time finding any alternative to handling Server-Side WebSocket with PHP. Ratchet handles the connection but not the app itself. I needed an app structure similar to Slim which was what I work with. This is the result.

Installation

Use composer.

composer require aldarien/events

Use

I recommend you setup your app with a Container like PHP-DI

Base example:

$app = ProVM\Common\Alias\Server\App::factory(
  new Ratchet\Server\HttpServer(
    new Ratchet\Server\WsServer(
      new ProVM\Common\Alias\Event\Message(new SplObjectStorage())
    )
  ),
  $port ?? 8010
);
$app->add('event_name', function($request, $response) {
  // do action
  return $response;
})
$app->run();

Breakdown:

The app is created similar to Ratchet with the wrapper ProVM\Common\Alias\Server\App but the message handler is from this package ProVM\Common\Alias\Event\Message which handles all event dispatches and listeners.

Then the event(s) are added with $app->add it requires a name for the event and a callable handler that work similar to Slim Controllers.

Finally just $app->run

You can use a Listener for the callable:

class Handler {
  public function __invoke($request, $response) {
    // do something else
    return $response;
  }
  public function other($request, $response) {
    // other action
    return $response;
  }
}
$app->add('event2', new Handler());
$app->add('other', [new Handler(), 'other']);

In the web UI just create a websocket:

var conn = new WebSocket(websocket_url)
conn.onopen = function(e) {
  // open event
}
conn.onmessage = function(e) {
  // listen to messages received
}
conn.onerror = function(e) {
  console.error(e)
}
conn.onclose = function(e) {
  // check if e.code == 1000 closed without error)
}
msg = {
  action: 'event_name',
  data: []
}
conn.send(JSON.stringify(msg))

Breakdown:

Create the websocket connection new WebSocket(websocket_url) where websocket_url can be something like ws://localhost:8010 or wss://localhost:8010 where the port is the same one set in the app.

Set the event listeners for open, message, error and close and start sending messages with send

Take note of the last lines where the message received by the app needs an action equivalent to the event names added before and the data associated if any (can be missing).