Ratchet Websocket push integration - php

I am trying to develop a chat system using Websockets (Ratchet). Until now I have already made a functional PHP based Websocket server that is able to answer on predefined JSON encoded message using the following method.
function onMessage(ConnectionInterface $from, $msg){ ... }
The problem is that I'd like to push messages from the backend database via a background worker/thread to the right client, if something changed in my tables. Is this possible using PHP?
I don't want the client asking the websocket server every 5 minutes to refresh its state as shown below.
{"action":"giveMeUpdates"}
but the webserver should be able to do something like this:
{"status":"newMessages", "messagelist":[...]}
In addition:
class Chat extends ChatActionHandler implements MessageComponentInterface { ... }
this is my class where the ChatActionHandler holds functions for interacting with client requests. With the MessageComponentInterface i can only reply on Socket events like function onOpen(ConnectionInterface $conn). It is runned by the RatchetIO Server:
$server = IoServer::factory(
new Chat(),
8080);
$server->run();

You can attach timer, like cron with
$this->loop->addPeriodicTimer($timeout, function($timer) {});

Related

Ratchet + Symfony3: how to get access to current server from outside

Here is my Symfony3 command that I'm using for websocket server purpose
public function __construct(ChatFlowProcessor $chatManager, int $webSocketPort)
{
$this->chatManager = $chatManager;
$this->webSocketPort = $webSocketPort;
parent::__construct();
}
$server = IoServer::factory(
new HttpServer(
new WsServer(
$this->chatManager
)
),
$this->webSocketPort
);
$server->run();
As you see, I've got a chatManager simply using Symfony3 autowiring. The service implements Ratchet MessageComponentInterface.
Now, I want to get access to the server from outside of the connection. I mean, send a message to websocket client using my chatManager, apparently I need to get access to chatManager instance, that stored in WsServer and keep information about all active connections.
Is it possible? Thanks.
You dont need an access to chatManager just to send messages. It's a chat server which only purpose IS to transfer messages from/to all its clients.
Simply create a websocket client, connect it to your server (together other clients) and start sending (and receiving) messages. Any special functionality (e.g. send message to one client only or get list of all clients etc.) must be implemented in chatManager (Ratchets MessageComponentInterface).
Perhaps I misunderstood the question, sorry then.

Using reactive PHP in a blocking application

I'm currently working on a PHP application that will be using some websocket connections to talk to another service.
To talk to this websocket service, we are using Ratchet - which is a PHP library based on react PHP.
This piece of code needs to send and respond to a couple of requests, and after that, should return the information to the "main thread".
Example flow:
HTTP request -> controller -> Starts a service which opens a websocket client -> websocket client is talking to server -> once its done it should return the outcome to the controller code -> controller outputs to user
The issue I'm having is that I'm not familiar with Reactive PHP and am not sure how to handle this.
I've tried;
$service = new WebsocketService();
$startTimer = time();
$service->getList(44);
while($service->getResponse() == null) {
usleep(500);
if (time() > $startTimer + 10) {
continue; //Timeout on 10 seconds
}
}
var_dump($service->getResponse());
The service code would set its "response" variable to something other than null once its done. This obviously fails, because the sleep method is blocking the thread. Also without, it seems like the while loop is blocking I/O and the reactive code fails.
A solution would be to open up a new thread and run the websocket code there, but I wouldn't be happy with that.
I feel like I need to implement some sort of "watcher" around the websocket process, but I'm not sure how to do that.
Our Websocket service client code looks like this;
private $response = null;
/**
* #return null|object
*/
public function getResponse() {
return $this->response;
}
public function getList($accountId) {
$this->response = null;
\Ratchet\Client\connect('ws://192.168.56.1:8080')->then(function(\Ratchet\Client\WebSocket $conn) use ($accountId) {
$login = new \stdClass();
$login->action = 'login';
$conn->on('message', function($msg) use ($conn, $login, $accountId) {
try {
$response = json_decode($msg);
if ($response->result_id == 100) {
//Succesfully logged in to websocket server
//Do our request now.
$message = new \stdClass();
$message->target = 'test';
$conn->send(json_encode($message));
}
if (isset($response->reply) && $response->reply == 'list') {
$this->response = $response; //This is the content I need returned in the controller
$conn->close(); //Dont need it anymore
}
} catch (\Exception $e) {
echo 'response exception!';
//Do nothing for now
}
});
$conn->send(json_encode($login));
}, function ($e) {
echo "Could not connect: {$e->getMessage()}\n";
});
}
Running the code like this also does not work;
$service = new WebsocketService();
$service->getList(44);
echo 'Test';
var_dump($service->getResponse());
because the "test" echo comes before I even get a response from the websocket server.
Please, enlighten me! I'm not sure what to search for.
PHP and websockets still seem to be a bit experimental. Nevertheless I have found a great tutorial on medium.com, written by Adam Winnipass which should be really helpful for solving your problem: https://medium.com/#winni4eva/php-websockets-with-ratchet-5e76bacd7548
The only difference is that they are implementing their websocket client with JavaScript instead of PHP. But in the end there should not be much of a difference, because as soon as we have opened the Websocket connection of each end both applications have to send and also wait to receive notifications - this is how they illustrate it:
Seems like one possibility to create a successful Websocket connection is to extend the MessageComponentInterface
use Ratchet\MessageComponentInterface;
which also requires
use Ratchet\ConnectionInterface;
The message component interface defines the following methods:
onOpen
onMessage
onClose
onError
And I think this is how the Ratchet library is implementing it. This is how they are finally starting their server:
use Ratchet\Server\IoServer;
use MyApp\MyCustomMessageComponentInterface;
use Ratchet\Http\HttpServer;
use Ratchet\WebSocket\WsServer;
require dirname(__DIR__) . '/vendor/autoload.php';
$server = IoServer::factory(
new HttpServer(
new WsServer(
new MyCustomMessageComponentInterface()
)
),
8080
);
$server->run();
With this architecture you already can receive (onMessage) and sending is also possible with the send() method.
I can not solve the exact problem with your existing code. But I guess if you are using the pre-built classes and interfaces of the library as intended (and demonstrated here) you should be able to achieve what you want by adding your code to the corresponding methods.
More information and examples can be found in the docs:
http://socketo.me/docs/server
http://socketo.me/api/namespace-Ratchet.html
Are you extending class with WsServer, This might be issue, if you are getting fatal errors. I am not sure whether you are getting fatal errors or warnings. Also i notice the public function onOpen() opens a connection. Please try referring this document http://socketo.me/api/class-Ratchet.WebSocket.WsServer.html might be useful.

Websocket Testing [Functional]

I am using Ratchet for websockets in PHP. I was able to write unit (phpspec) and acceptance tests (behat) for websockets but I cannot find a way on how to test the connection to the websocket server by using a functional phpunit test.. I think a test, which checks if the connection is up and running, would be very important. I thought of something like the following:
Create a (ratchet) client in phpunit
Connect to ws url (e.g. client->connect(host, port, ...)
ping websocket / send / receive some messages (call methods of client, e.g. client->push(..)..)
The problem is, that I don't know which class is responsible for establishing the connection (creating a client which can request the websocket) in Ratchet and how a test would then look like. How can I create a Ratchet Client in order to be able to connect and request a websocket in phpunit functional test? (similar to e.g. a webclient within a standard phpunit functional test)
As an example, within a functional test for a feature, I could do the following:
$client = static::createClient();
$client->request('GET', '/book/3', array(), array(), array('HTTP_X-Requested-With' => 'XMLHttpRequest'));
$response = $client->getResponse();
$this->assertEquals(
440,
$response->getStatusCode()
);
Or e.g. create an authenticated client instead of an anonymous. How would it be possible, to "translate" this functional test into a ratchet websocket one?
I hope this partially solves your question of what part of the Ratchet Websocket is responsible of making a connection.
The test itself will probably not work, I am not that experienced with testing in PHP although it should put you on the right path.
public function testCanConnect()
{
\Ratchet\Client\connect('ws://127.0.0.1:8080')->then(function($conn) {
$conn->on('message', function($msg) use ($conn) {
print $msg."\n";
$this->assertEquals('true',true);
$this->assertEquals("Hello World",$msg);
$conn->close();
});
$conn->send('Hello World!');
}, function ($e) {
echo "Could not connect: {$e->getMessage()}\n";
});
}
If you have any further questions please let me know.

How to use Ratchet to respond to HTML5 server-side events?

(Note: I've intentionally put non adequate websocket tag here, as it's best chance for WebSocket expert folks to know architecture of Ratchet).
I'm up for implementing HTML5 server side events, and what I need is server side solution. Since hanging Apache's one process per connection (connection pool limit, memory consumption...) is out of consideration I was hoping that Ratchet project can be of help, since it's most maintained project and they have http server coupled along with other components.
My question is: how can I use it? Not for upgrading http request (default usage), but for serving dynamically generated content.
What have I tried so far?
installed Ratchet as explained in tutorial
tested WebSocket functionality - works properly
followed very basic set of instructions given on page that describes http server component:
/bin/http-server.php
use Ratchet\Http\HttpServer;
use Ratchet\Server\IoServer;
require dirname(__DIR__) . '/vendor/autoload.php';
$http = new HttpServer(new MyWebPage);
$server = IoServer::factory($http);
$server->run();
One should not be an expert to figure out that MyWebPage class here needs to be declared in order for server to work, but how?
The Ratchet documentation does not seems to cover this.
Your MyWebPage class needs to implement HttpServerInterface. Since it's just going to be a simple request/response you need to send a response and then close the connection within the onOpen() method of your class:
<?php
use Guzzle\Http\Message\RequestInterface;
use Guzzle\Http\Message\Response;
use Ratchet\ConnectionInterface;
use Ratchet\Http\HttpServerInterface;
class MyWebPage implements HttpServerInterface
{
protected $response;
public function onOpen(ConnectionInterface $conn, RequestInterface $request = null)
{
$this->response = new Response(200, [
'Content-Type' => 'text/html; charset=utf-8',
]);
$this->response->setBody('Hello World!');
$this->close($conn);
}
public function onClose(ConnectionInterface $conn)
{
}
public function onError(ConnectionInterface $conn, \Exception $e)
{
}
public function onMessage(ConnectionInterface $from, $msg)
{
}
protected function close(ConnectionInterface $conn)
{
$conn->send($this->response);
$conn->close();
}
}
I ended up using the Ratchet\App class instead of Ratchet\Http\HttpServer because it allows you to set up routing among other things, so your /bin/http-server.php would then look like this:
<?php
use Ratchet\App;
require dirname(__DIR__) . '/vendor/autoload.php';
$app = new App('localhost', 8080, '127.0.0.1');
$app->route('/', new MyWebPage(), ['*']);
$app->run();
When you run php bin/http-server.php and visit http://localhost:8080 you should see the Hello World! response in your browser.
This is all you need for a basic request/response system, but it could be extended further by implementing HTML templates and things like that. I've implemented this myself in a little test project which I've uploaded to github along with a lot of other things, including an abstract controller which I can extend for different pages.
Chat server using Ratchet - Basic
Chat server using Ratchet - Advanced
Check the link above. The guy here is using Ratchet to build a real time chat server. He is basically storing usernames initially and then sending/broadcasting to all. You can modify it and check at the time of sending that certain username or uid is active at the moment and send data to them only. You can generate data dynamically and send to particular users or to all. May be this will help.

Creating/Managing private rooms using Ratchet?

I am making iOS chat application. After doing study on needed technology and protocols, I decided to give a websockets try. For reasons our stack top is php based and I came to know about ratchet as websockets for PHP. I made simple chat server for ios front-end from reading documentation. Chat is working very fine and I am comfortable with it too. I wanted to know on how to create separate private chat rooms. Will different instance of socket event loop needed to run for separate rooms ?
The sample server I made is using single event loop for managing user connections and dispatching messages to different connection/user id's. I really tried to look out for creating private chat rooms but haven't found any information where I could be confident.
Will I have to manage each connection/user id's virtually on this event loop, like deciding which users can chat to each other directly by controlling the dispatching of messages ? Or is their really a separate way to do this ? This is the event loop sample as per documentation that I implemented:
<?php
use Ratchet\Server\IoServer;
use Ratchet\Http\HttpServer;
use Ratchet\WebSocket\WsServer;
use MyApp\Chat;
require dirname(__DIR__) . '/vendor/autoload.php';
$server = IoServer::factory(
new HttpServer(
new WsServer(
new Chat()
)
),
8080
);
$server->run();
I want to tell that I am a iOS/Android developer and really no expert or have fluent knowledge on web frontend/backend technologies.
Will different instance of socket event loop needed to run for separate rooms ?
No. Only one loop is needed. Your snippet is fine. What you have to do is to adjust Chat class so that it accepts additional parameter from the user input - room id/name.
For example, a user sends the message {"cmd":"msg", "message":"Hi", "room": 1}, then Chat should send the message only to the users who joined that room. And, of course, you should implement other user methods, such as {"cmd":"join", "room": 1}, {"cmd":"leave", "room": 1}
Well i might be a little bit late to answer, but here how i did that.
You should implement WampServerInterface instead of MessageComponentInterface on your Chat class (If you are not already doing so).
As said above your snippet is fine.
Here my Chat class :
class Chat implements WampServerInterface
{
protected $conversationId;
public function __construct(){
$this->conversationId = null;
}
public function onSubscribe(ConnectionInterface $conn, $conversation_id){
$this->conversationId = $conversation_id;
echo "Client $conn->resourceId assigned to the conversation : $conversation_id\n";
}
public function onPublish(ConnectionInterface $conn, $conversation_id, $event, array $exclude, array $eligible){
echo "Message sent to $conversation_id : $event";
// ... save in Database or else
// Send data to conversation
$this->conversationId->broadcast($message);
}
}
This is for a connection to one room only.
However if you want to have multiple chatrooms running in same time, you should have a look to Ratchet code on Github.
I don't know what did you use for the frontend, i personally use autobahn.js to instantiate the connection with the server (using ratchet).

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