I have an API controller that creates a web socket connection and can connect and interact with fine when using JavaScript, but I'd also like to be able to connect to it using a C# client. I've tried a few different libraries (Alchemy, WebSocket4Net, and WebSocket-Sharp), and they all seem to be timing out during connection open.
Here's the code for the server side:
class WsController : ApiController
{
public HttpResponseMessage Get(string id)
{
HttpContext.Current.AcceptWebSocketRequest(new WsHandler(id));
return Request.CreateResponse(HttpStatusCode.SwitchingProtocols);
}
internal class WsHandler : WebSocketHandler
{
public WsHandler(string id) { /* ... */ }
}
}
If I'm using a JS client, I can use var ws = new WebSocket(url + "?id=someid"); to connect and then send and receive messages. When using a C# client, I get stuck during the handshake and the connect times out. Here's some example code using WebSocket4Net.
var ws = new WebSocket(url);
ws.Opened += new EventHandler(ws_Connect);
ws.Closed += new EventHandler(ws_Disconnect);
ws.Error += new EventHandler<ErrorEventArgs>(ws_Error);
ws.MessageReceived += new EventHandler<MessageReceivedEventArgs>(ws_Receive);
ws.Open(); // Timeout on this line. No errors are thrown to ws_Error.
Is there another way to create a websocket server using MVC's ApiController?
Related
I am building a simple restaurant management system in WPF. I have my backend in Laravel. I needed to setup a web socket to get real-time notifications on WPF app when a customer places an order from mobile app. I configured the web socket in Laravel using beyondcode/laravel-websockets. For ease, I tested the web socket on client side using laravel-echo with Vue. Everything works well there but I couldn't find any solution to replicate laravel-echo in C#.
Here is the code I am using in Vue.js with laravel-echo:
import Echo from "laravel-echo";
import Pusher from "pusher-js";
window.Pusher = Pusher;
const token = "1|CSaob3KZhU5UHiocBjPgzpazbceUKTLRLJO0ZIV0"
window.Echo = new Echo({
broadcaster: 'pusher',
key: 'laravel_rdb',
wsHost: '127.0.0.1',
authEndpoint: 'http://localhost/may-app/public/broadcasting/auth',
encrypted: false,
forceTLS: false,
wsPort: 6001,
wssPort: 6001,
disableStats: true,
enabledTransports: ['ws', 'wss'],
auth : {
headers : {
Authorization: "Bearer " + token,
Accept: "application/json",
}
},
})
window.Echo.private('customer-order')
.listen('OrderPlaced', (e) => {
console.log(e)
})
I found SocketIOClient is used to implement web socket functionality in .NET. I tried to use a solution I found here but it didn't work for me. Also, I didn't find any way to set up my authentication URL in this package. I read socket.io documentation for anything related to authentication but I couldn't find any.
How do I implement equivalent functionality in C# .NET as in laravel-echo?
There is probably no client like laravel-echo for .NET. However, you will be able to connect to your sockets using pusher client: pusher/pusher-websocket-dotnet and this is probably the highest level of compatibility you can reach. But you will need to parse your messages and subscribe to the channels by yourself, there will be no sweet wrapping like in laravel-echo =(
I was able to implement a solution using the package mentioned by PunyFlash in the answers. The NuGet package is available here and here is the GitHub repo.
My solution might be useful for someone in the future so, my equivalent code for the laravel-echo code above, in .NET is:
internal class OrderSocket
{
public static async void Connect()
{
try
{
//Setting authentication
var authorizer = new CustomAuthorizer("http://localhost/may-app/public/broadcasting/auth")
{
AuthenticationHeader = new System.Net.Http.Headers.AuthenticationHeaderValue("Authorization", "Bearer " + "1|CSaob3KZhU5UHiocBjPgzpazbceUKTLRLJO0ZIV0"),
};
//Creating pusher object with authentication
Pusher pusher = new Pusher("laravel_rdb", new PusherOptions
{
Authorizer = authorizer,
Host = "127.0.0.1:6001",
});
//Connecting to web socket
await pusher.ConnectAsync().ConfigureAwait(false);
//Subscribing to channel
Channel channel = await pusher.SubscribeAsync("private-customer-order").ConfigureAwait(false);
if (channel.IsSubscribed)
{
//Binding to an event
channel.Bind("App\\Events\\OrderPlaced", (PusherEvent eventResponse) =>
{
// Deserialize json if server returns json values
Debug.WriteLine(eventResponse.Data);
});
}
}
catch (Exception)
{
Debug.WriteLine("An exception occurred.");
}
}
}
//HttpAuthorizer child class to set default headers
internal class CustomAuthorizer : HttpAuthorizer
{
public CustomAuthorizer(string authEndpoint) : base(authEndpoint) { }
public override void PreAuthorize(HttpClient httpClient)
{
base.PreAuthorize(httpClient);
httpClient.DefaultRequestHeaders.Add("Accept", "application/json");
}
}
I have a WebSite integrated with SignalR. It functions well, and it has a button which sends popup notification to all clients who are online. It works well when I click on the button.
My API is in another project but in the same Solution. I want to send the above notification by calling from the API side. Basically, a mobile app will send a request to API and then API will send a notification to all online web clients.
Below code runs and not gives the notification nor any error.
Is this fundamentally correct? Appreciate your help
API code (at WebAPI project)
[HttpGet]
public IEnumerable<string> WatchMe(int record_id)
{
GMapChatHub sendmsg = new GMapChatHub();
sendmsg.sendHelpMessage(record_id.ToString());
return "Done";
}
C# code (at Web project)
namespace GMapChat
{
public class GMapChatHub : Hub
{
public void sendHelpMessage(string token)
{
var context = GlobalHost.ConnectionManager.GetHubContext<GMapChatHub>();
context.Clients.All.helpMessageReceived(token, "Test help message");
}
}
}
Home.aspx file (at Web project)
var chat = $.connection.gMapChatHub;
$(document).ready(function () {
chat.client.helpMessageReceived = function (token,msg) {
console.log("helpMessageReceived: " + msg);
$('#helpMessageBody').html(msg)
$('#helpModal').modal('toggle');
};
}
You can not call that hub directly. Firs you need to install the .net client for SignalR from nuget. Then you need to initialize it like this :
[HttpGet]
public IEnumerable<string> WatchMe(int record_id)
{
using (var hubConnection = new HubConnection("your local host address"))
{
IHubProxy proxy= hubConnection.CreateHubProxy("GMapChatHub");
await hubConnection.Start();
proxy.Invoke("sendHelpMessage",record_id.ToString()); // invoke server method
}
// return sth. IEnumerable<string>
}
And opening a new connection per request may not be good idea you may make it per session (if you use) or static or time fashioned.
I have written an Application where I am using SignalR. I am sending connectionId from Client to Server(controller).
Everything is working fine with single browser (request will sent to server with connectionId="conn_1") and signalR is sending response to only conn_1, but when i open new browser and send a request from that client the previous connection gets disposed. Which means only one connection with particular connectionId remains alive.
Is there any way SignalR can not dispose and send response to both with data they want?
I am new to SignalR and would really appropriate any help or guidance.
Angular SignalRService to start connection with server
this.hubConnection = new signalR.HubConnectionBuilder()
.withUrl(this.paymentDraftHubUrl)
.build();
return this.hubConnection
.start()
.then(() => this.hubConnectionStatus = 'Connection started')
.catch(err => (this.hubConnectionStatus = 'Error while starting connection: ' + err));
}
sending connectionId from client component to Api
this.signalRService.startConnection().then((connection) => {
this.connectionId = connection.toString();
//Calling Api
this.getAllTransactionException(
this.connectionId,
this.pageNumber,
this.pageSize
}
MyHub class in C#
public class PaymentDraftServiceHub : Hub, IPaymentDraftHub
{}
Controller for API
using timer to keep calling repository for new data,
[HttpGet]
[Route("GetCsrTranactions")]
public IActionResult GetCsrTranactions([FromQuery] TransactionExceptionDataRequest queryParams)
{
TimeManager.Dispose();
var timerManager = new TimeManager(async () =>
await _paymentDraftHub.Clients.Clients.Client(queryParams.ConnectionId).SendAsync(SignalRConstants.TransferPaymentDraftServiceData, await _paymentTransactionRepository.GetCsrTranactionsAsync(queryParams)));
var response = new ResponseMessage { Message = "Accepted", Code = "201" };
return Ok(response);
}
Client can have multiple connections with multiple connection IDs if client connect from multiple browser windows or tabs.
According to the code you provided, we can find that you just pass connection ID of SignalR client within current active browser tab/window to your controller, and in your controller action, you use this code snippet .Client(queryParams.ConnectionId).SendAsync() to send message to a specific client, so other browser windows or tabs would not receive the message.
If you'd like to send message(s) to a client with multiple connections, you need to map SignalR users to connection Ids and retain information about users-to-connectionIds mapping, then you can get all connectionIds of a client and send messages to that client with with multiple connectionIds, like below.
//code logic here
//to get all connectinIds of a client/user
//from user-to-connectionIds mapping table
await _paymentDraftHub.Clients.Clients(connectionIds_here).SendAsync("method_here",args_here);
I have an P2P network app which acts as a server and client.
The app connects to multiple clients in a mesh and sends "data" to each other once the data has been processed.
If a client gets an incoming request then creates their own request before completing the incoming request it seems to deadlock and neither requests complete. Everything works fine unless a create is sent which processing one.
Is this because I'm not using async on the server methods or is this because I shouldn't send a request while processing one?
proto
rpc submit_data(DataSubmission) returns (DataSubmissionAck);
RPC Server
public async void Start()
{
_server = new Server()
{
Services = {
DataService.BindService(new DataService())),
},
Ports = { new ServerPort(_IpAddress, _Port, ServerCredentials.Insecure) }
};
_server.Start();
}
Client method
public void SubmitData(Data data)
{
...
var serverResponse = _serviceClient.submit_data(request);
...
}
Server method
public override Task<DataSubmissionAck> submit_data(DataSubmission request, ServerCallContext context)
{
DataSubmissionAck clientResponse = new DataSubmissionAck();
return Task.FromResult(clientResponse);
}
What seems to have worked is making the server and client-side calls all async.
I was using Alchemy websockets for both my client and server but ran into a problem with corrupted/dropped messsages. So I'm trying out another server side implementation. I implemented the server using Fleck, and when I send messages using javascript, the server receives all the messages, solving my previous problem.
However, I need to be able to send messages to the websocket server from a C# client also. Since Fleck does not have a client side implementation in C#, I thought I'd stick with Alchemy. I left the client-side code unchanged so I thought it should just connect to the server as before, however, no messages are being received (though they are being sent according to the debugger).
Here is my server side implementation (Fleck):
private void OnStartWebSocketServer()
{
var server = new WebSocketServer("ws://localhost:11005");
server.Start(socket =>
{
socket.OnOpen = () => Console.WriteLine("Open!");
socket.OnClose = () => Console.WriteLine("Close!");
socket.OnMessage = message => OnReceive(message);
});
}
private static void OnReceive(String message)
{
UpdateUserLocation(message);
}
Here is my client side implementation (Alchemy):
class WSclient
{
WebSocketClient aClient;
public WSclient(String host, String port)
{
aClient = new WebSocketClient("ws://" + host + ":" + 11005 + "/chat")
{
OnReceive = OnReceive,
OnSend = OnSend,
OnConnect = OnConnected,
OnConnected = OnConnect,
OnDisconnect = OnDisconnect
};
aClient.Connect();
}
...
public void Send(String data)
{
aClient.Send(data);
}
I thought it might have something to do with the fact that the Alchemy client requires a channel at the end of the connection string '/chat'. However leaving it blank, or just the '/' gives an error.