How to determine server disconnection from SignalR client?

Question

How can a SignalR JavaScript client detect when a connection with the server is lost?

Do you use signalr with asp.net? – Sinan AKYAZICI Feb 02 '12 at 10:45 — Sinan AKYAZICI, Feb 02 '12 at 10:45

score 33 · Answer 1 · edited Apr 22 '13 at 07:38

33

A hub has a method disconnect which will allow you to add a callback when disconnection takes place:

myHub.disconnect(function() {
  alert('Server has disconnected');
});

If you aren't using hubs then the code for the disconnect method will help you out:

$(connection).bind("onDisconnect", function (e, data) {
  callback.call(connection);
});

This shows the syntax for hooking onto the onDisconnect event of the underlying connection.

edited Apr 22 '13 at 07:38

MrBilde

43
6

answered Feb 03 '12 at 00:48

John Rayner

3,485
21
13

3

Don't use bind... just do connection.disconnected – davidfowl Jun 15 '12 at 09:20
1

The proper method for this is now `$.connection.hub.disconnected(callback)` – Jeremy Boyd Dec 07 '17 at 18:33

score 13 · Answer 2 · answered Feb 02 '12 at 23:02

If you are using hubs then implement the IDisconnect interface.

public class ChatHub : Hub, IDisconnect
{
    public void Disconnect()
    {
        Debug.WriteLine(Context.ConnectionId + " disconnected");
    }
}

On persistent connections you can override OnDisconnectAsync, (from the SignalR wiki at https://github.com/SignalR/SignalR/wiki/PersistentConnection )

public class MyEndPoint : PersistentConnection 
{
    protected override Task OnDisconnectAsync(string clientId) 
    {
        return Connection.Broadcast("Client " + clientId + " disconncted");   
    }
}

This is actually very useful as an answer unrelated to the question, thank you! — Josh, Jul 24 '14 at 01:56

score 8 · Answer 3 · answered Jul 30 '14 at 16:14

8

The SignalR 2.0 way of doing this is like so:

$.connection.hub.disconnected(function () {
    console.log('Connection disconnected')
});

http://www.asp.net/signalr/overview/signalr-20/hubs-api/hubs-api-guide-javascript-client#connectionlifetime

answered Jul 30 '14 at 16:14

gholmes

101
1
7

score 8 · Answer 4 · answered Oct 03 '18 at 07:15

This worked for me using "@aspnet/signalr": "^1.0.0" npm package

const connection = new signalr.HubConnectionBuilder()
    .withUrl('url')
    .configureLogging(signalr.LogLevel.Information)
    .build()

connection.onclose(() => {
   // close logic goes here
})

score 6 · Answer 5 · answered Oct 20 '12 at 11:14

Starting with SignalR v0.5.1 it works this way:

$.connection.hub.stateChanged(function (change) {
    if (change.newState === $.signalR.connectionState.reconnecting) {
        console.log("liveFeed is reconnecting!");
    }
    else if (change.newState === $.signalR.connectionState.connected) {
        console.log("liveFeed is connected!");
    }
});

For more details check this website:

http://weblogs.asp.net/davidfowler/archive/2012/06/10/signalr-0-5-1-released.aspx

score 3 · Answer 6 · answered Jan 30 '15 at 09:58

3

The below, worked for me:

var connection = $.hubConnection('signalrConnectionUrl');

connection.disconnected(function() {
    console.log('Connection disconnected');
});

I'm using version: 2.1.2

See the following link for reference: Link

answered Jan 30 '15 at 09:58

martinmose

443
8
12

score 1 · Accepted Answer · answered Apr 04 '22 at 14:41

1

The provided answers will no longer work. This is the new way to stop/disconnect connections.

myHub.stop().then(() => {
  alert('Server has disconnected');
});

answered Apr 04 '22 at 14:41

Alireza

2,319
2
23
35

How to determine server disconnection from SignalR client?

7 Answers7

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