I have a signalR connection in a first page.
<script>
var online = $.connection.onlineHub;
online.client.aMessage = function () {
};
$.connection.hub.start().done(function () {
online.server.send();
});
</script>
The connection interrupt when i go to another page. Is there way this not happen.
There is no way to keep a SignalR connection open if your navigating away from the page responsible for initiating the connection.
One way you could potentially work around this issue is by creating a Single-Page Application or SPA.
Related
SignalR is running on a certain Server with an open connnection. If we need to bring up another server, then take the original down does SignalR automatically reconnect with the NEW server and start functioning like it was on the first?
We had a similar problem and what we discovered was that SignalR does not automatically reconnect with the new server. Our solution to was to not use the generated proxy. We used an intermediary endpoint whose job it is to provide the current url to use. To connect to SignalR our flow calls the endpoint gets the result using that result we connect to that server for SignalR then when the SignalR connection closes or is lost we repeat the process again as if for the first time.
async function reconnect(connection){
const signalRUrl = await request('<<our intermediary url>>');
connection.hub.url = signalRUrl;
connection.start();
}
var connection = $.hubConnection();
var hubProxy = connection.createHubProxy('yourHub');
hubProxy.on('message',function(){});
await reconnect(connection);
connection.onClose(function () {
reconnect(connection);
});
I use signalR to display currently connected users. Some clients are failing to see the connected clients because the server to client connection is being cancelled by the client as shown below:
Below is my js code:
var progressNotifier = $.connection.activeConnectionsHub;
$.connection.hub.start().done(function () {
progressNotifier.server.showActiveConnections();
// code here
});
// client-side sendMessage function that will be called from the server-side
progressNotifier.client.addConnections = function (param) {
// code here never gets called
}
This only happens on some client browsers.
I tried disabling antivirus, firewall, malware etc. But it is still not working.
Does anyone have an idea what is causing this issue?
I am using SignalR (with cross-domain request), version 2.3.0 for webchat integrated to ASP.NET site. Everything is working fine. But I found strange behaviour of SignalR connection. When I clicked to the reference from tab of the chat for file downloading SignalR connection was aborted and onDisconnected method was triggered in my Hub class. FireBug show me next POST-request:
http://*:81/signalr/abort?transport=longPolling&clientProtocol=1.4&token=eUpLNitKcmR1d2JhTTRvcHNVZmEwcG1EKzYvMElZbmg4aE5yam9xM3k0dz0_IjAsNGJmOWNhODUtNDU2NS00NWExLWFjMTgtNzgyN2FhZDA2Njg1LGxvY2FsaG9zdCI1&State=1&connectionToken=hDXe9xIZtmrapjl1LRwtK9B%2BfYMoeuHka8ctBLaPa0YnjiN9iiFa%2BvFMBHIGpGH0h8qPEDgGZSRGwjMw3Wm1DJi6cUPtZjLca6%2FR2576SGksLAj3lnPN1JWIlxMsn8%2Bf&connectionData=%5B%7B%22name%22%3A%22c%22%7D%2C%7B%22name%22%3A%22voip%22%7D%5D, where * is my domain.
It is reproduced in Mozilla Firefox (version 30.0) for LongPolling or Websocket transports. How I can fix this problem? Or is it bug of SignalR or Firefox?
This bug has been recently filed against SignalR on GitHub. The basic idea is that downloading a file causes Firefox to trigger the window.onbeforeunload event which in turn causes SignalR to close any ongoing connections.
For now, the workaround is to attach a handler to the client's disconnected event that will call $.connection.start again after a short window.setTimeout.
You could also unbind SignalR's onbeforeunload handler: $(window).unbind("beforeunload"). The downside of doing this is that Firefox might not gracefully disconnect when the user leaves the page running SignalR. Without a graceful disconnect, SignalR will wait over 30 seconds before it times out the client and calls the OnDisconnected handler on the Hub or PersistentConnection.
I have managed to use the workaraound explained by halter73 and I have solved the issue described by dudeNumber4 resetting the connectionid inside the disconnect event so that the server kept calling back the right users based on their connectionid without the need to address them by their user or group names.
$.connection.hub.disconnected(function () {
setTimeout(function () {
$.connection.hub.start().done(function () {
$("#mySignalRConnectionIdHidden").val($.connection.hub.id);
});
}, 3000);
});
I am building a single page app which uses sammy.js, knockout.js and SignalR. The main page (index.html) loads additional html pages into a div based upon the client side route.
I have 2 SignalR hubs, one is connected to by the initial page for server side push data and this works fine. However one of the pages which are loaded when the user navigates to it should also connect to a different hub.
In the main page I am doing the following:
window.hubReady = $.connection.hub.start()
var hub1 = $.connection.hub1;
hub1.updateReceived = function () {
alert('data from server');
}
window.hubReady.done(function() {
hub1.server.start();
});
In the second page I have:
var hub2 = $.connection.hub2;
hub2.updateReceived = function () {
alert('data from server');
}
window.hubReady.done(function() {
hub2.server.start();
});
However I never receive any updates in the second page.
Any idea where I am going wrong?
In order to receive updates from a hub you must have at least 1 client side function declared for that hub when the connection is started. Judging from the libraries you are using I'm assuming you have a single page application and therefore don't instantiate your hub2 data until the connection has already started.
So an easy fix would be to just declare a hub2 client side function alongside your hub1 client side function before start is called. If you want to add more client side functions after the connection has started you'll have to use the .on method.
AKA:
hub2.on("updateReceived", function () {
alert("data from server");
});
I have created a lib called SignalR.EventAggregatorProxy.
it proxies between server side domain events and client side code. Its designed with MVVM and SPA in mind and takes care of all the hub plumbing. Check the wiki for how to set it up.
https://github.com/AndersMalmgren/SignalR.EventAggregatorProxy/wiki
once its configured all you need to subscribe to a event is
ViewModel = function() {
signalR.eventAggregator.subscribe(MyApp.Events.TestEvent, this.onTestEvent, this);
};
MyApp.Events.TestEvent corresponds to a server side .NET event. You can also constraint which event should go to which usera
I have some doubts regarding my software design with signalr,
usually I start with this code:
var connection = $.hubConnection();
var notifier = connection.createHubProxy('notifier');
connection.start()
.done(function () {
//alert('connection was succesful');
// your event handlers
});
UPDATED QUESTION
If you have a common click event handler that will only use signalR to broadcast a message, and this event handler is on a separate javascript file (out of the context of the current connection):
should I open the connection in the external script? or
should I send a reference of the proxy (already connected) to the external script?
When your page doesn't need a connection you should not open one.