periodically sending messages to all clients using signalr - asp.net

Question

I want to send some data from server to all connected clients using hubs after a specific interval. How can I accomplish this using signalr hubs.

Answer 1

Spin up the System.Threading.Timer, and from it's callback broadcast the message using specific hub.
Global.asax:
private Timer timer;
public class Global : System.Web.HttpApplication
{
protected void Application_Start(object sender, EventArgs e)
{
RouteTable.Routes.MapHubs("~/signalr2");
timer = new Timer(TimerCallback(timerCallback), null, Timeout.Infinite, 1000);
}
}
Check the “Broadcasting over a Hub from outside of a Hub” section in SignalR wiki page.

Answer 2

Use ReactiveExtensions and then setup an Observable.Interval call. Then reactive will automatically call the lambda which can broadcast to your clients.

Answer 3

I have stumbled upon this post by Jason Roberts => http://dontcodetired.com/blog/post/Using-Server-Side-Timers-and-SignalR-in-ASPNET-MVC-Applications.aspx
He uses IRegisteredObject and HostingEnvironment.RegisterObject then a System.Threading.Timer in the class that does the work, I haven't tried it myself, but it looks exactly the sort of thing.

Answer 4

Just add
Thread.Sleep(5000);
in your send Method.
Ex:
public void Send(string name, string message)
{
Thread.Sleep(5000);
//call the broadcast message to upadate the clients.
Clients.All.broadcastMessage(name, message);
}
Hope it helps.
Edit
The following code renders the current time for every 5 seconds.
Here is script for it:
<script type="text/javascript">
$(function () {
$.connection.hub.logging = true;
$.connection.hub.start();
// Declare a proxy to reference the hub.
var chat = $.connection.chatHub;
//Appending the responce from the server to the discussion id
chat.client.currentTime = function (time) {
$('#discussion').append("<br/>" + time + "<br/>");
};
// Start the connection.
$.connection.hub.start().done(function () {
//Call the server side method for every 5 seconds
setInterval(function () {
var date = new Date();
chat.client.currentTime(date.toString());
}, 5000);
});
});
</script>
<div id="discussion"></div>
And on the HubClass write the following:
public class ChatHub: Hub
{
public void currentTime(string date)
{
Clients.All.broadCastTime(date);
}
}