Can't invoke client functions from the Server - asp.net-mvc

Question

I'm working on a small concept trying to get to work with SignalR.
In this scenario all connected clients need to refresh when one of the clients perform an update, this update is performed through an Ajax request.
Because there might be different instances of the page, depending on a parameter, I'm using groups for this.
The client side code looks as followed:
<script>
window.onload = function () {
DoRefresh();
}
$(function () {
var hub = $.connection.commonHub;
hub.client.refresh = function () {
DoRefresh();//This doesn't get called for the other clients
};
$.connection.hub.start();
$.connection.hub.start().done(function () {
hub.server.join("MyPage" + #Model.Id + "");
});
});
function htmlEncode(value) {
var encodedValue = $('<div />').text(value).html();
return encodedValue;
}
function DoRefresh() {
$.ajax({
url: '#Url.Action("LoadData")',
cache: false,
data: "&id=" + #Model.Id + "",
success: function (html) {
$("#conversation").empty();
$("#conversation").append(html);
},
error: function (xhr, status, err) {
alert('Response code:' + xhr.status + '\r\n[Error:' + err + '] ' + status);
}
});
return false;
};
function DoUpdate() {
$.ajax({
url: '#Url.Action("DoUpdate")',
cache: false,
data: "&id=" + #Model.Id + "&posterID=" + #userAccount.AccountID + "&message=" + $("#Textbox").val().replaceAll("\n", "[br]"),
success: function () {
$("#Textbox").empty();
DoRefresh();
},
error: function () {
$("#Textbox").empty();
DoRefresh();
}
});
return false;
};
</script>
In my controller, following functions are part of this scenario:
public class MyController : Controller
{
private Hubs.CommonHub hub = new Hubs.CommonHub();
//Some other Controller Methods
public PartialViewResult LoadData(int id)
{
MyModel item = Connection.DB.MyData.FirstOrDefault(x => x.Id == id);
return PartialView(item);
}
public virtual EmptyResult DoUpdate(int id, int posterID, string message)
{
message = message.Replace("[br]", "\r\n");
MyModel item = Connection.DB.MyData.FirstOrDefault(x => x.Id == id);
Account poster = Connection.DB.Accounts.FirstOrDefault(x => x.Id == posterID);;
item.Updates.Add(new Update()
{
PosterId = posterID,
Poster = poster,
Id = id,
Item = item,
PostDate = DateTime.UtcNow,
Message = message.Replace(Environment.NewLine,"\r\n")
});
Connection.DB.SaveChanges();
hub.Refresh("MyPage" + item.Id);
return null;
}
}
And finally, my hub class looks like this:
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Threading.Tasks;
using System.Web;
using Microsoft.AspNet.SignalR;
using MyProject.Models;
namespace MyProject.Hubs
{
public class CommonHub : Hub
{
private string myInfo;
public override Task OnConnected()
{
myInfo = Context.ConnectionId;
return base.OnConnected();
}
public Task Join(string groupName)
{
return Groups.Add(Context.ConnectionId, groupName);
}
public Task Leave(string groupName)
{
return Groups.Remove(Context.ConnectionId, groupName);
}
public void Refresh(string groupName)
{
var context = GlobalHost.ConnectionManager.GetHubContext<CommonHub>();
context.Clients.Group(groupName).Refresh();
}
}
}
The Join task in the hub is called with every connect of a new browser window. The Refresh method is invoked on the hub, but only the invoking window has its page refreshed. The client side refresh function only gets invoked once when debugging, probably for the invoking client.
I have no idea why the other clients are not doing their updates, please help.