I remember myself a tweet from Scott Hanselman a couple of months ago, where he asked us to check out a small application he wrote. As one of the first testers of his new "thing", I was interested but there were no documentation or libs available yet.
A couple of days a go, I read a blogpost from Maarten Balliauw about SignalR. . Because I allready heard about SignalR a couple of months ago, I had to develop a very small application to test how it really works.
1. Install SignalR package
You also have to update the jquery package to 1.6.2 or higher!(/images/jeroenb/signalr-starter-application/6f76bc2f-o_nuget.png)
2. Create a chat class
We only want 1 chat instance so use the Singleton pattern, lazy creation because that's thread safe.
public class Chat
{
private readonly static Lazy _instance = new Lazy( => new Chat);
public static Chat Instance
{
get
{
return _instance.Value;
}
}
}
3. Create a (chat)hub
Create a class ChatHub which will inherit from Hub
Have a look at the HubName attribute. That's the name you will use in javascript to define the connection.
[HubName("chatHub")]
public class ChatHub: Hub
{
private readonly int TimeoutInSeconds = 30;
private readonly Chat _chat;
public ChatHub: this(Chat.Instance) { }
public ChatHub(Chat chat)
{
_chat = chat;
}
}
4. Javascript connection
Create a connection between the client and the server. When the connection has been started, we want to call the join method on the server.
var chatHubClient = $.connection.chatHub;
// Start the connection
$.connection.hub.start(function {
chatHubClient.join('@Model.Name');
});
5. Model
Define a callback method on the server in the Chathub class
public void Join(string myName)
{
if (Chat.Clients.Where(x => x.Name.Equals(myName)).Count.Equals(0))
{
Chat.Clients.Add(new Client { Name = myName, LastResponse=DateTime.Now });
SendMessageServer(string.Format("{0} entered the chat", myName));
GetClients;
Caller.Naam = myName;
}
else
throw new Exception("This login is allready in use");
}
Download the Chat Application Example
Get more information on GitHub Listen to a podcast about SignalR on DotNetRocks