netsocket

Small library to easily deal with websockets using .NET Standard 2.0.

How can I consume this?

PM> Install-Package Valudio.NetSocket

How does it work?

This library comes with a middleware that you can use in your Startup.cs file:

public void ConfigureServices(IServiceCollection services)
{
    services.AddRealTimeComm(); // this will inject all the services
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    loggerFactory.AddConsole();
    app.UseRealTimeComm(); // this will start listening (Note that you can pass the ports your application will be listening here)
    if (env.IsDevelopment()) app.UseDeveloperExceptionPage();
}

Once you have set this up the next step is to create your own classes extending SocketServiceBase . You will have 4 methods to override:

// this will be executed whenever a new websocket is open.
public virtual void OnClientInitialized(IClient client) { }
// this will be executed whenever the server receives some message.
public virtual void OnMessageReceived(IClient fromClient, string message) { }
// this will be executed whenever the server sents any message to some client
public virtual void OnMessageSent(IClient toClient, string message, IClient fromClient) { }
// this will be executed whenever a websocket is closed.
public virtual void OnClientClosed(IClient client) { }

Besides those virtual methods you've got some other methods that will be useful to send messages:

// just like the method's name says... sends a message to everyone.
Task SendAllClientsAsync(string message, IClient fromClient = null);
// sends a message to all the clients except the one you pass as a parameter.
Task SendAllClientsExceptAsync(IClient except, string message, IClient fromClient = null);
// sends a message to all the clients except the ones you pass as a parameter.
Task SendAllClientsExceptAsync(IEnumerable<IClient> except, string message, IClient fromClient = null);
// sends a message to a specific client.
Task SendClientAsync(IClient toClient, string message, IClient fromClient = null);

Enabling / Disabling SocketServices

Let's say you want to not use one of your SocketServices (your classes extending SocketServiceBase). You've got the option to mark them with an attribute SocketServiceAttribute:

// setting this attribute to false will make this service not to be used by the middleware.
// this attribute is only necessary to deactivate the service. If not present
[SocketService(false)]
public class HelloTimerService : SocketServiceBase
{
    public HelloTimerService(ISocketManager manager) : base(manager)
    {
        var timer = new System.Threading.Timer(async (o) =>
        {
            await SendAllClientsAsync($"Hello at {DateTime.Now.ToUniversalTime()}");
        }, null, 0, 30000);
        
    }
}

Sending additional parameters to the server

If you want to send additional custom data through the socket connection you can add it to the url as a query string

var url = "ws://domain.com/ws?param1=value&param2=value";
var socket = new WebSocket(url);

You will receive that data in the property AdditionalParameters as a Dictionary<string, StringValues> in the IClient passed as a parameter to the virtual methods of your SocketServices

How to test this

Run one of the example projects and then use Simple Web Socket Client for Chrome, for instance, in order to setup a websocket connection.

Alternatively, if you don't want to run the examples, you can use this url ws://examplenetsocketnetcore.azurewebsites.net. The website also has a simple form to test it

Bear in mind this is a F1 free Azure Machine so it will have to start-up first. Stay calm if first request takes longer than it should. ;D