mrboh / WebSharper.SignalR

WebSharper bindings for SignalR

WebSharper.SignalR

WebSharper bindings for SignalR

To use:

1. Add NuGet package: weatherwax.io.WebSharper.SignalR
2. Add services.AddSignalR() and app.UseSignalR(..) to the Startup class of a Sitelet project. Using a SiteletService allows you to easily make use of the IHubContext<'THub>.

member this.ConfigureServices(services: IServiceCollection) =
        // Hook in SignalR
        services.AddSignalR () |> ignore
        ...
        
member this.Configure(app: IApplicationBuilder, env: IHostingEnvironment) =
    // Configure SignalR
    app.UseSignalR(
        fun hubRouteBuilder ->
            hubRouteBuilder.MapHub<SampleHub> (PathString "/signalr")
    ) |> ignore
    ...

3. Create Hub

type SampleHub () =
    inherit Hub ()

    member _this.ServerMessage (message: string) : Task =
        Task.Run (
            fun _ ->
                // Send the message back to the client
                _this.Clients.Caller.SendAsync ("ClientMessage", sprintf "The following message was sent to the server and re-sent back to the client: %s" message)
        )

4. Create connection object on the client

[<JavaScript>]
module Client =
    let private connection = HubConnectionBuilder().WithUrl("/signalr").ConfigureLogging(LogLevel.Trace).Build()

    let private configureSignalR element =
        let handleMessage =
            Action<_>(
                fun (message: string) ->
                    ...
            )

        // Monitor for messages
        connection.On ("ClientMessage", handleMessage)

        // Commence signal monitoring
        connection
            .Start()
            .Catch(fun err -> JavaScript.Console.Error <| err.ToString ())
            |> ignore
            
    let Main () =
        div [ on.afterRender configureSignalR ] [
          ...

To see a basic working example, look at the sample project.

Issues

Likely many, has not been tested to a great extent. The biggest issue I am aware of is that, the way the API/bindings are structured, complex structures do not seem to translate across from client to server and vice versa. I'm not sure if this is a WebSharper issue, a SignalR issue or just the bindings being implemented poorly. My workaround has been to serialize the objects with WebSharper, send the string via SignalR, then deserialize on the receiving end, which has worked well.