SignalR JavaScript client connect

Question

I'm new to SignalR and I really don't have a clue. I need to connect to a stream and retrieve some data. I have gotten some help from the owner, but they don't know how to create it with JavaScript.

They gave me the following C# code:

private static HubConnection _hubConnection;
private static IHubProxy _hubProxy;

_hubConnection = new HubConnection("https://sesignalr.esmartapi.com/realtime");
_hubProxy = _hubConnection.CreateHubProxy("timeseriesHub");
_hubProxy.On<ValueResult>("broadCastValue", RecieveServerStreamMessageObject);

_hubConnection.Start().Wait();

_hubProxy.Invoke("Subscribe", assetId).Wait();


private static void RecieveServerStreamMessageObject(ValueResult message)
{
    Console.WriteLine(message.ValueTime.ToShortDateString() + " " + message.ValueTime.ToLongTimeString() + " - Value: " + message.Value + " (id " + message.AssetId + ")");
}

public class ValueResult
{
    public string AssetId { get; set; }
    public int ValueCategory { get; set; }
    public DateTime ValueTime { get; set; }
    public Double Value { get; set; }
    public int ValueUnit { get; set; }
}

So I tried the connection using the following JavaScript code:

var connection = $.hubConnection('https://sesignalr.esmartapi.com/realtime');
var proxy = connection.createHubProxy('timeseriesHub');

// receives broadcast messages from a hub function, called "broadcastMessage"
proxy.on('broadcastMessage', function(message) {
    console.log(message);
});

// attempt connection, and handle errors
connection.start({ jsonp: true })
.done(function(){ console.log('Now connected, connection ID=' + connection.id); })
.fail(function(){ console.log('Could not connect'); });

And running this gave the following error:

403 (Forbidden: JSONP is disabled.)

I think I'm supposed to recreate the C# code above with JavaScript, but my C# knowledge is limited and I have no experience with this. I'm not sure how to do this, any help is appreciated.

Answer 1

I don't think you can really connect to a stream using javascript, its more of a notification framework. You need to notify the javascript client that something has changed, and update either through making another server call, or from data in the notification you send.

That C# code is horrible by the way, Its trying to create a synchronous stream out of an async notification framework. Signalr is not going to work well this way. IMO.