TCP Socket with Javascript

How-to Discussions
1

Hi all,
I’m new to fuse and I’m looking to create a TCP connection within Javascript.

I saw Uno.Net.Sockets but not sure it can be called with Javascript !

There is sample somewhere about how to use Uno.Net.Sockets ?

Thank you for your help.

2

We have not exposed this api to JavaScript yet. You can still use this from Uno and expose it your self to JS.

3

Here my MySocket.uno code

using Fuse;
using Fuse.Scripting;
using Fuse.Reactive;
using Uno.UX;
using Uno.Net.Sockets;
using Uno.Text;
using Uno.Threading;


[UXGlobalModule]
public class MySocket : NativeModule
{
    static readonly MySocket _instance;
    
    NativeEvent _nativeEvent;
    NativeEvent _nativeEventConnected;
    NativeEvent _nativeEventError;
    Socket socket;

    public MySocket()
    {
        // Make sure we're only initializing the module once
        if(_instance != null) return;
        _instance = this;
        Resource.SetGlobalKey(_instance, "MySocket");
        AddMember(new NativeFunction("connect", (NativeCallback)Connect));
        AddMember(new NativeFunction("send", (NativeCallback)Send));
        AddMember(new NativeFunction("read", (NativeCallback)Read));
        
        _nativeEvent = new NativeEvent("onMessageReceived");
        AddMember(_nativeEvent);
        _nativeEventConnected = new NativeEvent("onConnected");
        AddMember(_nativeEventConnected);
        _nativeEventError = new NativeEvent("onError");
        AddMember(_nativeEventError);

    }

    string Send(Context c, object[] args)
    {
        var message = args[0] as string;
        var connected = socket.Connected;
        debug_log(connected);
        socket.Send(Ascii.GetBytes(message));
        debug_log(message);
        _nativeEvent.RaiseAsync("SENT");
        return "";
    }

    string Connect(Context c, object[] args)
    {
        socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);       
        var address = args[0] as string;
        debug_log address;
        int port = int.Parse(args[1] as string);
        debug_log port;
        debug_log socket;
        try {
          socket.Connect(address, port);
          _nativeEventConnected.RaiseAsync("Connected");
          
        } catch(SocketException e) {
          _nativeEventError.RaiseAsync(e.Message);
        }
        return "";
    }

    string Read(Context c, object[] args)
    {
        var read = new byte[] {};
        socket.Receive(read);
        debug_log("Read data : " + Ascii.GetString(read));
        _nativeEvent.RaiseAsync(Ascii.GetString(read));
        return "";
    }
    

    
}

The Connect method is working fine, the Send method too … but my Read method return nothing (always blank)

Here the view :

<App>
    <DockPanel>
        <StatusBarBackground Dock="Top" />
        <ScrollView ClipToBounds="true">
            <StackPanel>
                <Text FontSize="30" Alignment="Center">Hello, world!</Text>
                <Button Text="Send DETECT" Clicked="{onClick}"/>
                <Button Text="Read Buffer" Clicked="{onClickRead}"/>
        
                
                
            </StackPanel>
        </ScrollView>
        <JavaScript>
          var Socket = require('MySocket');
          var Observable = require('FuseJS/Observable');
          var buttonText = Observable('Button');
          
          Socket.connect("127.0.0.1", "8888");
          
          Socket.onError = function(message) {
            console.log(message);
          }
          Socket.onConnected = function(message) {
            console.log(message);
          }
          Socket.onMessageReceived = function(message) {
            console.log(message);
            if(message == "SENT") {
              Socket.read();
            }
          }
          
          function onClick() {
             Socket.send("DETECT\n");
          }

          function onClickRead() {
             Socket.read();
          }

          module.exports = {
              buttonText: buttonText,
              onClick: onClick,
              onClickRead: onClickRead,
          }
      </JavaScript>
    </DockPanel>
</App>

The server is a nodeJS TCP server which works fine (tested with a ruby client)

Any thought about my .uno file ? How to run a loop to catch any new data in the Socket ? I’m a newbie on C#

4

Hi!

Our socket API is based on the C# socket API. My suggestion is to have a look at the C# documentation and examples for sockets https://msdn.microsoft.com/en-us/library/w89fhyex(v=vs.110).aspx

5

Well, I can’t see the BeginReceive method … I don’t see where to set the callback method for reads.

Looks like it differ a bit from the C# version …:frowning:

6

Ok I have found how to read data … Now I need to find how to run the read inside a Thread … Do you have any Thread code sample within UNO ?

7

Threading in Uno is very similar to C# 2.0 even though we don’t have all the high level methods (like BeginReceive), it should be possible to read up on the general documentation.

8

I did write a simple project which works fine now … I hope it will help beginners

Any thoughts will be welcome :slight_smile: