How to reconnect websocket connection for OSC messages server in Node.js

Question

I have this server that receives osc messages and sends messages to other clients:

const osc = require('osc');
const WebSocket = require('ws');

const ws = new WebSocket('ws:192.xxx.x.xxx:8000');

var udp = new osc.UDPPort({
    localAddress: "0.0.0.0",
    localPort: 8000, 
});

udp.on('ready', function () {
    console.log('OSC Server is listening');
    console.log(JSON.stringify(udp));
});

// Receive osc message
udp.on('message', function (msg, timeTage, info) {
    console.log('An OSC message received: ', msg);

    // Send exact message to client a
    if(info.address !== '10.4.0.95') {
        udp.send(msg, '10.4.0.95', 9004);
    }

    // send message to other client
    if (msg.address.startsWith('/mov/moviePlayhead') && info.address !== '10.4.0.94') {
    udp.send(msg, '10.4.0.94', 9003)
    }

    else if (msg.address === '/bank/1/trig/3') {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'play', type: '3'}));
        }
    }
    else if (msg.address === '/bank/1/trig/2') {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'play', type: '5'}));
        }
    }
    else if (msg.address === '/bank/1/trig/1') {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'play', type: '7'}));
        }
    }
/*
    else {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'stop'}));
        }
    }
*/

});

udp.open();

On occasion, I get an error message 'Error: connect ECONNREFUSED 192.xxx.x.xxx:8000' that indicates that the connection was not made.

What can I add to the script so that it keeps reconnecting if the connection was dropped and I don't need to keep restarting the server when it does.

Any feedback on the script to make it better is also appreciated. Thank you!

Answer 1

I solved it by doing this:

const osc = require('osc');
const WebSocket = require('ws');

let ws = undefined;

function webSocket() {
    ws = new WebSocket('ws:192.xxx.x.xxx:8000');

    ws.on('open', function open() {
        console.log('WebSocket connected');
    });

    ws.on('close', function close() {
        console.log('WebSocket disconnected, attempting to reconnect...');
        setTimeout(webSocket, 1000);
    });

    ws.on('error', function error(err) {
        console.error('WebSocket encountered an error: ', err.message, 'Closing socket');
        ws.close();
    });
}

webSocket();

var udp = new osc.UDPPort({
    localAddress: "0.0.0.0",
    localPort: 8000, 
});

udp.on('ready', function () {
    console.log('OSC Server is listening');
    console.log(JSON.stringify(udp));
});

// Receive osc message
udp.on('message', function (msg, timeTage, info) {
    console.log('An OSC message received: ', msg);

    // Send exact message to client a
    if(info.address !== '10.4.0.95') {
        udp.send(msg, '10.4.0.95', 9004);
    }

    // Send message to tablet
    if (msg.address.startsWith('/mov/moviePlayhead') && info.address !== '10.4.0.94') {
    udp.send(msg, '10.4.0.94', 9003)
    }

    // Send message to other client
    if (msg.address === '/bank/1/trig/3') {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'play', type: '3'}));
        }
    }
    else if (msg.address === '/bank/1/trig/2') {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'play', type: '5'}));
        }
    }
    else if (msg.address === '/bank/1/trig/1') {
        if (ws.readyState === WebSocket.OPEN) {
            ws.send(JSON.stringify({event:'kaleidoscope', action: 'play', type: '7'}));
        }
    }

});

udp.open();