How to reconnect when a WebSocket disconnects?

Question

Example:

var WebSocket = require('ws');
var ws = new WebSocket('ws://echo.websocket.org/', {protocolVersion: 8, origin: 'http://websocket.org'});
ws.on('open', function() {
    console.log('connected');
    ws.send(Date.now().toString(), {mask: true});
});
ws.on('close', function() {
    console.log('disconnected');
    // What do I do here to reconnect?
});

What should I do when the socket closes to reconnect to the server?

If I remember correctly sockets try to reconnect upon disconnection — Sterling Archer, Jul 30 '14 at 21:38
A robust solution isn't too terrible but it's not exactly a 5 line patch either. Here's one solution. https://github.com/joewalnes/reconnecting-websocket/blob/master/reconnecting-websocket.js#L124 — aembke, Jul 30 '14 at 23:01
@aembke: joewalnes' project has been [abandoned](https://github.com/joewalnes/reconnecting-websocket/issues) for over a year and it's unclear if it targets node or the browser. — Dan Dascalescu, Jan 11 '18 at 23:57
Duplicate of [NodeJS Websocket how to reconnect when server restarts](https://stackoverflow.com/questions/19691996/nodejs-websocket-how-to-reconnect-when-server-restarts) — Dan Dascalescu, Jan 11 '18 at 23:58

score 1 · Answer 1 · answered Jul 31 '14 at 03:24

You can wrap all your setup in a function and then call it from the close handler:

var WebSocket = require('ws');
var openWebSocket = function() {
    var ws = new WebSocket('ws://echo.websocket.org/', {protocolVersion: 8, origin: 'http://websocket.org'});
    ws.on('open', function() {
        console.log('connected');
        ws.send(Date.now().toString(), {mask: true});
    });
    ws.on('close', function() {
        console.log('disconnected');
        openWebSocket();
    });
}
openWebSocket();

However, there is likely more logic you want here (what if the close was on purpose? what happens if you try to send a message while its reconnecting?). You're probably better off using a library. This library suggested by aembke in the comments seems reasonable. socket.io is not a bad choice (and it gives you non-WebSocket transports).

How to reconnect when a WebSocket disconnects?

1 Answers1

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