Reference socket.io instance in another file with multiple exports (node.js)

Question

I am probably missing something, but I cannot get my head around on how to properly reference a socket (created with socket.io) in another file. I have a server.js file:

const app = express();
const io = require('socket.io')(server, {
  cors: {
    origin: 'http://localhost:8081',
    methods: ['GET', 'POST'],
    allowedHeaders: ['my-custom-header'],
    credentials: true,
  },
});
require('./controllers/buildXLS.js')(io);

I want to access io in another file ('./controllers/buildXLS.js'):

module.exports = io => {
  io.on('connection', client => {
    client.on('subscribeToProgress', () => {
      console.log('client is subscribing to progress');
    });
  });
};

Now this works fine with module.exports, but a exports.io = io =>... crashes the server (require is not a function). I do have several other exports in buildXLS.js, which will be destroyed by module.exports. Is there any way around that? I need io in buildXLS.js, as it will emit progress updates. Thanks

Aryan · Accepted Answer · 2020-11-12 17:49:30Z

1

In below code I have exported io object from app.js and you can easily use it where you want

const server = require('http').createServer(app);
const io = require('socket.io')(server, {
  cors: {
    origin: 'http://localhost:8081',
    methods: ['GET', 'POST'],
    allowedHeaders: ['my-custom-header'],
    credentials: true,
  },
});

io.on('connection', async (socket) => {
    console.log('socket connected', userId)

    if (io.nsps['/'].adapter.rooms["room-" + userId] && io.nsps['/'].adapter.rooms["room-" + userId].length > 0) userId++;
    socket.join("room-" + userId);
    io.sockets.in("room-" + userId).emit('connectToRoom', "You are in room no. " + userId);
});

const socketIoObject = io;
module.exports.ioObject = socketIoObject;

where you want to get that function use below code

const socket = require('../app');//import object

socket.ioObject.sockets.in("_room" + room_id).emit("hello", "how are you");

answered Nov 12, 2020 at 17:49

Aryan

3,6465 gold badges23 silver badges49 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

x-feed Over a year ago

Thank you, this works! I simplified it a bit (I am doing a fairly simple project without the need to differentiate namespaces and rooms).

Collectives™ on Stack Overflow

Reference socket.io instance in another file with multiple exports (node.js)

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related