socket.io 2.0 get connected clients in a room

Question

How can you retrieve all the connected clients in a room using socket.io 2.0

I already tried the solution in a similar question: https://stackoverflow.com/a/45160538/2189845

var sockets = io.in("room_name")
 Object.keys(sockets.sockets).forEach((item) => {
 console.log("TODO: Item:", sockets.sockets[item].id)            
})

But this loops over all socket connections, regardless of the room. So the code above gives the same result as:

Object.keys(io.sockets.sockets).forEach((item) => {
    console.log("general socket: Item:", item);
});

score 2 · Accepted Answer · answered Aug 02 '17 at 17:46

2

Unfortunately, this answer doesn't completely satisfy OPs question. If you are using socket.io-redis to manage socket connections you can get connected clients like

io.of('/').adapter.clients((err, clients) => {
  console.log(clients); // an array containing all connected socket ids
});

io.of('/').adapter.clients(['room1', 'room2'], (err, clients) => {
  console.log(clients); // an array containing socket ids in 'room1' and/or 'room2'
});

// you can also use

io.in('room3').clients((err, clients) => {
  console.log(clients); // an array containing socket ids in 'room3'
});

this is from : https://github.com/socketio/socket.io-redis#redisadapterclientsroomsarray-fnfunction

answered Aug 02 '17 at 17:46

kevzettler

4,783
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1

This works so I accepted this as the correct answer. When you only run 1 node server it feels like overkill.. You need to run an extra redis server, only for having a list of connected clients. Wish there was an easier solution but i'll go for this one. It makes us ready to upscale to multiple node servers i guess. – Dries Cleymans Aug 03 '17 at 06:40
How do you keep track of user information with socket id ? A redis key value pair can be used but If the server restarts and a client reconnects, a new socket id is created and the old one remains in redis, causing a memory leak. – Koder Nov 15 '17 at 06:35

wrangler · Answer 2 · 2017-08-02T15:44:11.023

0

Try:

io.sockets.clients('room_name').forEach(function(item) {
    console.log(item.id);//any property of socket you want to print
});

Or you could try:

var clients = io.sockets.adapter.rooms['room_name'].sockets;
for (var clientId in clients ) {

     //this is the socket of each client in the room.
     var SocketofClient = io.sockets.connected[clientId];
     console.log(SocketofClient.id);
}

edited Aug 02 '17 at 15:44

answered Aug 02 '17 at 15:39

wrangler

3,454
1
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28

7

Those are not valid any longer in 2.0. I receive 'TypeError: fn.bind is not a function' for the first one and 'TypeError: Cannot read property 'sockets' of undefined' for the second solution. – Dries Cleymans Aug 02 '17 at 16:16

score 0 · Answer 3 · answered Jul 23 '19 at 10:04

Check this code which is run in socket.io 2.0

  io.sockets.in(roomID).clients(function(err, clients) {
                            clients.forEach(client => {
                                let user = io.sockets.connected[client];
                                console.log("Connected Client ", user.displayName);
                            });
                        });

socket.io 2.0 get connected clients in a room

3 Answers3