在Socket.IO中未正确分配房间名称

Question

Upon a button being pressed client-side, a socket.emit is called with the parameter being defined by an input box. Here's the server-side socket.on :

socket.on('createRoom', function(roomName) {
  socket.join('Room 1');
  console.log(io.sockets.adapter);
  console.log(io.sockets.adapter.rooms);
  let clients = io.sockets.adapter.rooms['Room 1'].sockets;
  console.log('A user joined the room with the name: ' + roomName + ". The user's name is " + raceResponse.user_name);
  console.log(clients);
  socket.emit('roomCreated', clients);
});

I have since changed this to have the room name defined server-side, as I was getting an error:

let clients = io.sockets.adapter.rooms['Room 1'].sockets;
TypeError: Cannot read property 'sockets' of undefined

But notice the lines above it: they log io.sockets.adapter and io.sockets.adapter.rooms . I believe the latter is a list of all rooms, because it gives me:

{ ZJ81Hw0FkCIQxg86AAAA: [], UoE9k4lTnGMUB9y6AAAB: [], 'Y-Tr2j9MxCzZokSSAAAC': [ 'Y-Tr2j9MxCzZokSSAAAC': true ] }

What this looks like to me is that the first item in the object is the default room, and the other item is the room that was just created, which has one user in. What's confusing me is that the room is not called 'Room 1', which is what I would expect it to be.

I may have completely misinterpreted what io.sockets.adapter.rooms means, so if that is the case please let me know.

io.sockets.adapter gives me:

Adapter {
  nsp: Namespace {
    name: '/',
    server: Server {
      nsps: [Object],
      _path: '/socket.io',
      _serveClient: true,
      _adapter: [Function: Adapter],
      _origins: '*:*',
      sockets: [Circular],
      eio: [Server],
      httpServer: [Server],
      engine: [Server]
    },
    sockets: [ [Socket] ],
    connected: { wKTl5kLVfhWSTSt0AAAB: [Socket] },
    fns: [],
    ids: 0,
    acks: {},
    adapter: [Circular]
  },
  rooms: {
    '-zzOKEUrvDOj_345AAAA': [],
    wKTl5kLVfhWSTSt0AAAB: [ wKTl5kLVfhWSTSt0AAAB: true ]
  },
  sids: { wKTl5kLVfhWSTSt0AAAB: { wKTl5kLVfhWSTSt0AAAB: true } },
  encoder: Encoder {}
}
{
  '-zzOKEUrvDOj_345AAAA': [],
  wKTl5kLVfhWSTSt0AAAB: [ wKTl5kLVfhWSTSt0AAAB: true ]
}

Can anyone provide any explanation or alternative method of doing this? It would be much appreciated.

Answer 1

Not knowing your version of Socket-io but when the server is set up like:

let io = require('socket.io');

io.on('connection', function(socket){
    socket.join('Test');
    socket.join('Test1');
    console.log(io.sockets.adapter.rooms);
});

And the client is set up like:

let io = require('socket.io-client');

socket = io.connect("http://localhost:8090")

The result that I get from the server on Nodejs v8.9.3 / Socket.io v2.2.0:

{
    c9kG4WD5hFlLUOZrAAAA: Room { sockets: { c9kG4WD5hFlLUOZrAAAA: true }, length: 1 },
    Test: Room { sockets: { c9kG4WD5hFlLUOZrAAAA: true }, length: 1 },
    Test2: Room { sockets: { c9kG4WD5hFlLUOZrAAAA: true }, length: 1 }
}

Digging through Socket.IO documentation I found a reference to a method to show all of the rooms a socket is in and tested that:

let rooms = Object.keys(io.sockets.adapter.rooms);
console.log(rooms);

Which returned:

[ 'c9kG4WD5hFlLUOZrAAAA', 'Test', 'Test2' ]

Which is an array of all the currently existing rooms by name only.

I sort of refined that with:

let roomName = rooms[rooms.length-1]; //Get last room pushed
console.log('A user joined the room with the name: ' + roomName + ". The user's name is X");

Which returned:

"A user joined the room with the name: Room 1. The user's name is X"

You could track the names of the rooms yourself in an array, but you would want to be careful as that could introduce a potential memory leak.

But if all you want is the very last room joined, you could just use whatever value as a var and pass that through the emit.