Is there a way to retrieve the io object within the io.sockets.on callback function?

My preference is to not alter my sockets method. I was hoping to be able to utilize the io object within the connected function.

Could this be a possibility?

function sockets (server) {
  const io = require('socket.io')(server);
  io.sockets.on('connection', connected);
}

const connected = (socket) => {
  socket.on('emit_to_all', data => {
    emitToAll(socket, data);

    // the same result could be achieved with
    // io.emit('emit_to_all', data);
  });
};

I searched on the github page here but none of the initial examples had a named callback function.

I stumbled upon the necessary documentation here.

Lastly, for details about the API, look at the documentation here.

Answer №1

Here is an example of how you can utilize sockets:

function establishSockets (server) {
  const io = require('socket.io')(server);
  io.sockets.on('connection', handleConnection(io));
}

const handleConnection = (io) => (socket) => {
  socket.on('emit_to_all', data => {
     broadcastToAll(socket, data);

     // The same functionality can be achieved with
     io.emit('emit_to_all', data);
  });
};

Answer №2

In order to ensure that the object is properly passed, you have two options: either pass it as a parameter or bind it to the context. If the closure syntax seems complex, using the bind method can simplify things for you.

For example:

    io.sockets.on('connection', connected.bind(io));

This way, in your connected function, the this keyword will refer to the 'io' object. Another approach is to pass the object as a parameter if you modify your function signature like so:

    io.sockets.on('connection', connected.bind(null, io));

    const connected = (io, socket) => {
      // Your logic here

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