Node.js: get server variable in app.js with different structure

Question

So I downloaded a MEAN-stack skeleton and I am making a movie app to practice my skills. I wanted to add a chat room, but on the server side I don't quite know what to do.

This is is the code they normally expect:

var app = express();
var server = app.listen(3000, function(){
    console.log('now listening for requests on port 3000')
});


var io = socket(server);

io.on('connection', function(socket){
    console.log('made socket connection')
});

The problem is that the skeleton I downloaded starts up the server in a different way (I think they do it with the 'www'-file below), so I don't think I can use

var server = app.listen(3000, function(){
        console.log('now listening for requests on port 3000')
    });

to get that server variable that I then want to enter in

var io = socket(server)

How do I get that server variable in my case? I'll also post the www file below. I don't understand much of it, but it does seem to have a server variable.

#!/usr/bin/env node

/**
 * Module dependencies.
 */

var app = require('../app');
var debug = require('debug')('angular2-nodejs:server');
var http = require('http');

/**
 * Get port from environment and store in Express.
 */

var port = normalizePort(process.env.PORT || '3200');
app.set('port', port);

/**
 * Create HTTP server.
 */

var server = http.createServer(app);

/**
 * Listen on provided port, on all network interfaces.
 */

server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

/**
 * Normalize a port into a number, string, or false.
 */

function normalizePort(val) {
  var port = parseInt(val, 10);

  if (isNaN(port)) {
    // named pipe
    return val;
  }

  if (port >= 0) {
    // port number
    return port;
  }

  return false;
}

/**
 * Event listener for HTTP server "error" event.
 */

function onError(error) {
  if (error.syscall !== 'listen') {
    throw error;
  }

  var bind = typeof port === 'string'
    ? 'Pipe ' + port
    : 'Port ' + port;

  // handle specific listen errors with friendly messages
  switch (error.code) {
    case 'EACCES':
      console.error(bind + ' requires elevated privileges');
      process.exit(1);
      break;
    case 'EADDRINUSE':
      console.error(bind + ' is already in use');
      process.exit(1);
      break;
    default:
      throw error;
  }
}

/**
 * Event listener for HTTP server "listening" event.
 */

function onListening() {
  var addr = server.address();
  var bind = typeof addr === 'string'
    ? 'pipe ' + addr
    : 'port ' + addr.port;
  debug('Listening on ' + bind);
}

Answer 1

I'll try to point out some of what you are looking for and where to put the socket.io code to start.

/* don't add this section
    var app = express();
    var server = app.listen(3000, function(){
        console.log('now listening for requests on port 3000')
    });
*/
//---------------------------------------------------
// equal to the following section of your www file
var app = require('../app');
var debug = require('debug')('angular2-nodejs:server');
var server = http.createServer(app);

/**
 * Listen on provided port, on all network interfaces.
 */

server.listen(port);
server.on('error', onError); // onError function defined below this code
server.on('listening', onListening);// onListening function defined below this code

// put the soket.io code here after server is listening on your port
var io = require('socket.io')(server);// create the socket.io object here and pass the server object

io.on('connection', function(socket){
     console.log('made socket connection')
});