NodeJS socket.io in a router page - node.js

Question

I have the app.js code:
var express = require('express');
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io')(server);
io.on('connection', function(socket){
socket.on('newRideAdded', function(exclude){
io.emit('newRideAdded', exclude);
});
console.log('a user connected');
socket.on('disconnect', function(){
console.log('user disconnected');
});
});
var bodyParser = require('body-parser');
app.use(bodyParser.json()); // support json encoded bodies
app.use(bodyParser.urlencoded({ extended: true })); // support encoded bodies
app.use(express.static(__dirname + '/public/'));
app.use('/rides', require('./routes/rides'));
app.use('/user', require('./routes/user'));
server.listen("8080", function() {
console.log("Connected to db and listening on port 8080");
});
And I want to move the socket io code to its router's page.
That is the router page:
var express = require('express');
var router = express.Router();
var mongojs = require('mongojs');
var db = mongojs("ride4you", []);
router.post('/getRides', function(req, res, next) {
db.rides.find(function(err, docs) {
res.json(docs);
});
});
// rest of the restapi in this page.
// I want socket code to be here
module.exports = router;
As you can see i have each socket emits in each router's page and I already have module.exports in routers page.
How can it be done?
Thanks.

Answer 1

Using Express 4, in your app.js file you can use
app.set('socketio', io);
Then in your router or controller, you can use
router.post('/getRides', function(req, res, next) {
var io = req.app.get('socketio');
io.to(//socket.id//).emit("message", data);
db.rides.find(function(err, docs) {
res.json(docs);
});
};
This is a clean way of passing the reference along.