Configuring Express 4.0 routes with socket.io

Question

I have created a new Express application. It generated app.js for me and I have then created the following index.js bringing in socket.io:

var app = require('./app');

server=app.listen(3000);



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

var socket = io.listen(server, { log: false });



socket.on('connection', function (client){

    console.log('socket connected!');

});

Can anyone advise how I would access socket.io within the routes files?

For reference, the default generated app.js is below:

var express = require('express');

var path = require('path');

var favicon = require('static-favicon');

var logger = require('morgan');

var cookieParser = require('cookie-parser');

var bodyParser = require('body-parser');



var routes = require('./routes/index');

var users = require('./routes/users');



var app = express();



// view engine setup

app.set('views', path.join(__dirname, 'views'));

app.set('view engine', 'jade');



app.use(favicon());

app.use(logger('dev'));

app.use(bodyParser.json());

app.use(bodyParser.urlencoded());

app.use(cookieParser());

app.use(express.static(path.join(__dirname, 'public')));



app.use('/', routes);

app.use('/users', users);



/// catch 404 and forwarding to error handler

app.use(function(req, res, next) {

    var err = new Error('Not Found');

    err.status = 404;

    next(err);

});



/// error handlers



// development error handler

// will print stacktrace

if (app.get('env') === 'development') {

    app.use(function(err, req, res, next) {

        res.status(err.status || 500);

        res.render('error', {

            message: err.message,

            error: err

        });

    });

}



// production error handler

// no stacktraces leaked to user

app.use(function(err, req, res, next) {

    res.status(err.status || 500);

    res.render('error', {

        message: err.message,

        error: {}

    });

});





module.exports = app;

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Answer 1

SocketIO does not work with routes it works with sockets.

That said you might want to use express-io instead as this specially made for this or if you are building a realtime web app then try using sailsjs which already has socketIO integrated to it.

Do this to your main app.js

app = require('express.io')()
app.http().io()

app.listen(7076)

Then on your routes do something like:

app.get('/', function(req, res) {
    // Do normal req and res here
    // Forward to realtime route
    req.io.route('hello')
})

// This realtime route will handle the realtime request
app.io.route('hello', function(req) {
    req.io.broadcast('hello visitor');
})

See the express-io documentation here.

Or you can do this if you really want to stick with express + socketio

On your app.js

server = http.createServer(app)
io = require('socket.io').listen(server)
require('.sockets')(io);

Then create a file sockets.js

module.exports = function(io) {

    io.sockets.on('connection', function (socket) {
        socket.on('captain', function(data) {
            console.log(data);
            socket.emit('Hello');
        });
    });
};

You can then call that to your routes/controllers.

Configuring Express 4.0 routes with socket.io

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