NodeJS, socketIO, multiple files

Question

I'm a little bit confused;

I would like to use socketIO on NodeJS app. I've created this (pseudo)code:

//server.js
var app = express();
//some code...
var router = require('./app/router');
app.use(router);

var server = app.listen(appConfig.app.port, function () {
    var port = server.address().port;
});
var io = require('socket.io')(server);
io.on('connection', function (client) {
    console.log('Client connected...');

    client.on('join', function (data) {
        console.log(data);
    });
});


//client.js
var socket = io.connect('http://localhost:5555');
socket.on('connect', function(data) {
    socket.emit('join', 'Hello World from client');
});

Everything is fine. But !

At now, I would like to emit event in another file. I have router and POST request. I want to emit event on POST request (request handler is in another file).

//router.js
router.route("/addmenu").post(function (req, res) {
        menuModel.addMenu(req.body,function(data){
            //I WANT EMIT HERE
            res.json(data)
        });
    };
);

I have to initialize router before start server, but I have to pass server to IO... How pass IO to router ?

Answer 1

You can try this

//server.js
var app = express();
//some code...
var io;
var getIOInstance = function(){
  return io;
};
var router = require('./app/router')(getIOInstance);
app.use(router);

var server = app.listen(appConfig.app.port, function () {
    var port = server.address().port;
});

io = require('socket.io')(server);
io.on('connection', function (client) {
    console.log('Client connected...');

    client.on('join', function (data) {
        console.log(data);
    });
});

---

//router.js
module.exports = function(getIOInstance){
    router.route("/addmenu").post(function (req, res) {
        menuModel.addMenu(req.body,function(data){
            //I WANT EMIT HERE
            getIOInstance().sockets.emit(...)
            res.json(data)
        });
    };
    return router;
);

This solution will work if you want to 'notify' all connected clients.

If you need to notify only a specific client, then I will advise you to use an event-emitter module in order to communicate these events and not share your socket instances across multiple files.

Answer 2

In router.js you can do something like:

//router.js
module.exports = function(io) {
var router = //What you declared it to be
router.route("/addmenu").post(function (req, res) {
    menuModel.addMenu(req.body,function(data){
        //I WANT EMIT HERE
        res.json(data)
    });
};
);
return router;
}


 //server.js
 //Change this line to be like the one below
var router = require('./app/router');
//.........
//.......

//Desired way
var router = require('./app/router')(io);