how to organize socket handling in node.js and socket.io app

node.js, socket.io, sockets, websocket

Solution

To organize your event handlers in different files, you could use a structure like this:

./main.js

var io = require('socket.io');
var Chat = require('./EventHandlers/Chat');
var User = require('./EventHandlers/User');

var app = {
    allSockets: []
};

io.sockets.on('connection', function (socket) {

    // Create event handlers for this socket
    var eventHandlers = {
        chat: new Chat(app, socket),
        user: new User(app, socket)
    };

    // Bind events to handlers
    for (var category in eventHandlers) {
        var handler = eventHandlers[category].handler;
        for (var event in handler) {
            socket.on(event, handler[event]);
        }
    }

    // Keep track of the socket
    app.allSockets.push(socket);
});

./EventHandlers/Chat.js

var Chat = function (app, socket) {
    this.app = app;
    this.socket = socket;

    // Expose handler methods for events
    this.handler = {
        message: message.bind(this) // use the bind function to access this.app
        ping:    ping.bind(this)    // and this.socket in events
    };
}

// Events

function message(text) {
    // Broadcast message to all sockets
    this.app.allSockets.emit('message', text);
});

function ping() {
    // Reply to sender
    this.socket.emit('message', 'PONG!');
});

module.exports = Chat;

Problem

For my REST api I have create a file for each route. ``` app.get('/api/user', routes.user.index); app.get('/api/user/login', routes.user.login); ``` etc, etc. Now I'm introducing socket.io to the backend and it seems I can only call one function for all socket events. ``` var socket = require('./socket/stuff.js'); io.sockets.on('connection', function(sock){ socket.stuff(sock, io); }); ``` How should I break up the `./socket/stuff.js` file (which exports `stuff`). Into separate files. I would like to eventually replace my REST api with sockets, but I don't want everything to be in one file. I imagine I would have: ``` ./socket/chat.js ./socket/user.js ``` etc. etc.

Original source