normalValidation.js

//handles audio information of clients, eg. codecs they can play
module.exports = function(availClients, unavailClients, io) {
    var util = require('util');
    
    //for each connection
    io.sockets.on('connection', handleConnection);
    function handleConnection (socket) {
        
        //fired when the client discovered it's codec capabilities
        socket.on('codecCapability', function (mp3, mp4, ogg) {
            //validate input (can be either 'probably', 'maybe' or ''
            if  (   (mp3 !== 'probably' && mp3 !== 'maybe' && mp3 !== '')
                ||  (mp4 !== 'probably' && mp4 !== 'maybe' && mp4 !== '')
                ||  (ogg !== 'probably' && ogg !== 'maybe' && ogg !== '')) {
                return;
            }
            
            //get the name of this socket and continue
            var name = socket.get('name', function (err, name) {
                if (err) {
                    util.debug('Error: could not get name of socket');
                    return;
                }
                
                //get this client
                var thisClient = unavailClients[name];
                if (!thisClient) thisClient = availClients[name];
                if (!thisClient) {
                    util.debug('Error: client could not be located.');
                    return;
                }
                
                //update client's capability list
                thisClient.audioCapabilityList = {
                        mp3: mp3
                      , mp4: mp4
                      , ogg: ogg
                };
                
                //debug
                util.debug('set capability list of client to: ' + util.inspect(thisClient.audioCapabilityList));
            });
        });
    }
};

normalVersion.js

module.exports = function(io) {
    var util = require('util'),
        Step = require('step');
    
    //for each connection
    io.sockets.on('connection', function (socket) {
        
        //fired when the client discovered it's codec capabilities
        socket.on('codecCapability', function (mp3, mp4, ogg) {
            //validate input
            
            //get the name of this socket and continue
            var name = socket.get('name', function (err, name) {
                //update capability list
            });
        });
    }
};

stepVersion.js

module.exports = function(io) {
    var util = require('util'),
        Step = require('step');
    
    Step(
        function onConnection() {
            io.sockets.on('connection', this);
        },
        function handleConnection(socket) {
            socket.on('codecCapability', this);
        },
        function setCodecCapabilityForSocket(mp3, mp4, ogg) {
            //validate input
            
            socket.get('name', function(err, name) {
                this(err, name, mp3, mp4, ogg);
            });
        },
        function setCodecCapabilityForName(err, name, mp3, mp4, ogg) {
            //update client's capability list
        }
    );
};