chat-server.js

// http://ejohn.org/blog/ecmascript-5-strict-mode-json-and-more/
"use strict";

// Optional. You will see this name in eg. 'ps' or 'top' command
process.title = 'node-chat';

// Port where we'll run the websocket server
var webSocketsServerPort = 1337;

// websocket and http servers
var webSocketServer = require('websocket').server;
var http = require('http');

/**
 * Global variables
 */
// latest 100 messages
var history = [ ];
// list of currently connected clients (users)
var clients = [ ];

/**
 * Helper function for escaping input strings
 */
function htmlEntities(str) {
    return String(str).replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
}

// Array with some colors
var colors = [ 'red', 'green', 'blue', 'magenta', 'purple', 'plum', 'orange' ];
// ... in random order
colors.sort(function(a,b) { return Math.random() > 0.5; } );

/**
 * HTTP server
 */
var server = http.createServer(function(request, response) {
    // Not important for us. We're writing WebSocket server, not HTTP server
});
server.listen(webSocketsServerPort, function() {
    console.log((new Date()) + " Server is listening on port " + webSocketsServerPort);
});

/**
 * WebSocket server
 */
var wsServer = new webSocketServer({
    // WebSocket server is tied to a HTTP server. WebSocket request is just
    // an enhanced HTTP request. For more info http://tools.ietf.org/html/rfc6455#page-6
    httpServer: server
});

// This callback function is called every time someone
// tries to connect to the WebSocket server
wsServer.on('request', function(request) {
    console.log((new Date()) + ' Connection from origin ' + request.origin + '.');

    // accept connection - you should check 'request.origin' to make sure that
    // client is connecting from your website
    // (http://en.wikipedia.org/wiki/Same_origin_policy)
    var connection = request.accept(null, request.origin); 
    // we need to know client index to remove them on 'close' event
    var index;;
    var userName = false;
    var userColor = false;

    console.log((new Date()) + ' Connection accepted.');

    // send back chat history
    if (history.length > 0) {
        connection.sendUTF(JSON.stringify( { type: 'history', data: history} ));
    }

    // user sent some message
    connection.on('message', function(message) {
        if (message.type === 'utf8') { // accept only text
            if (userName === false) { // first message sent by user is their name
                // remember user name
                userName = htmlEntities(message.utf8Data);
                // get random color and send it back to the user
                userColor = colors.shift();
                connection.sendUTF(JSON.stringify({ type:'color', data: userColor }));
                console.log((new Date()) + ' User is known as: ' + userName + ' with ' + userColor + ' color.');

                index = clients.push({userName: userName, connection: connection}) - 1;
            }
            else { // log and broadcast the message
                console.log((new Date()) + ' Received Message from ' + userName + ': ' + message.utf8Data);

                // we want to keep history of all sent messages
                var obj = {
                    time: (new Date()).getTime(),
                    text: htmlEntities(message.utf8Data),
                    author: userName,
                    color: userColor
                };


                if (obj.text.startsWith("/귓말 ")) {
                    var tmpMsgArr = obj.text.split(/\s/);
                    var toUserName = tmpMsgArr[1];
                    var fromUserName = userName;
                    var json;

                    clients.filter(function (d) {return d.userName == toUserName;}).forEach(function(v, i) {
                        tmpMsgArr.splice(0,2);
                        obj.text = "[" + toUserName + "에게 귓말]" + tmpMsgArr.join(" ");
                        json = JSON.stringify({ type:'message', data: obj});
                        connection.sendUTF(json);
                        obj.text = "[귓말]" + tmpMsgArr.join(" ");
                        json = JSON.stringify({ type:'message', data: obj});
                        v.connection.sendUTF(json);
                    });
                }
                else {
                    history.push(obj);
                    history = history.slice(-100);

                    var json = JSON.stringify({ type:'message', data: obj});
                    // broadcast message to all connected clients
                    for (var i=0; i < clients.length; i++) {
                        clients[i].connection.sendUTF(json);
                    }
                }
            }
        }
    });

    // user disconnected
    connection.on('close', function(connection) {
        if (userName !== false && userColor !== false) {
            console.log((new Date()) + " Peer " + connection.remoteAddress + " disconnected.");
            // remove user from the list of connected clients
            clients.splice(index, 1);
            // push back user's color to be reused by another user
            colors.push(userColor);
        }
    });

});