nodejs+nowjs实现聊天室
支持多房间，支持私聊，使用nowjs库，服务器端代码不到100行。需要jquery1.7.1和coffee-script.js，读者可自行下载。
重点：
1、nowjs中Group的使用，如何遍历Group内的users。
2、客户端如何异步调用服务器端函数。
3、如何与特定用户通信。
运行
require('coffee-script');require('./chatroomserver');
chatroomserver.coffee
coffeescript代码，重点部分已加上注释
fs = require 'fs'url = require 'url'html = fs.readFileSync __dirname + '/chatroom.html'jquery = fs.readFileSync __dirname + '/../js/jquery-1.7.1.min.js'coffeescript = fs.readFileSync __dirname + '/../js/coffee-script.js'server = require('http').createServer((req, res)-> pathname = url.parse(req.url).pathname res.end html if pathname == '/' res.end jquery if pathname == '/jquery.js' res.end coffeescript if pathname == '/coffee-script.js')server.listen 8080nowjs = require 'now'everyone = nowjs.initialize serverrooms = {}rooms['lobby'] = '大厅'rooms['room1'] = '房间1'rooms['room2'] = '房间2'rooms['room3'] = '房间3'onlineUsers = {} #所有在线用户everyone.now.chckUser = (name, callback) -> #重点，使用异步方法调用 callback onlineUsers[name] != undefined #检查是否已有同名用户everyone.now.initlize = -> @now.updateRooms rooms @now.room = 'lobby' onlineUsers[@now.username] = @user.clientId _lobby = nowjs.getGroup @now.room _lobby.addUser @user.clientId _lobby.now.receiveMessage "[SYS]#{@now.username} 进入#{rooms[@now.room]}， 欢迎!" updateRoomUser @now.roomupdateRoomUser = (roomid) ->#更新房间的用户 _users = [] _group = nowjs.getGroup roomid _group.getUsers (usersid) ->#用Group#getUsers(callback)方法 _users = [] _users.push _group['users'][userid]['now']['username'] for userid in usersid #重点：取group中的用户名，要注意group的结构 _group.now.updateOnlineUsers _userseveryone.now.changeRoom = (newRoom) -> nowjs.getGroup(@now.room).removeUser(@user.clientId) nowjs.getGroup(@now.room).now.receiveMessage "[SYS]#{@now.username}离开#{rooms[@now.room]}进入#{rooms[newRoom]}，再见!" updateRoomUser @now.room nowjs.getGroup(newRoom).addUser(@user.clientId) @now.room = newRoom nowjs.getGroup(newRoom).now.receiveMessage "[SYS]#{@now.username} 进入#{rooms[newRoom]}，欢迎!" updateRoomUser newRoomeveryone.disconnected ->#当断开连接时，触发 nowjs.getGroup(@now.room).now.receiveMessage "[SYS]#{@now.username}走了，再见!" nowjs.getGroup(@now.room).removeUser(@user.clientId) delete onlineUsers[@now.username] updateRoomUser @now.roomeveryone.now.distributePersonalMessage = (to, message) -> #私聊 self = @ #保存this _gruop = nowjs.getGroup(@now.room) _gruop.hasClient onlineUsers[to], (bool) -> #判断用户是否在线，使用回调函数 if bool self.now.receiveMessage "我对#{to}说：#{message}" nowjs.getClient onlineUsers[to], -> this.now.receiveMessage "#{self.now.username}对我说：#{message}"#重点：如何跟特定用户通信 else self.now.receiveMessage "[ERR]#{to}不在这个房间！"everyone.now.distributeMessage = (message) -> nowjs.getGroup(@now.room).now.receiveMessage(message);chatroom.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head> <title>聊天室</title></head><script type="text/javascript" src="/jquery.js"></script><script src="/nowjs/now.js"></script><script src="/coffee-script.js"></script><script type="text/coffeescript"> now.receiveMessage = (message) -> $("div#talkFrame").append "<br>"+ message $(document).ready -> $('#login').click -> if $('#userName').val() == '' alert 'please input user name!' else now.chckUser $('#userName').val(), (exist)-> #重点：使用回调函数，异步调用的方式。 if exist alert '该用户已存在，请另取名字!' $('#userName').focus() else now.username = $('#userName').val() now.initlize() $('span#name').text("#{now.username}说：") $("#prePage").hide() $("#mainPage").show() $(document).on "click", "a.change", ->#点击房间名时进入房间。jquery对于动态创建元素的访问方式，此方式需要jquery1.7.+版本 now.changeRoom($(this).attr('id')) $('#currentName')[0].innerHTML = $(this).text() $(document).on "click", "a.users", -> #点击用户名时 $("input#message").val("@#{$(this).text()}:") $("input#message").focus() $(document).on "keydown", "input#message", (event)->#捕获回车 if event.keyCode==13 $('input#send').click() else $('input#send').click() if event.altKey and event.keyCode==83#Alt + s快捷键发送 $('input#send').click -> mess = $('input#message').val() if mess == '' return #head = "#{now.username} 说：" if mess[0] == '@' #私聊 if mess.search(':') == -1 alert '格式不对，对象名后面少了":"，请重新输入！' $("input#message").focus() return to = mess.substring 1, mess.search(':')#提取私聊对象 head = "#{now.username} 对 #{to} 说：" now.distributePersonalMessage to, utils.toStaticHTML mess.substring mess.search(':') + 1 $('input#message').val "@#{to}: " else now.distributeMessage "<a href='#' class='users'>#{now.username}</a> 说：#{utils.toStaticHTML mess}" $('input#message').val '' now.updateRooms = (rooms) -> $('div#rooms').empty() $('div#rooms').append "<a href='#' id = #{roomid} class='change'>#{rooms[roomid]}</a> " for roomid in Object.keys rooms now.updateOnlineUsers = (users) -> $('div#onlineUsers').empty() $('div#onlineUsers').append "<br/><a href='#' class='users'>#{user}</a>" for user in users utils = toStaticHTML: (text)-> inputHtml = text.toString() inputHtml.replace(/&/g, "&").replace(/</g, "<").replace(/>/g, ">")</script><body><div id='prePage' class='page' style='width:690px;text-align:center;'> <input id='userName' type='text' placeholder="请输入您的昵称"/> <input id='login' type='button' value='进入聊天室'/></div><div id='mainPage' class='page' style='display:none;'> <div style='overflow:hidden;'> <div class='talkLeft'> <h2 id='currentName' style='text-align:center;'>大厅</h2> <div id='talkFrame'></div> <div id='inputDiv'> <span id ="name"></span><input type="text" placeholder="嗨，随便说点啥呗" id="message" size="20"></textarea> </div> <div> <input class='f-right' type='button' value='发送' id="send"/> </div> </div> <div class='talkRight'> <div id='onlineUsers'></div> </div> <div id = 'rooms' style='text-align:center;'> </div> </div></div></body></html>网页有部分借鉴https://github.com/auzll/nodechat。
附加信息，有兴趣的读者可以自己尝试：
Group有Group#hasClient = function (clientId, callback)判断用户是否在组里，但是没类似Now#getClient = function (clientId, callback)。Group#getClient应该很有用，能不能自己加上去呢？找到now\lib\gruop.js文件，添加下面的代码：
Group.prototype.getClient = function (clientId, callback) { callback.apply(this.users[clientId]);};于是服务端私聊部分的代码可写成：
everyone.now.distributePersonalMessage = (to, message) -> #私聊 self = @ #保存this _gruop = nowjs.getGroup(@now.room) _gruop.hasClient onlineUsers[to], (bool) -> #判断用户是否在线，使用回调函数 if bool self.now.receiveMessage "我对#{to}说：#{message}" _gruop.getClient onlineUsers[to], -> this.now.receiveMessage "#{self.now.username}对我说：#{message}"#重点：如何跟特定用户通信 else self.now.receiveMessage "[ERR]#{to}不在这个房间！"