nodejs+nowjs兑现聊天室 _JavaScript

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

引用

node app.js

在浏览器中访问http://localhost:8080

app.js

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 8080

nowjs = require 'now'

everyone = nowjs.initialize server

rooms = {}
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.room

updateRoomUser = (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 _users

everyone.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 newRoom

everyone.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.room

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}"
      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>&nbsp;&nbsp;" 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, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;")
</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"/>&nbsp;
    <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！"