一直想做一个即时聊天的应用，前几天看到了socket.io,感觉还不错。自己略加改动，感觉挺不错的。官网上给的样例非常easy，以下改进了一点，实现了历史消息的推送。
demo地址:chat.codeboy.me
当中server端代码:
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var history = new Array();
app.get('/', function(req, res){
res.sendfile('chat.html');
});
io.on('connection', function(socket){
socket.on('chat message', function(msg){
io.emit('chat message', msg);
addMsg(msg);
});
socket.on('login message', function(msg){
socket.join('history room');
for(var i=0;i<history.length;i++){
io.in('history room').emit('chat message', history[i]);
}
io.in('history room').emit('chat message', 'lyd__上面是近期的一些信息');
socket.leave('history room');
socket.join('chat room');
io.emit('chat message',msg);
addMsg(msg);
});
});
http.listen(3000, function(){
console.log('listening on *:3000');
});
function addMsg(msg){
history.push(msg);
if(history.length>100)
history.shift();
};聊天页面代码：
<!doctype html>
<html>
<head>
<title>聊天室</title>
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font: 20px Helvetica, Arial; }
form { background: #000; padding: 3px; position: fixed; bottom: 0; 100%; }
form input { border: 0; padding: 10px; 90%; }
form button { 10%; background: rgb(130, 224, 255); border: none; padding: 10px; }
#messages { list-style-type: none; margin: 0; padding: 0; }
#messages li { padding: 5px 10px 5px 10px; }
</style>
</head>
<body>
<ul id="messages"></ul>
<form action="">
<input id="m" autocomplete="off" /><button id="btn">登录</button>
</form>
<script src="/socket.io/socket.io.js"></script>
<script src="http://code.jquery.com/jquery-1.11.1.js"></script>
<script>
var socket = io();
var login =true;
var username = "" ;
var myDate = new Date();
$('form').submit(function(){
if(login){
username = $('#m').val();
if(username.length==0){
alert("请输入用户名");
return false;
}
login = false ;
socket.emit('login message', "lyd__<font color=blue>"+username + '</font>增加了聊天室 '+myDate.getMonth()+"-"+myDate.getDate()+" "+myDate.getHours()+":"+myDate.getMinutes()+":"+myDate.getSeconds());
$('#btn').html("发送");
}else {
socket.emit('chat message', username +"##"+ $('#m').val());
}
$('#m').val('');
return false;
});
socket.on('chat message', function(msg){
var item = msg.split("##",2);
if(msg.indexOf('lyd__')==0)
$('#messages').append('<li style="text-align:center; font-size:12px;margin-top:1px; color:red; background-color:#eee;">' +msg.substr(5)+'</li>');
else if(msg.indexOf(username)==0){
$('#messages').append('<li style="text-align:right; font-size:12px; color:red;">'+item[0]+':</li>');
$('#messages').append('<li style="text-align:right;padding-top:0px; padding-left:30%;color:purple;">'+item[1]+'</li>');
}else {
$('#messages').append('<li style="text-align:left;font-size:12px; color:red;">'+item[0]+':</li>');
$('#messages').append('<li style="text-align:left;padding-top:0px; padding-right:30%; color:purple;">'+item[1]+'</li>');
}
});
</script>
</body>
</html>这样就实现了一个聊天室，进入后输入username，登录，之后server返回近期的100条消息。