如何使用koa实现socket.io官网的例子
socket.io官网中使用express实现了一个最简单的IM即时聊天,今天我们使用koa来实现一下
### 框架准备
- 确保你本地已经安装好了nodejs和npm,使用koa要求node版本>7.6
- 在你需要的位置新建一个文件夹(官网的简单命名为chat-example)
- 进入项目目录,创建package.json文件:
{
"name": "socket-chat-example",
"version": "0.0.1",
"description": "my first socket.io app",
"dependencies": {}
}
4.命令行中使用npm安装,执行以下命令
npm install --save koa koa-router http fs socket.io
### 接下来直接上代码
项目目录下直接新建index.js
var Koa = require('koa');
var app = new Koa();
const Router = require('koa-router');
const fs = require('fs');
const server = require('http').createServer(app.callback());
const io = require('socket.io')(server);
// 首页路由
let router = new Router();
router.get('/', ctx => {
ctx.response.type = 'html';
ctx.response.body = fs.createReadStream('./index.html');
});
app.use(router.routes());
// socket连接
io.on('connection', (socket) => {
socket.on('chat message', (msg) => {
console.log('message: '+msg);
io.emit('chat message', msg);
});
socket.on('disconnect', () => {
console.log('user disconnected');
});
});
// 监听端口
server.listen(3000, () => {
console.log('listening on *:3000');
});
重点:
- socket的连接方式是先建立server,它的获取方式不再是:
var http = require('http').Server(app);
var io = require('socket.io')(http);
而变成了:
const server = require('http').createServer(app.callback());
const io = require('socket.io')(server); - node8之后,function(){} 可以简化为 () => {},写法上更加的简洁
页面index.html
<!doctype html>
<html>
<head>
<title>Socket.IO chat</title>
<style>
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font: 13px Helvetica, Arial; }
form { background: #000; padding: 3px; position: fixed; bottom: 0; width: 100%; }
form input { border: 0; padding: 10px; width: 90%; margin-right: .5%; }
form button { width: 9%; background: rgb(130, 224, 255); border: none; padding: 10px; }
#messages { list-style-type: none; margin: 0; padding: 0; }
#messages li { padding: 5px 10px; }
#messages li:nth-child(odd) { background: #eee; }
</style>
</head>
<body>
<ul id="messages"></ul>
<form action="">
<input id="m" autocomplete="off" /><button>Send</button>
</form>
<script src="/socket.io/socket.io.js"></script>
<script src="https://code.jquery.com/jquery-1.11.1.js"></script>
<script>
$(function () {
var socket = io();
$('form').submit(function(){
socket.emit('chat message', $('#m').val());
$('#m').val('');
return false;
});
socket.on('chat message', function(msg){
$('#message').append($('<li>').text(msg));
});
});
</script>
</body>
</html>
index.html和官网的一样,不做任何改动