nodeJS+express+Jade写一个局域网聊天应用(node基础)

var express = require(‘express‘);
var path = require(‘path‘);
var favicon = require(‘serve-favicon‘);
var logger = require(‘morgan‘);
var cookieParser = require(‘cookie-parser‘);
var bodyParser = require(‘body-parser‘);
var http = require("http");
var socketIo = require("socket.io");
var fs = require("fs");

var routes = require(‘./routes/index‘);
//var users = require(‘./routes/users‘);

var app = express();

// view engine setup
app.set(‘views‘, path.join(__dirname, ‘views‘));
app.set(‘view engine‘, ‘jade‘);

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + ‘/public/favicon.ico‘));
//app.use(‘port‘, process.env.PORT || 3000);
app.use(logger(‘dev‘));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, ‘public‘)));
app.use(‘/‘, routes);
//app.use(‘/users‘, users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
    var err = new Error(‘Not Found‘);
    err.status = 404;
    next(err);
});

// development error handler
// will print stacktrace
if (app.get(‘env‘) === ‘development‘) {
    app.use(function(err, req, res, next) {
        res.status(err.status || 500);
        res.render(‘error‘, {
            message: err.message,
            error: err
        });
    });
};

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render(‘error‘, {
        message: err.message,
        error: {}
    });
});
var server = http.createServer(app);
/*
var server = http.createServer(function(req, res){
    res.end("hehe");
});
 */
io = socketIo( server );

var clients = {};
var appUtil = require("util")._extend({},{
    getRandomId : function() {
        var i=0;
        i++;
        return function() {
            return "name"+(i++);
        }
    }(),
    read : function( callback ) {
        /*
         *   data.json保存的数据结构为 { key:[] Array };
         * */
        fs.readFile("data/data.json",function(err,data){
            data = data.toString();
            callback( JSON.parse(data).key );
        });
    },
    write : function( writeData ,callback ) {
        //读取数据并重写数据;
        this.read(function(data) {
            //我这个node读取单个json会返回一个a字符串，我就笑了，什么情况
            // 如果你直接把json放在数组里面就没有这个问题;
            //data = data[0] === "a" ? data.slice(1) : data;
            data.push( writeData );
            var temp = {
                key : data
            };
            fs.writeFileSync("data/data.json",JSON.stringify(temp));
            callback()
        });
    }
});

/*
 *   @desc WebSocket API, 端口3000, msg为对象:
 *   @param {  } 传递空对象会返回 {msg : 读取文件的结果 JSON, name : 随机的一个name};
 *   @param { name : "xx" , type : "get" , msg :  string }; //msg 读取文件的结果, type获取的类型
 *   @param { name : "xx" , type : "add" , msg : string }; //type 是 add为 添加, msg是指要添加的消息;
 */

 io.on(‘connection‘, function (socket) {
     socket.emit(‘open‘,"laile");//通知客户端已连接

     // 这个闭包内的工具方法;
     var sendMessage = function(name) {
         appUtil.read(function(data) {

             //给当前连接的用户发送sock消息
             socket.emit("message",{
                 name : name,
                 msg : data
             });
             //给非当前的所有用户发送消息;
             socket.broadcast.emit("message",{
                 name : name,
                 msg : data
             });
         });
     };

     socket.on(‘message‘, function(msg){
        console.log("来消息了");
        console.log(msg);
        //如果是没有name的,我们会分配一条name给用户;
         var name = msg.name || appUtil.getRandomId();

        if(!msg.name) {
            sendMessage( name );
            clients[name] = true;
        }else if(msg.type == "get") {
            sendMessage(name);
        }else if( msg.type == "add" ) {
            //我勒个去，因为readFile和appendFile是异步的, 所以要添加回调, 当然， 你可以用同步的readFileSync;
            appUtil.write({ time : new Date().toString(),  "name" : msg.name,  "msg" : msg.msg}, function(){
                sendMessage(name);
            });
        };

         //如果是新用户的话, 广播一条叫做新用户登陆的信息;
         console.log(name)
         if(!clients[name]) {
             clients[name] = true;
             console.log("广播新用户登录的消息");
             //注意 : 这个是socket,不是msg;
             socket.broadcast.emit("refreshUser",name);
         };
     });

     socket.on(‘disconnect‘, function (msg) {});
});

server.listen( 3000 , function() {
    console.log(" server is created ");
});



module.exports = app;