Socket.io-在服务器和客户端之间同步数据

Question

第一次节点js，我正在编写一个应用程序，供我和朋友之间私人使用，我的朋友可以随时加入。

有可能让服务器有一个对象数组，例如带有n个项目的"franksLibrary"吗

用户可以阅读和修改"franksLibrary"吗？

目前我所做的是在用户网页中设置"franksLibrary"，并通过socket.io 发送franksLibrary和所有其他vars进行同步

index.js是服务器代码，index.html是交付给用户的

examle index.js

var http = require('http').createServer(app);
var io = require('socket.io')(http);
app.get('/', function(req, res){
res.sendFile(__dirname + '/index.html');
});
io.on('connection', function(socket){
socket.on('chat message', function(msg, usr){
io.emit('chat message',msg, usr);
});
});
http.listen(3000, function(){
console.log('listening on *:3000');
});

示例index.html:

var franksLibrary = [{
"book1":"title of book 1"
},
{
"book2":"title of book 2"
}];
socket.on('chat message', function(franksL /*,more variables*/){
franksLibrary = franksL
});
synch = function(){
socket.emit('chat message', franksLibrary /*,more variables*/);
}
removeBook = function(object, from){
var a = object;
var index = from.indexOf(a);
from.splice(index,1);
synch();
}

Answer 1

将franksLibrary从index.html移动到index.js。然后，在服务器上的connection回调中，将带有数据的chat message发送到新连接的客户端。

index.js

var franksLibrary = [{
"book1": "title of book 1"
},
{
"book2": "title of book 2"
}];
io.on('connection', function(socket) {
socket.emit('chat message', franksLibrary);
socket.on('chat message', function(data) {
franksLibrary = data;
socket.broadcast.emit('chat message', franksLibrary);
});
});

index.html

// initialize variable
var franksLibrary = [];
const socket = io();
socket.on('chat message', function(franksL) {
franksLibrary = franksL;
});
const synch = function(){
socket.emit('chat message', franksLibrary);
};
const removeBook = function(object, from) {
var a = object;
var index = from.indexOf(a);
from.splice(index,1);
synch();
};