如何从nodejs向所有连接的客户端发送变量？

Question

我正在为学校做一个项目，我的想法是用聊天创建一个轮盘赌游戏，所以我正在使用nodejs和socket IO我的问题是如何发送服务器中生成的随机数的值给我的所有客户然后执行javascript函数来旋转轮盘赌？

app.js

    var express = require('express');
var path = require('path');
var debug = require('debug')('workspace:server');
var http = require('http');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var jquery = require('jquery');
var session = require('express-session')({
    secret: "secret",
    key: 'secret.sid',
    resave: true,
    saveUninitialized: true,
    cookie: {
        maxAge: 3600000
    }
});
var mysql      = require('mysql');
var connection = mysql.createConnection({
  host     : 'localhost',
  user     : 'root',
  password : 'password',
  database : 'database'
});

connection.connect();

connection.query('SELECT 1 + 1 AS solution', function(err, rows, fields) {
  if (err) throw err;

  console.log('The solution is: ', rows[0].solution);
});

connection.end();

var openid = require('openid');

var app = express();

var port = normalizePort(process.env.PORT || '3000');
app.set('port', port);

var server = http.Server(app);

var socket = require('socket.io')(server);
socket.on('connect', function(){});
socket.on('event', function(data){});
socket.on('disconnect', function(){});

server.listen(port);
server.on('error', onError);
server.on('listening', onListening);

function normalizePort(val) {
    var port = parseInt(val, 10);

    if (isNaN(port)) {
        // named pipe
        return val;
    }

    if (port >= 0) {
        // port number
        return port;
    }

    return false;
}

function onError(error) {
    if (error.syscall !== 'listen') {
        throw error;
    }

    var bind = typeof port === 'string' ? 'Pipe ' + port : 'Port ' + port;

    // handle specific listen errors with friendly messages
    switch (error.code) {
        case 'EACCES':
        console.error(bind + ' requires elevated privileges');
        process.exit(1);
        break;
        case 'EADDRINUSE':
        console.error(bind + ' is already in use');
        process.exit(1);
        break;
        default:
        throw error;
    }
}

function onListening() {
    var addr = server.address();
    var bind = typeof addr === 'string' ? 'pipe ' + addr : 'port ' + addr.port;
    console.log('Listening on ' + bind);
}

// 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(path.join(__dirname, 'public', 'favicon.ico')));
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(session);

function createRelyingParty(req) {
    var baseUrl = req.protocol + "://" + req.get("host");
    return new openid.RelyingParty(baseUrl + "/verify", baseUrl, true, false, []);
}

// for every request lets make the user session available to the templates
app.use(function(req, res, next) {
    res.locals.user = req.session.user;
    next();
});

app.get("/", function(req, res) {
    res.render('index', {
        title: 'Roulette',
        session: (typeof req.session.user !== 'undefined') ? req.session.user : ''
    });
});

socket.on('connection', function(socket){
  console.log('a user connected');
  socket.on('disconnect', function(){
    console.log('user disconnected');
});
});
socket.on('connection', function(socket){
  socket.on('chat message', function(msg){
    socket.emit('chat message', msg);
    console.log('message: ' + msg);
});
});

var r = require('./SpinGen');

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

// error handlers

// 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: {}
    });
});

SpinGen.js（js生成并向客户端发送号码）

    var express = require('express');
var http = require('http');
var app = express();
var server = http.Server(app);
var socket = require('socket.io')(server);

setInterval(function() {

    var rndNum = Math.floor((Math.random() * 34) + 0);

    var winningNum = rndNum;
    console.log(winningNum);
    socket.emit('roulette', winningNum);
},10000);

客户side.js

      var socket = io('http://localhost:3000');
  $('form').submit(function(){
    socket.emit('chat message', $('#m').val());
    $('#m').val('');
    return false;
  });
  socket.on('chat message', function(msg){
    $('#messages').append($('<li>').text(msg));
  });
  socket.on('roulette', function(spin){
    spinTo(spin);
  });
  socket.on('error', function(evData){
    console.error('Connection Error:',evData);
  });

Answer 1

尝试使用io.sockets.emit而不是socket.emit 。 这将向所有连接的客户端发出

Answer 2

您可以将随机数发送（发送）到所有连接的客户端 - 它看起来像这样：

io.emit('random number', randomNumber);

然后，您将在客户端监听事件，如下所示：

socket.on('random number', function(num){
    // num contains the random number

    // spin the wheel to the random number
   spinTo(num)
  });