NodeJS导出不按预期工作

Question

我遇到了nodeJS导出理解问题......我将解释这个问题：

我试图将我/ bin / www文件中的变量导出到我的index.js文件中：

/ bin中/万维网

   #!/usr/bin/env node

/**
 * Module dependencies.
 */

var app = require('../app');
var debug = require('debug')('chat:server');
var http = require('http');

/**
 * Get port from environment and store in Express.
 */

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

/**
 * Create HTTP server.
 */

var server = http.createServer(app);
var io = require('socket.io')(http).listen(server);
module.exports.io = io;
console.log("FROM WWW FILE: " + exports.io);



/**
 * Listen on provided port, on all network interfaces.
 */

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

/**
 * Normalize a port into a number, string, or false.
 */

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

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

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

  return false;
}

/**
 * Event listener for HTTP server "error" event.
 */

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;
  }
}

/**
 * Event listener for HTTP server "listening" event.
 */

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

我试图在index.js中获取该变量：

index.js

   var express = require('express');
var router = express.Router();
var www = require('../bin/www');

console.log("FROM INDEX.JS WWW OBJECT:" + www);

console.log("WWW.IO VARIABLE FROM INDEX.JS:" + www.io); //UNDEFINED ?

/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});

//io.on('connection', function (socket) {
 // console.log("CONEXION ESTABLECIDA");
  //socket.emit('news', { hello: 'world' });
  //socket.on('my other event', function (data) {
   // console.log(data.my);
  //});
//});



module.exports = router;



console.log("IO IS:" + www.io); //UNDEFINED ?

我不确定为什么www.io未定义，我确定非常明显，但无法理解......

如果你能伸出援助之手我会很感激。

非常感谢！