node.js 中的导出和模块导出

Question

我在主根目录下有一个文件

test_file.js

下面是里面的代码

var config = require('config');
var Ctrl = require('./Controllers');
var port = process.env.PORT || config.get("PORT") || 3000;
var cors = require('cors');
var express = require('express');  
var app = express();
var router = express.Router();

app.use(cors());

app.use(router);
var server = require('http').createServer(app); 

var io = require('socket.io')(server, {'pingInterval': 4000, 'pingTimeout': 6000});

io.on('connection', Ctrl.connection);

console.log("Opening at port " + port);
server.listen(port, function () {
});

module.exports = router;
require('./Routes')();

我在路径

中有另一个文件

/Controllers/index.js

我也想把io传给index.js，这是代码

    var Promise = require('q').Promise;
    var config  = require('config');
    var mysql   = require('mysql');

/// I want to get var io = require('../test_file.js');

    /**Initialization socket connection */
    exports.connection = function (socket) {
        if (!(socket.handshake.query.accountType != null && socket.handshake.query.id != null && socket.handshake.query.accessKey != null
            && socket.handshake.query.id > 0)) {
            socket.disconnect();
            return;
        }

现在我对 module.exports 和导出感到困惑，我的 module.exports 已经传递到另一个文件，我想添加另一个变量，即 io 并将其传递到控制器文件.我该怎么做

回复查询，

app.use(router);
var server = require('http').createServer(app); 

var io = require('socket.io')(server, {'pingInterval': 4000, 'pingTimeout': 6000});
module.exports = {
  router: router,
  io: io
};

io.on('connection', Ctrl.connection);

console.log("Opening at port " + port);
server.listen(port, function () {
});

require('./Routes')();

在Controllers/index.js

var Promise = require('q').Promise;
var config  = require('config');
var mysql   = require('mysql');

var Driver  = require('./driver');
var User    = require('./user');

var io = require('../test_file.js').io;
console.log("logging");
console.log(io);

结果是{} for io

Answer 1

exports is just module.exports's little helper. Your module returns module.exports to the caller ultimately, not exports. All exports does is collect properties and attach them to module.exports IF module.exports doesn't have something on it already. If there's something attached to module.exports already, everything on exports is ignored.

您可以将两者都作为对象传递

 module.exports = {
  router: router,
  io: io
};

Please refer this doc for more explanation

编辑

通过module.exports

访问对象

file.js

var express = require('express');
var router = express.Router();

/* GET users listing. */
router.get('/', function(req, res, next) {
  res.send('respond with a resource');
});

module.exports = {router:router};

使用

访问它

var router=require('./file').router
   OR

var router=require('./file');

router.router

node.js 中的导出和模块导出

Exporting and module exporting in node.js

javascript

node.js

promise

q