How to call express 4.0 middleware function in app.js from router?

Question

How to call express 4.0 middleware function in app.js from router?

I have a middleware function to do the basic authorization which is in app.js (starter javascript). But there are a few router files in other javascript files. My question is how I can call the authorization middleware function in my router?

Here is my app.js:

var basicAuth = require('basic-auth');

var auth = function (req, res, next) {
  function unauthorized(res) {
    res.set('WWW-Authenticate', 'Basic realm=Authorization Required');
    return res.send(401);
  };

  var user = basicAuth(req);

  if (!user || !user.name || !user.pass) {
    return unauthorized(res);
  };

  if (user.name === 'foo' && user.pass === 'bar') {
    return next();
  } else {
    return unauthorized(res);
  };
};

module.exports = app;

My router file index.js:

var express = require('express');
var router = express.Router();
router.get('/', auth, function(req, res) {
    res.render('index', { title: 'Express' });
});

module.exports = router;

Apparently the auth is not defined here. Can anybody tell me how can I use auth middleware function in my index.js router functions? Thanks

node.js
express
middleware

Answer 1

I'm not sure exactly what you're attempting to export with.

module.exports = app;

in app.js

Here is a simplifed solution:

index.js

var express = require('express');
var app = express();
var auth = require('./auth');

var router = express.Router();

router.use(auth);  // Auth middleware is first

router.get('/', function(req, res) {
  return res.send('Hello world');
}

// More routes can go here
// require('./external')(router);
// router.get('/route', function(req, res) {}

app.use(router);

app.listen(3000);

auth.js

module.exports = function(req, res, next) {
  return next();
}

If you have routes in other files you can either pass app or router

external.js

module.exports = function(router) {

}

Answer 2

Why not put your auth middleware in a separate file that you can require() and use from both app.js and your router files?