Include a module for all routes at express.js 4

Question

I'm using Express 4.2.0

Is it possible to include a module only once in app.js and use it in any defined route?

Right now this won't work:

app.js

//..
var request = require('request');

var routes = require('./routes/index');
var users = require('./routes/users');

app.use('/', routes);
app.use('/users', users);
//...

routes/user.js

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

router.get('/add', function(req, res) {
    var session = req.session;
    request('http://localhost:8181/Test?val1=getDepartments', function (error, response, body) {
       //...
    });

    res.render('users/add');
});

module.exports = router;

It will say that "request" is not defined in routes/user.js

ReferenceError: request is not defined at Object.module.exports [as handle] (C:\inetpub\wwwroot\node7\routes\users. js:12:5)

Having to include modules in every route which wants to use them doesn't sound like a proper solution...

Why shouldn't this be a proper solution? It means only to use dependencies that you really need. — saintedlama, Sep 19 '14 at 17:38

score 4 · Accepted Answer · answered Sep 19 '14 at 16:15

4

Yes, there are two ways of creating global variables in Node.js, one using the global object, and the other using module.exports

Here is how,

Method 1. Declare variable without var keyword. Just like importModName = require('modxyz') and it will be stored in global object so you can use it anywhere like global.importModName

Method 2. Using exports option. var importModName = require('modxyz'); module.exports = importModName ; and you can use it in other modules.

Look here for somemore explanation http://www.hacksparrow.com/global-variables-in-node-js.html

answered Sep 19 '14 at 16:15

user3366706

1,529
3
31
54

1

FWIW using `global`, especially like that, is generally frowned upon and can easily end up causing issues. – mscdex Sep 19 '14 at 16:18
1

Global objects can be used for small projects. As you said, It has to be barely used in large projects. – user3366706 Sep 19 '14 at 16:24
Should I duplicate the `app.use()` referencing those included files as well? ie: `var bodyParser = require('body-parser'); app.use( bodyParser.json() );` – Alvaro Sep 22 '14 at 09:43
Could you answer the my last comment please? – Alvaro Sep 25 '14 at 16:32
You dont need to duplicate app.use . Just importing required modules should work. – user3366706 Sep 25 '14 at 16:40

score 1 · Answer 2 · answered Sep 19 '14 at 16:11

1

You can leave out the var and do just request = require('request'); but this is frowned upon.

Node.js caches modules. The standard approach is to require modules where needed.

answered Sep 19 '14 at 16:11

Jordonias

5,778
2
21
32

Include a module for all routes at express.js 4

2 Answers2

Linked