returning data to index.js node express

Question

Why is users undefined?

db.js:

 var MongoClient = require('mongodb').MongoClient var users; MongoClient.connect('mongodb://127.0.0.1:27017/ExpressApp2', function(err, db) { users = db.collection('usercollection'); users.find().each(function(err, doc) { console.log(doc); }); }); 

index.js

 var express = require('express'); var router = express.Router(); /* GET Userlist page. */ router.get('/userlist', function(req, res) { var users = require('../db').getUsers(); if (users==undefined) res.send('undefined'); else res.send('found something'); }); module.exports = router; 

The collection is correctly retrieved from Mongo and logged to screen, but users in index.js gives undefined.

Answer 1

In db.js you are not using module.exports to export your users.

Your code in index.js suggests db.js exports an object with a getUsers function but it does not.

Answer 2

MongoClient.connect('mongodb://127.0.0.1:27017/ExpressApp2', function(err, db)       {
    users = db.collection('usercollection');
    users.find().each(function(err, doc) {
        console.log(doc);
    });
});

should be

module.exports.getUsers = function() {
    MongoClient.connect('mongodb://127.0.0.1:27017/ExpressApp2', function(err, db)       {
        return db.collection('usercollection');
    });
}

I'm presuming that

users.find().each(function(err, doc) {
    console.log(doc);
});

is part of your debugging and what you actually want to return is the user collection. The important bit is adding the block to module.exports as getUsers().

Answer 3

I got it to work with this async call in the end. index.js

router.get('/userlist', function(req, res) {
var d = require('../db');
d.getUsers('input', function(users) {
    users.each(function(err, doc) {
        res.send(doc);
        return false;
    });

});

});