CODEWITHSUNDEEP
javascriptnode.js
xillo
xillo

Reputation: 11

Node.js: making db variable available in controller files

I am fairly new to node.js.

I am currently using lowdb for my database while I get the app started.

In the index.js file I have:

var express = require('express');
var app = express();
var bodyParser = require('body-parser');
var request = require('request');
var path = require('path');
var low = require('lowdb');
var db = low('db.json');
var routes = require('./routes');

app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'));

app.use(express.static(path.join(__dirname, '/public')));
app.use('/', routes);

server.listen(3000, function(){
    console.log('listening on port 3000');
});

Then in my routes file I have something like:

var express = require('express');
var router = express.Router();
var account = require('./controllers/accounts.js');

router.post('/login', account.login);

router.get('/', function(req, res){
    res.render('home');
});

module.exports = router;

And finally in my account controller I have:

exports.login = function(req, res){
    var email = req.body.email;
    var password = req.body.password;
       ...
}

The routing to controller system works. However I need to access the lowdb object from all of my routed controller functions (and also possibly elsewhere).

If in app.js I set:

global.db = db;

Then it seems to work, but from what I have read, setting this globally isn't the ideal solution. What is the appropriate way to be able to access the db from the controller files without having to set the db connection in every single file.

Upvotes: 1

Views: 2036

Answers (2)

bkbooth
bkbooth

Reputation: 498

It looks like you can probably just setup and use the db directly in your routes file since you're not actually using the db in your main file. If it's that simple then I'd opt for doing that:

// routes file
var low = require('lowdb');
var db = low('db.json');

Alternatively, if you need to setup your db in the main file and pass it into the routes file and/or other modules, instead of exporting the router directly in the routes file, export a function which takes the db as input and returns the router. Then you can pass the db into the routes module when you require it.

// routes file
module.exports = function (db) {
  // router setup using the input `db`
  // ...
  return router;
}

// index.js
var low = require('lowdb');
var db = low('db.json');
var routes = require('./routes')(db);

Upvotes: 1

Bertrand Martel
Bertrand Martel

Reputation: 45432

In your index.js file (application root) store the lowdb object in your express object : 

var app = express();
var db = low('db.json');
app.db = db;

In your controller (accounts.js), access your database with req.app.db : 

exports.login = function(req, res){
    var email = req.body.email;
    var password = req.body.password;
    var db = req.app.db;
}

Upvotes: 2

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