Promises with MongoDB

db_native_mongo.js

var Promise = require('bluebird');
var MongoClient = Promise.promisifyAll(require('mongodb').MongoClient);
var secret = require('./secret.js');

// url for connecting to the db
var url = secret.db_url;

module.exports = function activateMongo(){
    return MongoClient.connectAsync(url);
};

prezo.js

var SlideShare = require('slideshare'),
    segredo = require('./secret.js'),
    express = require('express'),
    bodyParser = require("body-parser"),
    fs = require('fs'),
    http = require('http'),
    https = require('https'),
    tag = process.argv[2] || 'angular';

var routes = require('./routes/route');

var ss = new SlideShare(segredo.key, segredo.secret);

function gatherSlides(){    
    ss.getSlideshowsByTag(tag, {limit: 10}, function(result){
        console.log(result.Tag.Slideshow[0]);
        
    });
}

var app = express();
var server = http.createServer(app);

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));

app.set('views', './views');
app.set('view engine', 'jade');

app.use(express.static(__dirname + '/client'));

app.use('/', routes);

server.listen(process.env.PORT || 3000, process.env.IP || '0.0.0.0', function(){
    var addr = server.address();
    console.log('Server listening at', addr.address + ':' + addr.port);
});

route.js

var router = require('express').Router();
var db = require('../db_native_mongo');
var Promise = require('bluebird');

router.route('/presentation')
.get(function getIndex(req, res){
    ss.getSlideshowsByTag(tag, {limit: 10}, function(result){
        var embed = result.Tag.Slideshow[0].Embed;
        res.render('index', {embed: embed});
        res.end();
    });
});

router.route('/quiz')
.get(function getQuiz(req, res){
    res.render('quiz', {questions: questions});
    res.end();
});

router.route('/ng-quiz')
.get(function getNgQuiz(req, res){
        res.render('ng-quiz');
        res.end();
});

router.route('/signup')
.get(function(req, res) {
    res.render('signup', {form:{}});
    res.end();
})
.post(function(req, res) {
    // check input
    
    // if good, save to db
    var b = req.body;
    var u = new User(b.user_name, b.pass_word, b.first_name, b.last_name);
    db().then(u.save).then(console.log)
    // redirect to success page
    .then(function(){
        res.render('thank-you')
    })
    // otherwise, send back to form with errors
    .catch(function(e){
        var err = e;
        res.render('signup', {form: req.body, message: err});
    });
});

function User(uname, password, firstName, lastName){
    if (notInstanceOf(this, User)){
        return new User(uname, password, firstName, lastName);
    }
    this.uname = uname;
    this.password = password;
    this.firstName = firstName;
    this.lastName = lastName;
}
User.prototype.save = function saveUserAsync(db){
    // Get users collection
    var collection = Promise.promisifyAll(db.collection('users'));
    return collection.insertAsync({
        userName: this.uname,
        password: this.password,
        firstName: this.firstName,
        lastName: this.lastName
    });
};

function assertType(obj, type) {
   var msg;
   if (obj === null) {
       msg = 'null';
   } else if (obj === undefined) {
       msg = 'undefined';
   } else if (notInstanceOf(obj, type)) {
       msg = obj.constructor.name;
   }
   if (msg) {
       throw new Error(msg + ' not instance of ' + type.name).stack;
   }
}

function notInstanceOf(obj, type) {
   return !instanceOf(obj, type);
}

function instanceOf(obj, type) {
   return (obj.constructor === type);
}

module.exports = router;

signup.jade

doctype html
html
    head
        title Sign Up
        link(rel="stylesheet", href="/css/main.css")
    body
        form(action="/signup", method="post")
            label(for="firstName") First Name 
                input#firstName(name="first_name", required, value="#{form.first_name || ''}")
            br
            label(for="lastName") Last Name 
                input#lastName(name="last_name", required)
            br
            label(for="username") Username 
                input#username(name="user_name", required)
            br
            label(for="password") Password 
                input#password(type="password", name="pass_word", required)
            .button
                button(type="submit") Send away!
            .error #{message}

thank-you.jade

doctype html
html
    head
        title Thank You
        link(rel="stylesheet", href="/css/main.css")
    body Thanks for signing up.