Basic Node / Express API

adminController.js

var adminRouter = require('../config/routers')().adminRouter;
var Book = require('../data/models/bookModel');
var db = require('../data/db')();

var adminController = function() {
    var books = [
        {
            title: 'War and Peace',
            author: 'Lev Nikolayevich Tolstoy',
            genre: 'Historical Fiction',
            read: false
        },
        {
            title: 'The Time Machine',
            author: 'H. G. Wells',
            genre: 'Science Fiction',
            read: false
        },
        {
            title: 'The Dark World',
            author: 'Henry Kuttner',
            genre: 'Fantasy',
            read: false
        }
    ];

    adminRouter.route('/book/add')
        .post(function(req, res) {
            var book = new Book(req.body);
            
            db.addBook(book, function(err, book) {
                if (err) {
                    res.send(err);
                }

                res.json(book);
            });
        });

    return adminRouter;
};

module.exports = adminController;

app.js

var express = require('express');
var middleware = require('./config/middleware');

var app = express();
var port = process.env.port || 3000;

middleware(app);

app.listen(port, function (err) {
    if (!err) {
        console.log('Running on port ' + port);
    } else {
        console.error(err);
    }
});

bookController.js

var bookRouter = require('../config/routers')().bookRouter;
var Book = require('../data/models/bookModel');
var db = require('../data/db')();

var bookController = function() {
    var throwError = function(err, req, res) {
        if (err) {
            res.send(err);
        }
    };

    bookRouter.route('/books')
        .get(function(req, res) {
            var query = {};
            
            if (req.query.genre) {
                query.genre = req.query.genre;
            }

            db.getBooks(query, function(err, books) {
                throwError(err, req, res);
                res.json(books);
            });
        });

    bookRouter.route('/book/:id')
        .get(function(req, res) {
            var id = req.params.id;

            db.getBookById(id, function(err, book) {
                throwError(err, req, res);
                res.json(book);
            });
        });

    return bookRouter;
};

module.exports = bookController;

bookModel.js

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var bookModel = new Schema({
    title: {
        type: String
    },
    author: {
        type: String
    },
    genre: {
        type: String
    },
    read: {
        type: Boolean,
        default: false
    }
});

module.exports = mongoose.model('Book', bookModel);

db.js

var mongoose = require('mongoose');
var bookModel = require('./models/bookModel');

var db = function() {
    var dbUrl = 'mongodb://localhost:27017/bookAPI';
    var Book = bookModel;

    var addBook = function(book, response) {
        if (typeof(book) !== 'object') {
            response('Not a valid book!', null);
        } else {
            mongoose.connect(dbUrl);

            book.save(function(err, book) {
                response(err, book);
                mongoose.disconnect();
            });
        }
    };

    var getBooks = function(query, response) {
        query = query || {};
        mongoose.connect(dbUrl);

        Book.find(query, function(err, books) {
            response(err, books);
            mongoose.disconnect();
        });
    };

    var getBookById = function(id, response) {
        mongoose.connect(dbUrl);

        Book.findById(id, function(err, book) {
            response(err, book);
            mongoose.disconnect();
        });
    };

    return {
        addBook: addBook,
        getBooks: getBooks,
        getBookById: getBookById
    };
};

module.exports = db;

homeController.js

var homeRouter = require('../config/routers')().homeRouter;

var bookController = function() {
    homeRouter.route('/')
        .get(function (req, res) {
            res.send('Welcome to my API!');
        });

    return homeRouter;
};

module.exports = bookController;

middleware.js

var adminController = require('../controllers/adminController')();
var bodyParser = require('body-parser');
var bookController = require('../controllers/bookController')();
var homeController = require('../controllers/homeController')();

var middleware = function(app) {
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({ extended: false }));
    
    app.use('/', homeController);
    app.use('/admin', adminController);
    app.use('/api', bookController);
};

module.exports = middleware;

routers.js

var express = require('express');

var routers = function() {
    var adminRouter = express.Router();
    var bookRouter = express.Router();
    var homeRouter = express.Router();

    return {
        adminRouter: adminRouter,
        bookRouter: bookRouter,
        homeRouter: homeRouter
    };
};

module.exports = routers;