Tag Archives: MongoDB

Node.js: Learn from the guy who wrote the book—actually, 14 of them!

Introduction to Node.js

If you’re a software developer with a few years of experience, and you’re new to Node.js or web development, join popular instructor Benjamin Lin and author and founder of Node University Azat Mardan for Introduction to Node.js, now available on edX. In just a few hours (and using the latest materials), make the leap from desktop apps, and see how easy and fast it is to get started on Node.js. Plus, who better to learn from than the always-entertaining Benjamin and his colleague Azat, who has written more than a dozen books on Node.js?

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Full Stack JavaScript

My new book Full Stack JavaScript (my 4th traditionally-published book) comes with a series of screencast videos for better immersion in a wonderful and mesmerizing world of Node.js, Backbone and MongoDB. It’s a one thing to read through the text and another to follow up with dynamic videos which walk you through the book’s projects.

Full Stack JavaScript

Full Stack JavaScript

The videos and the source code are open source, meaning they are publicly available. Therefore, you don’t have to buy a book—you can just watch the 14 videos on YouTube (playlist) and go through the code on GitHub (repository).

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MongoUI: Real-Time MongoDB Admin Web Interface (a la phpMyAdmin in Node.js)

MongoUI: Real-Time MongoDB Admin Web Interface is Your Life Ring

MongoUI is a real-time web interface for Node.js and MongoDB written with DerbyJS—a real-time full-stack web framework. It’s a app that can be run locally and on the server. Similarly, you can view and manipulate data in a local or remote database. The MongoUI project is in beta so use caution, and please contribute your feedback.

MongoUI on NPM: https://www.npmjs.org/package/mongoui

MongoUI on GitHub: https://github.com/azat-co/mongoui

MongoUI description (this page): http://webapplog.com/mongoui

MongoUI features include:

  • Switch databases and collections
  • Search by field value (string, number, ObjectId)
  • Save search / filter results as a bookmark (each URL has a query)
  • Edit any fields’ values in a real-time editor
  • Get raw JSON objects

Here’s a one-and-a-half-minute video that shows filtering, editing, and switching collections:

Direct link to the YouTube video: http://youtu.be/l8Rfpow0f9A.

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The Release of Express.js Guide: The Comprehensive Book on Express.js

Express.js is a de facto standard of Node.js development and the most popular NPM library as of today! However, as with any framework, sometimes the learning curve is steep. At HackReactor, I often asked the same questions about code organization, authentication, database connections and deployment.

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Todo App with Express.js/Node.js and MongoDB

Note: This tutorial is a part of Express.js Guide: The Comprehensive Book on Express.js.

Todo apps are considered to be quintessential in showcasing frameworks akin to famous Todomvc.com for front-end JavaScript frameworks. In this example, we’ll use Jade, forms, LESS, AJAX/XHR and CSRF.

In our Todo app, we’ll intentionally not use Backbone.js or Angular to demonstrate how to build traditional websites with the use of forms and redirects. In addition to that, we’ll explain how to plug-in CSRF and LESS.

Example: All the source code is in the github.com/azat-co/todo-express for your convenience.

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Tutorial: Node.js and MongoDB JSON REST API server with Mongoskin and Express.js

Update3: Expess 4 version of this tutorial is available at Express.js 4, Node.js and MongoDB REST API Tutorial, and github.com/azat-co/rest-api-express (master branch). This tutorial will work with Express 3.x.

Update2: “Mongoskin removed ‘db.collection.id’ and added some actionById methods” from this pull request with this code changes. To use the code in this post, just install an older version of Mongoskin (0.5.0?). The code in the GitHub will work with Mongoskin 1.3.20.

Update2: “Mongoskin removed ‘db.collection.id’ and added some actionById methods” from this pull request with this code changes. To use the code in this post, just install an older version of Mongoskin (0.5.0?)

Update: use the enhanced code from this repository github.com/azat-co/rest-api-express (express3 branch).

Note: This text is a part of Express.js Guide: The Comprehensive Book on Express.js.

This tutorial will walk you through writing test using the Mocha and Super Agent libraries and then use them in a test-driven development manner to build a Node.js free JSON REST API server utilizing Express.js framework and Mongoskin library for MongoDB. In this REST API server, we’ll perform create, read, update and delete (CRUD) operations and harness Express.js middleware concept with app.param() and app.use() methods.

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Rapid Prototyping with JS: Agile JavaScript Development is done with v0.5 (1.0RC)!

Rapid Prototyping with JS: Agile JavaScript Development

Rapid Prototyping with JS: Agile JavaScript Development

This is a release candidate for 1.0 version which is going to be available to public in print. Page count has increase from 151 to 211 pages (PDF), which include the following updates:

  • More digestible (smaller) code examples with better comments
  • Express.js middleware section with an example
  • Express.js + MongoDB REST API server section with an example
  • Derby section with an example
  • Grammar and typo fixes
  • Illustrations
  • Summaries in the beginning of each chapter
  • Code examples formatting fixes

Download a free chapter Intro to Backbone.js or full PDF, ePub or Mobi copy at LeanPub.

Rapid Prototyping with JS touched topics such as:

  • jQuery
  • AJAX
  • CSS and LESS
  • JSON and BSON
  • Twitter Bootstrap
  • Node.js
  • MongoDB
  • Parse.com
  • Agile methodologies
  • Git
  • Heroku, MongoHQ and Windows Azure
  • REST API
  • Backbone.js
  • AMD and Require.js
  • Express.js
  • Monk
  • Derby

If you need in-depth knowledge or references, they are usually one click or one Google search away.

Practical aspect included building multiple versions of the Message Board app:

  • jQuery + Parse.com JS REST API
  • Backbone and Parse.com JS SDK
  • Backbone and Node.js
  • Backbone and Node.js + MongoDB

The Message Board application has all the foundation of a typical web/mobile application: fetching data, displaying it, submitting new data. Other examples include:

  • jQuery + Twitter RESP API “Tweet Analyzer”
  • Parse.com “Save John”
  • Node.js “Hello World”
  • MongoDB “Print Collections”
  • Derby + Express “Hello World”
  • Backbone.js “Hello World”
  • Backbone.js “Apple Database”
  • Monk + Expres.js “REST API Server”

Oh My JS: The Best JavaScript Articles (https://leanpub.com/ohmyjs/) is in the works!

Nested Objects in Mongoose

There is a certain magic in ORMs like Mongoose. I learned it the hard way (as usual!), when I was trying to iterate over nested object’s properties. For example, here is a schema with a nested object features defines like this:

var User = module.exports = new Schema({
  features: { 
    realtime_updates: {
      type: Boolean
    },
    storylock: {
      type: Boolean
    },
    custom_embed_style: {
      type: Boolean
    },
    private_stories: {
      type: Boolean
    },
    headerless_embed:{
      type: Boolean
    }
};

Let’s say I want to overwrite object features_enabled with these properties:

if (this.features) { 
  for (var k in this.features) {
    features_enabled[k] = this.features[k];
  }
}
console.log(features_enabled)
return features_enabled;

Not so fast, I was getting a lot of system properties specific to Mongoose. Instead we need to use toObject(), e.g.:

if (this.features.toObject()) { 
  for (var k in this.features.toObject()) {
    console.log('!',k)
    features_enabled[k] = this.features.toObject()[k];
  }
}

Remember rule number one, computer is always right. If we think that it’s wrong — look up the rule number one. :-)

Intro to Express.js: Simple REST API app with Monk and MongoDB

Why?

After looking at Google Analytics stats I’ve realized that there is a demand for short Node.js tutorial and quick start guides. This is an introduction to probably the most popular (as of April 2013) Node.js framework Express.js.

Express.js — Node.js framework

Express.js — Node.js framework

mongoui

This app is a start of mongoui project. A phpMyAdmin counterpart for MongoDB written in Node.js. The goal is to provide a module with a nice web admin user interface. It will be something like Parse.com, Firebase.com, MongoHQ or MongoLab has but without trying it to any particular service. Why do we have to type db.users.findOne({'_id':ObjectId('...')}) any time we want to look up the user information? The alternative of MongoHub mac app is nice (and free) but clunky to use and not web based.

REST API app with Express.js and Monk

Ruby enthusiasts like to compare Express to Sinatra framework. It’s similarly flexible in the way how developers can build there apps. Application routes are set up in a similar manner, i.e., app.get('/products/:id', showProduct);. Currently Express.js is at version number 3.1. In addition to Express we’ll use Monk module.

We’ll use Node Package Manager which is usually come with a Node.js installation. If you don’t have it already you can get it at npmjs.org.

Create a new folder and NPM configuration file, package.json, in it with the following content:

{
  "name": "mongoui",
  "version": "0.0.1",
  "engines": {
    "node": ">= v0.6"
  },
  "dependencies": {
    "mongodb":"1.2.14",
    "monk": "0.7.1",
    "express": "3.1.0"
  }
}

Now run npm install to download and install modules into node_module folder. If everything went okay you’ll see bunch of folders in node_modules folders. All the code for our application will be in one file, index.js, to keep it simple stupid:

var mongo = require('mongodb');
var express = require('express');
var monk = require('monk');
var db =  monk('localhost:27017/test');
var app = new express();

app.use(express.static(__dirname + '/public'));
app.get('/',function(req,res){
  db.driver.admin.listDatabases(function(e,dbs){
      res.json(dbs);
  });
});
app.get('/collections',function(req,res){
  db.driver.collectionNames(function(e,names){
    res.json(names);
  })
});
app.get('/collections/:name',function(req,res){
  var collection = db.get(req.params.name);
  collection.find({},{limit:20},function(e,docs){
    res.json(docs);
  })
});
app.listen(3000)

Let break down the code piece by piece. Module declaration:

var mongo = require('mongodb');
var express = require('express');
var monk = require('monk');

Database and Express application instantiation:

var db =  monk('localhost:27017/test');
var app = new express();

Tell Express application to load and server static files (if there any) from public folder:

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

Home page, a.k.a. root route, set up:

app.get('/',function(req,res){
  db.driver.admin.listDatabases(function(e,dbs){
      res.json(dbs);
  });
});

get() function just takes two parameters: string and function. The string can have slashes and colons, for example product/:id. The function must have two parapemets request and response. Request has all the information like query string parameters, session, headers and response is an object to with we output the results. In this case we do it by calling res.json() function. db.driver.admin.listDatabases() as you might guess give us a list of databases in async manner.

Two other routes are set up in a similar manner with get() function:

app.get('/collections',function(req,res){
  db.driver.collectionNames(function(e,names){
    res.json(names);
  })
});
app.get('/collections/:name',function(req,res){
  var collection = db.get(req.params.name);
  collection.find({},{limit:20},function(e,docs){
    res.json(docs);
  })
});

Express conveniently supports other HTTP verbs like post and update. In the case of setting up a post route we write this:

app.post('product/:id',function(req,res) {...});

Express also has support for middeware. Middleware is just a request function handler with three parameters: request, response, and next. For example:

app.post('product/:id', authenticateUser, validateProduct, addProduct);

function authenticateUser(req,res, next) {
  //check req.session for authentication
  next();
}

function validateProduct (req, res, next) {
   //validate submitted data
   next();
}

function addProduct (req, res) {
  //save data to database
}

validateProduct and authenticateProduct are middleware. They are usually put into separate file (or files) in a big projects.

Another way to set up middle ware in Express application is to use use() function. For example earlier we did this for static assets:

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

We can also do it for error handlers:

app.use(errorHandler);

Assuming you have mongoDB installed this app will connect to it (localhost:27017) and display collection name and items in collections. To start mongo server:

$ mongod

to run app (keep the mongod terminal window open):

$ node .

or

$ node index.js

To see the app working, open http://localhost:3000 in Chrome with JSONViewer extension (to render JSON nicely).

Tom Hanks' The Polar Express

Tom Hanks’ The Polar Express