MEAN Web Development

Most web applications are built in a three-tier architecture that consists of three important layers: data, logic, and presentation. In web applications, the application structure usually breaks down to database, server, and client, while in modern web development, it can also be broken into database, server logic, client logic, and client UI.

A popular paradigm of implementing this model is the MVC architectural pattern. In the MVC paradigm, the logic, data, and visualization are separated into three types of objects, each handling its own tasks. The View handles the visual part, taking care of user interaction. The Controller responds to system and user events, commanding the Model and View to change appropriately. The Model handles data manipulation, responding to requests for information or changing its state according to the Controller's instructions. A simple visual representation of MVC is shown in the following diagram:

Common MVC architecture communication

In the 25 years of web development, many technology stacks became popular building three-tier web applications; among those now ubiquitous stacks, you can find the LAMP stack, the .NET stack, and a rich variety of other frameworks and tools. The main problem with these stacks is that each tier demands a knowledge base that usually exceeds the abilities of a single developer, making teams bigger than they should be, less productive, and exposed to unexpected risks.

JavaScript is an interpreted computer programming language that was built for the Web. First implemented by the Netscape Navigator web browser, it became the programming language that web browsers use to execute client-side logic. In the mid 2000s, the shift from websites to web applications, along with the release of faster browsers, gradually created a community of JavaScript developers writing more complex applications. These developers started creating libraries and tools that shortened development cycles, giving birth to a new generation of even more advanced web applications, which in turn created a continuous demand for better browsers. This cycle went on for a few years, where the vendors kept improving their browsers and JavaScript developers kept pushing the boundaries. The real revolution began in 2008, when Google released its Chrome browser, along with its fast JIT-compiling V8 JavaScript engine. Google's V8 engine made JavaScript run so much faster that it completely transformed web application development. More importantly, the release of the engine's source code allowed developers to start reimagining JavaScript outside of the browser. One of the first products of this revolution was Node.js.

After looking into other options for a while, programmer Ryan Dahl found that V8 engine fit his non-blocking I/O experiment called Node.js. The idea was simple: help developers build non-blocking units of code to allow better use of system resources and create more responsive applications. The result was a minimal yet powerful platform, which utilized JavaScript's non-blocking nature outside of the browser. Node's elegant module system enabled developers to freely extend the platform using third-party modules to achieve almost any functionality. The reaction by the online community was a creation of various tools from modern web frameworks to robotics server platforms. However, server-side JavaScript was only the beginning.

When Dwight Merriman and Eliot Horowitz set out to build their scalable hosting solution back in 2007, they already had a lot of experience with building web applications. However, the platform they built did not succeed as planned, so in 2009 they decided to take it apart and open source its components, including a V8-based database called MongoDB. Derived from the word humongous, MongoDB was a scalable NoSQL database that used a JSON-like data model with dynamic schemas. MongoDB gained a lot of traction right away by giving developers the flexibility they needed when dealing with complex data, while providing RDBMS features such as advanced queries and easy scaling—features that eventually made MongoDB one of the leading NoSQL solutions. JavaScript broke another boundary. But the JavaScript revolutionaries haven't forgotten where it all began; in fact, the popularization of modern browsers created a new wave of JavaScript frontend frameworks.

Back in 2009, while building their JSON as a platform service, developers Miško Hevery and Adam Abrons noticed that the common JavaScript libraries weren't enough. The nature of their rich web application raised the need for a more structured framework that would reduce grunt work and maintain an organized code base. Abandoning the original idea, they decided to focus on the development of their frontend framework and open sourced the project, naming it AngularJS. The idea was to bridge the gap between JavaScript and HTML and help popularize single page application development. The result was a rich web framework, which presented frontend web developers with concepts such as two-way data binding, cross-component dependency injection, and MVC-based components. AngularJS along with other MVC frameworks revolutionized web development by transforming the once unmaintainable frontend code base into a structured code base that can support more advanced development paradigms such as TDD.

The rise of open source collaboration tools, along with the devoted involvement of these talented engineers, created one of the richest communities in the world. More importantly, these major advancements allowed the development of three-tier web applications to be unified under JavaScript as the programming language across all three layers—an idea that is commonly referred to as the full-stack JavaScript. The MEAN stack is just a single example of this idea.

MEAN is an abbreviation for MongoDB, Express, AngularJS, and Node.js. The concept behind it is to use only JavaScript - driven solutions to cover the different parts of your application. The advantages are great and are as follows:

However, there are still a few important questions that remain unanswered:

In this book, I'll try to answer these questions and many more, but before we can go any further, you will first need to install the basic prerequisites.

For MongoDB's stable versions, the official MongoDB website supplies linked binaries that provide the easiest way to install MongoDB on Linux, Mac OS X, and Windows. Notice that you need to download the right architecture version for your operating system. If you use Windows or Linux, make sure to download either the 32-bit or 64-bit version according to your system architecture. Mac users are safe to download the 64-bit version.

When you visit the download page at http://mongodb.org/downloads, you'll be offered a download of an archive containing the binaries you need to install MongoDB. After downloading and extracting the archive file, you will need to locate the mongod binary, which is usually located in the bin folder. The mongod process runs the main MongoDB server process, which can be used as a standalone server or a single node of a MongoDB replica set. In our case, we will use MongoDB as a standalone server. The mongod process requires a folder to store the database files in (the default folder is /data/db) and a port to listen to (the default port is 27017). In the following subsections, we'll go over the setup steps for each operating system; we'll begin with the common Windows installation process.

Installing MongoDB on Windows

Once you have downloaded the right version, unpack the archive file, and move the folder to C:\mongodb. MongoDB uses a default folder to store its files. On Windows, the default location is C:\data\db, so in the command prompt, go to C:\ and issue the following command:

> md data\db

Note

You can tell the mongod service to use an alternative path for the data files using the --dbpath command-line flag.

Once you've moved the MongoDB files to the right folder and finished creating the data folders, you'll get two options while running the main MongoDB service.

Running MongoDB manually

To run MongoDB manually, you will need to run the mongod binary. So, open the command prompt and issue the following command:

> C:\mongodb\bin\mongod.exe

The preceding command will run the main MongoDB service that starts listening to the default 27017 port. If everything goes well, you should see a console output similar to the following screenshot.

Running the MongoDB server on Windows

Depending on the Windows security level, a security alert dialog, which notifies you about the blocking of some service features, will be issued. If this occurs, select a private network and click on Allow Access.

Note

You should be aware that the MongoDB service is self-contained, so you can alternatively run it from any folder of your choice.

Running MongoDB as a Windows Service

The more popular approach is running MongoDB automatically after every reboot cycle. Before you begin setting up MongoDB as a Windows Service, it's considered good practice to specify a path for the MongoDB log and configuration files. Start by creating a folder for these files by running the following command in your command prompt:

> md C:\mongodb\log

Then, you'll be able to create a configuration file using the --logpath command-line flag, so in the command prompt, issue the following command:

> echo logpath=C:\mongodb\log\mongo.log > C:\mongodb\mongod.cfg

When you have your configuration file in place, open a new command prompt window with administrative privileges by right-clicking on the command prompt icon and clicking on Run as administrator. In the new command prompt window, install the MongoDB service by running the following command:

> sc.exe create MongoDB binPath= "\"C:\mongodb\bin\mongod.exe\" --service --config=\"C:\mongodb\mongod.cfg\"" DisplayName= "MongoDB 2.6" start= "auto"

If the service was successfully created, you will get the following log message:

[SC] CreateService SUCCESS

Notice that the install process will only succeed if your configuration file is set correctly and contains the logpath option. After installing your MongoDB service, you can run it by executing the following command in the administrative command prompt window:

> net start MongoDB

Note

Downloading the example code

You can download the example code files for all the Packt books you have purchased from your account at http://www.packtpub.com. If you purchased this book elsewhere, you can visit http://www.packtpub.com/support and register to have the files e-mailed to you.

Be aware that the MongoDB configuration file can be modified to accommodate your needs. You can learn more about it by visiting http://docs.mongodb.org/manual/reference/configuration-options/.

Installing MongoDB on Mac OS X and Linux

In this section, you'll learn the different ways of installing MongoDB on Unix-based operating systems. Let's begin with the simplest way to install MongoDB, which involves downloading MongoDB's precompiled binaries.

Installing MongoDB from binaries

You can download the right version of MongoDB using the download page at http://www.mongodb.org/downloads. Alternatively, you can do this via CURL by executing the following command:

$ curl -O http://downloads.mongodb.org/osx/mongodb-osx-x86_64-2.6.4.tgz

Notice that we have downloaded the Mac OS X 64-bit version, so make sure you alter the command to fit the version suitable for your machine. After the downloading process is over, unpack the file by issuing the following command in your command-line tool:

$ tar -zxvf mongodb-osx-x86_64-2.6.4.tgz

Now, change the name of the extracted folder to a simpler folder name by running the following command:

$ mv mongodb-osx-x86_64-2.6.4 mongodb

MongoDB uses a default folder to store its files. On Linux and Mac OS X, the default location is /data/db, so in your command-line tool run the following command:

$ mkdir -p /data/db

Note

You may experience some troubles creating this folder. This is usually a permission issue, so use sudo or super user when running the preceding command.

The preceding command will create the data and db folders because the –p flag creates parent folders as well. Notice that the default folder is located outside of your home folder, so do make sure you set the folder permission by running the following command:

$ chown -R $USER /data/db

Now that you have everything prepared, use your command-line tool and go to the bin folder to run the mongod service as follows:

$ cd mongodb/bin
$ mongod

This will run the main MongoDB service, which will start listening to the default 27017 port. If everything goes well, you should see a console output similar to the following screenshot:

Running the MongoDB server on Mac OS X

Install MongoDB using a package manager

Sometimes the easiest way to install MongoDB is by using a package manager. The downside is that some package managers are falling behind in supporting the latest version. Luckily, the team behind MongoDB also maintains the official packages for RedHat, Debian, and Ubuntu, as well as a Hombrew package for Mac OS X. Note that you'll have to configure your package manager repository to include the MongoDB servers to download the official packages.

To install MongoDB on Red Hat Enterprise, CentOS, or Fedora using Yum, follow the instructions at http://docs.mongodb.org/manual/tutorial/install-mongodb-on-red-hat-centos-or-fedora-linux/.

To install MongoDB on Ubuntu using APT, follow the instructions at http://docs.mongodb.org/manual/tutorial/install-mongodb-on-ubuntu/.

To install MongoDB on Debian using APT, follow the instructions at http://docs.mongodb.org/manual/tutorial/install-mongodb-on-debian/.

To install MongoDB on Mac OS X using Homebrew, follow the instructions at http://docs.mongodb.org/manual/tutorial/install-mongodb-on-os-x/.

Using the MongoDB shell

MongoDB archive file includes the MongoDB shell, which allows to you to interact with your server instance using the command line. To start the shell, navigate to the MongoDB bin folder and run the mongo service as follows:

$ cd mongodb/bin
$ mongo

If you successfully installed MongoDB, the shell will automatically connect to your local instance, using the test database. You should see a console output similar to the following screenshot:

Running the MongoDB shell on Mac OS X

To test your database, run the following command:

> db.articles.insert({title: "Hello World"})

The preceding command will create a new article collection and insert a JSON object containing a title property. To retrieve the article object, execute the following command:

> db.articles.find()

The console will output the following message:

{ _id : ObjectId("52d02240e4b01d67d71ad577"), title: "Hello World " }

Congratulations! This means your MongoDB instance is working properly and you have successfully managed to interact with it using the MongoDB shell. In the upcoming chapters, you'll learn more about MongoDB and how to use the MongoDB shell.

For the stable versions, the official Node.js website supplies linked binaries that provide the easiest way to install Node.js on Linux, Mac OS X, and Windows. Note that you need to download the right architecture version for your operating system. If you use Windows or Linux, make sure to download either the 32-bit or 64-bit version according to your system architecture. Mac users are safe to download the 64-bit version.

Installing Node.js on Windows

Installing Node.js on a Windows machine is a simple task that can be easily accomplished using the standalone installer. To begin with, navigate to the http://nodejs.org/download/ page and download the right .msi file. Notice there are 32-bit and 64-bit versions, so make sure you download the right one for your system.

After downloading the installer, run it. If you get any security dialog boxes, just click on the Run button and the installation wizard should start. You will be prompted with an installation screen similar to the following screenshot:

Node.js Windows installation wizard

Once you click on the Next button, the installation should begin. A few moments later, you'll see a confirmation screen similar to the following screenshot, telling you Node.js was successfully installed:

Node.js Windows installation confirmation

Installing Node.js on Mac OS X

Installing Node.js on Mac OS X is a simple task that can be easily accomplished using the standalone installer. Start by navigating to the http://nodejs.org/download/ page and download the .pkg file.

After downloading the installer, run it and you will be prompted with an installation screen similar to the following screenshot:

Node.js Mac OS X Installation Wizard

Click on Continue and the installation process should begin. The installer will ask you to confirm the license agreement and then offer you to select the folder destination. Choose the option most suitable for you before clicking on the Continue button again. The installer will then ask you to confirm the installation information and ask you for your user password. A few moments later, you'll see a confirmation screen similar to the following screenshot, telling you that Node.js was successfully installed:

Node.js Mac OS X installation confirmation

$ tar -zxf node-v0.10.31.tar.gz
$ cd node-v0.10.31
$ ./configure && make && sudo make install

$ node

> console.log('Node is up and running!');
Node is up and running!
undefined

console.log('Node is up and running!');

$ node application.js
Node is up and running!

Node.js is a platform, which means its features and APIs are kept to a minimum. To achieve more complex functionality, it uses a module system that allows you to extend the platform. The best way to install, update, and remove Node.js modules is using the NPM. NPM has the following main features:

Conveniently, NPM is installed during the Node.js installation process, so let's quickly jump in and learn how to use it.

Using NPM

To understand how NPM works, we're going to install the Express web framework module, which you'll use in the upcoming chapters. NPM is a robust package manager, which keeps a centralized registry for public modules. To browse the available public packages, visit the official website at https://npmjs.org/.

Most of the packages in the registry are open source and contributed by the Node.js community developers. When developing an open source module, the package author can decide to publish it to the central registry, allowing other developers to download and use it in their projects. In the package configuration file, the author will choose a name that will later be used as a unique identifier to download that package.

Note

It is recommended you learn more about Node.js by visiting the official documentation at https://npmjs.org.

The installation process of NPM

It is important to remember that NPM has two installation modes: local and global. The default local mode is used more often and installs the third-party packages in a local node_modules folder placed inside your application folder. It has no effect system-wise, and is used to install the packages your application needs, without polluting your system with unnecessary global files.

The global mode is used to install packages you want Node.js to use globally. Usually these are CLI tools, such as Grunt, that you'll meet in the upcoming chapters. Most of the time, the package author will specifically instruct you to install the package globally. Therefore, whenever in doubt, use the local mode. The global mode will usually install the packages in the /usr/local/lib/node_modules folder for Unix-based systems and the C:\Users\%USERNAME%\AppData\Roaming\npm\node_modules folder for Windows-based systems, making it available to any Node.js application running on the system.

Installing a package using NPM

Once you find the right package, you'll be able to install it using the npm install command as follows:

$ npm install <Package Unique Name>

Installing a module globally is similar to its local counterpart, but you'll have to add the –g flag as follows:

$ npm install –g <Package Unique Name>

Note

You may find out that your user doesn't have the right permissions to install packages globally, so you'll have to use the root user or install it using sudo.

For example, to locally install Express, you'll need to navigate to your application folder and issue the following command:

$ npm install express

The preceding command will install the latest stable version of the Express package in your local node_modules folder. Furthermore, NPM supports a wide range of semantic versioning, so to install a specific version of a package, you can use the npm install command as follows:

$ npm install <Package Unique Name>@<Package Version>

For instance, to install the second major version of the Express package, you'll need to issue the following command:

$ npm install express@2.x 

This will install the latest stable version of Express 2. Note that this syntax enables NPM to download and install any minor version of Express 2. To learn more about the supported semantic versioning syntax, it is recommended that you visit https://github.com/isaacs/node-semver.

When a package has dependencies, NPM will automatically resolve those dependencies, installing the required packages in a node_modules folder inside the package folder. In the preceding example, the Express dependencies will be installed under node_modules/express/node_modules.

Removing a package using NPM

To remove an installed package, you'll have to navigate to your application folder and run the following command:

$ npm uninstall < Package Unique Name>

NPM will then look for the package and try to remove it from the local node_modules folder. To remove a global package, you'll need to use the -g flag as follows:

$ npm uninstall –g < Package Unique Name>

Updating a package using NPM

To update a package to its latest version, issue the following command:

$ npm update < Package Unique Name>

NPM will download and install the latest version of this package even if it doesn't exist yet. To update a global package, use the following command:

$ npm update –g < Package Unique Name>

Managing dependencies using the package.json file

Installing a single package is nice, but pretty soon, your application will need to use several packages, and so you'll need a better way to manage these package dependencies. For this purpose, NPM allows you to use a configuration file named package.json in the root folder of your application. In your package.json file, you'll be able to define various metadata properties of your application, including properties such as the name, version, and author of your application. This is also where you define your application dependencies.

The package.json file is basically a JSON file that contains the different attributes you'll need to describe your application properties.

An application using the latest Express and Grunt packages will have a package.json file as follows:

{
  "name" : "MEAN",
  "version" : "0.0.1",
  "dependencies" : {
    "express" : "latest",
    "grunt" : "latest"
  }
}

Note

Your application name and version properties are required, so removing these properties will prevent NPM from working properly.

Creating a package.json file

While you can manually create a package.json file, an easier approach would be to use the npm init command. To do so, use your command-line tool and issue the following command:

$ npm init

NPM will ask you a few questions about your application and will automatically create a new package.json file for you. A sample process should look similar to the following screenshot:

Using NPM init on Mac OS X

After creating your package.json file, you'll need to modify it and add a dependencies property. Your final package.json file should look like the following code snippet:

{
  "name": "MEAN",
  "version": "0.0.1",
  "description": "My First MEAN Application",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [
    "MongoDB",
    "Express",
    "AngularJS",
    "Node.js"
  ],
  "author": "Amos Haviv",
  "license": "MIT",
  "dependencies": {
    "express": "latest",
    "grunt": "latest"
  }
}

Note

In the preceding code example, we used the latest keyword to tell NPM to install the latest versions of these packages. However, it is highly recommended that you use specific version numbers or range to prevent your application dependencies from changing during development cycles. This is because new package versions might not be backward compatible with older versions, which will cause major issues in your application.

Installing the package.json dependencies

After creating your package.json file, you'll be able to install your application dependencies by navigating to your application's root folder and using the npm install command as follows:

$ npm install

NPM will automatically detect your package.json file and will install all your application dependencies, placing them under a local node_modules folder. An alternative and sometimes better approach to install your dependencies is to use the following npm update command:

$ npm update

This will install any missing packages and will update all of your existing dependencies to their specified version.

Updating the package.json file

Another robust feature of the npm install command is the ability to install a new package and save the package information as a dependency in your package.json file. This can be accomplished using the --save optional flag when installing a specific package. For example, to install the latest version of Express and save it as a dependency, you can issue the following command:

$ npm install express --save

NPM will install the latest version of Express and will add the express package as a dependency to your package.json file. For clarity reasons, in the upcoming chapters, we'll prefer to manually edit the package.json file; however, this useful feature can come in pretty handy in your daily development cycles.

Note

It is recommended that you learn more about NPM's vast configuration options by visiting the official documentation at https://npmjs.org/doc/json.html.

In this chapter, you learned how to install MongoDB and how to connect to your local database instance using the MongoDB shell. You also learned how to install Node.js and use the Node.js CLI. You learned about NPM and discovered how to use it to download and install Node.js packages. You also learned how to easily manage your application dependencies using the package.json file. In the next chapter, we'll discuss some Node.js basics and you'll build your first Node.js web application.