How To Code A Ruby on Rails Web Application

Ruby on Rails is a web application framework.

Rails is the framework, Ruby is the language.

Designed by David Heinemeier Hansson in 2005, it's become renowned in the Internet startup world for its adoption by some of the leading "startups" of our time, including Stripe, Uber and Groupon.

If you want to learn to program in Ruby on Rails, this tutorial should give you an overview of what to do. I won't go into specifics because I just want to give you an idea as to the structure of an application. If you follow what I propose, you should more fully understand how these applications work.

Web Applications

All software applications work in the same way -

·         Data is inputted

·         Data is processed

·         Data is outputted

The way the data is inputted and processed is dependent on the platform your application runs on. How it is outputted depends on your application.

The difference with web applications is that their logic runs on a server, with the data IO being passed through the Internet (specifically, the HTTP protocol).

The complication of web apps is that you require the ability to accept inbound data, and return responses. This is handled by a web server program (NGinx or Apache). I'll explain this in a minute.

Software Stack

When you create a piece of software, you have to consider the "stack" on which it runs.

The "stack" is all the software required to run your application. In the world of desktop games, for example, the "stack" may include the likes of DirectX or a particular graphics driver.

The main hold-back for would-be web application developers is understanding how the "web" software stack works. Web works similarly to native applications, except for one distinct difference - stateless.

The "Internet" operates under the HTTP protocol. By nature, this is known as a "stateless" protocol - each request you send is considered independent to the last. Unlike stateful protocols (which retain state), stateless protocols have to rebuild the application's state each time.

Whilst this means nothing to most people, the point is that if you're going to develop a web based application, you need to use a framework or technology set which makes the stateless nature of HTTP as integrated as possible. Most pertinently, you need an authentication system which rebuilds the user's session on every request (I'll explain this in a second).

Ruby vs PHP

Ruby (the language) is akin to PHP - they are both procedural and both are used heavily on the Internet.

The main difference between Ruby and PHP is that PHP is accessed directly on the client-side, Ruby needs a proxy.

Applications such as WordPress are built with PHP because it's free, open source and can be run on any LAMP (Linux Apache MySQL PHP) server (which is basically all of the shared hosting in existence).

The point with Ruby is that it is a LOT more temperamental than PHP - it requires running processes to help it operate and can often fail to start if any issues arise.

Basics

To get started, you need three things:

·         An IDE (Integrated Development Environment)

·         A Ruby-Compatible Web Server (Heroku)

·         Ruby, Rails & GIT Installed On Your System

I'll explain how it works.

An "IDE" is a text editor with the ability to discern the code you input. I currently use Atom (free) from Github. You can download it from Atom.io.

The IDE allows you to write the code. Whilst you're free to use a standard text editor (Notepad or Notepad++), it's much better to use a system such as Atom or even Visual Studio, as to gain the full functionality of the language (linting etc).

From here, you'll also need to install Ruby, Rails and GIT on your development system. Ruby is the programming language (nothing works unless you have it), Rails is the framework which allows us to build the web based application, and GIT is the SCM (Source Code Management) system we will use to push our code to our server.

For server technology, the easiest is to use Heroku (Heroku.com) - a completely managed system. You can get started for free, with upgraded capacity, speed etc added at extra monthly cost. If you're comfortable setting up your own server, you may wish to use the likes of DigitalOcean.