Ruby On Rails Introduction And Installation

What is Ruby on Rails?

• Ruby on Rails (or “Rails”) is an open source framework for building powerful web applications.
• Rails was created in 2004 by David Heinemeier Hansson (aka “DHH”)
• Rails is based on the “Ruby” language.
• Rails can work with multiple types of servers and databases.
• Rails is based on the MVC design pattern.
• Ruby on rails is NOT a language. It is a framework.
• Rails is extremely productive web-application framework.
• Rails can develop a web application at least ten times faster than you can compile a typical Java framework.

What is Different about Rails?

Ruby on Rails is in its own class and is different than other frameworks.

• Convention over configuration
  There are lots of development frameworks for java or .net frameworks; they are forced to write configuration codes in some pages. But Rails doesn't need much configuration.
  
  
• Meta programming
  Meta programming techniques are used to write programs. Ruby is one of the best language supports for Meta programming and Rails also uses this support as well for code generation.
  
  
• Active Record
  Rails introduces the Active Record framework service, which saves objects to the database. The Active Record shows data columns in a database and it automatically attaches to our domain using Meta programming.
  
  
• Built-in testing
  Rails creates automated tests. Rails also gives supporting code called enhancing and error fixtures that make it easier to write the code and execute the code.
  
  
• Independent of the web server
  
  
• Everything is an object

What is Ruby?

• Ruby is a programming language like java.
• Ruby is a pure object-oriented, interpreted, open source programming language created by a Japanese man Yukihiro “Matz” Matsumoto in 1993.
• It was released publicly in 1995.
• It was created for productivity as well as to have fun with. Created with the programmer in mind.
• Many developers say ruby is the most concise and expressive language available.
• Martz took the best part of all of his favorite languages and used them in Ruby.
• The Ruby is designed to be complete, simple, extensible and portable language.
• Developed mostly on Linux operating systems, Ruby works most of the platforms like UNIX, Windows, Mac, and DOS.
• Ruby’s simple syntax inspired by Ada and Eiffel so it make readable by anyone who is familiar with modern programming language.
• Ruby is similar to Smalltalk and Perl.
• Used for both desktop applications and web applications(rails)

You don’t need to be fluent in Ruby to learn Ruby on Rails. In fact, many people learn Rails and do not know a Ruby but you must understand programming.

Ruby is A Multi –Paradigm Language

• Ruby is an object oriented language but can use multiple paradigms for different problems
• Ruby is object oriented at its core but can also use functional and imperative paradigms.
• Ruby claims there is no one size fits all. Different problems or aspects of code sometimes need more than one programming paradigm.

Everything is an object

When working in Ruby, its is important to understand that it treats EVERYTHING as an object

• Numbers
• Strings
• Booleans
• Statements
• Methods/Functions

Objects can have methods

• “hello“.reverse
• “hello”.length

Syntax of Ruby

Ruby syntax is similar to Perl and Python

Keywords signal class and method definition

What is different?

• No brace is used for methods
• No needed semi-colon
• Uppercase variables are constants
• Ruby keeps all instance variable private to the class
• $ And @ are not thought of as data types but scope resolution.

RubyGems

• RubyGems is a package manager for the Ruby language.
• Used to distribute Ruby-based programs and libraries
• Used as a tool to manage installation of gems.
• RubyGems is part of the standard library from Ruby.
• Rails is actually a gem itself

code

Windows & Linux Systems

• Rails runs on both operating systems.
• Rails is very popular with Linux users.
• More and more people are Using Windows but dabble in Linux as well.
• Windows RailsInstaller package.
• Windows Interactive Ruby package.

How to install Ruby on Rails

Step 1