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# Ruby on Rails 2.1.x - Introduction

# Pre-Requisite :

Before you start Ruby on Rails please make sure you have basic understanding on the following subjects:

- Basic Ruby syntax and language constructs such as blocks.

- Basic understanding of relational databases and SQL.

- Basic understanding of HTML documents and CSS.

# What is Rails ?

- An extremely productive web-application framework.

- Written in Ruby by David Heinemeier Hansson.

- You could develop a web application at least ten times faster with Rails than you could with a typical Java framework.

- An open source Ruby framework for developing database-backed web applications.

- Your code and database schema are the configuration!

- No compilation phase required.

There are a few other reasons behind Rails' success:

## Full Stack Framework

- Includes everything needed to create a database-driven web application using the Model-View-Controller (MVC) pattern.

- Being a full-stack framework means that all layers are built to work seamlessly together Less Code.

- Requires fewer total lines of code than other frameworks spend setting up their XML configuration files.

## Convention over Configuration

- Rails shuns configuration files in favor of conventions, reflection and dynamic run-time extensions. Your application code and your running database already contain everything that Rails needs to know!

## Don't repeat yourself (DRY)

- DRY is a slogan you will hear frequently associated with Ruby on Rails which means you need to code behavior only once and you never have to write similar code in two different places. This is important because you are less likely to make mistakes by modifying your code at one place only.

# Rails Major Strengths:

Rails is packed with features that make you more productive, with many of the following features building on one other.

Metaprogramming : Other frameworks use extensive code generation from scratch. Metaprogramming techniques use programs to write programs. Ruby is one of the best languages for metaprogramming, and Rails uses this capability well. Rails also uses code generation but relies much more on metaprogramming for the heavy lifting.

Active Record : Rails introduces the Active Record framework, which saves objects to the database. The Rails version of Active Record discovers the columns in a database schema and automatically attaches them to your domain objects using metaprogramming.

Convention over configuration: Most web development frameworks for .NET or Java force you to write pages of configuration code. If you follow suggested naming conventions, Rails doesn't need much configuration.

Scaffolding: You often create temporary code in the early stages of development to help get an application up quickly and see how major components work together. Rails automatically creates much of the scaffolding you'll need.

Ajax at the core: Ajax is the technology that has become a standard to provide interactivity to websites without becoming intrusive. Ruby on Rails has a great support for Ajax technology and it is part of the core libraries. So when you install RoR, Ajax support is also made available to you.

Built-in testing: Rails creates simple automated tests you can then extend. Rails also provides supporting code called harnesses and fixtures that make test cases easier to write and run. Ruby can then execute all your automated tests with the rake utility.

Three environments: Rails gives you three default environments: development, testing, and production. Each behaves slightly differently, making your entire software development cycle easier. For example, Rails creates a fresh copy of the Test database for each test run.

# What is Rails 2.1.0 ?

This is the latest version of Ruby on Rails which has been released by the Rails core team on Saturday May 31, 2008.

This version is a further improvement on RoR 2.0 which was again really a fantastic release, absolutely stuffed with great new features, loads of fixes, and an incredible amount of polish over previous versions RoR 1.2.x.

This tutorial will take you through all the important features available in latest RoR version 2.1.0.

After this tutorial you should be able to build your website using one of the best Web 2.0 technologies called Ruby on Rails v2.1.0.

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