Ruby on Rails 2.1 About the Tutorial Ruby on Rails is an extremely productive web application framework written in Ruby by David Heinemeier Hansson. This tutorial gives you a complete understanding on Ruby on Rails 2.1. Audience This tutorial has been designed for beginners who would like to use the Ruby framework for developing database-backed web applications. Prerequisites Before you start Ruby on Rails, please make sure you have a basic understanding on the following subjects: Ruby syntax and language constructs such as blocks. Relational databases and SQL. HTML documents and CSS. Copyright & Disclaimer Copyright 2015 by Tutorials Point (I) Pvt. Ltd. All the content and graphics published in this e-book are the property of Tutorials Point (I) Pvt. Ltd. The user of this e-book is prohibited to reuse, retain, copy, distribute or republish any contents or a part of contents of this e-book in any manner without written consent of the publisher. 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Audience .................................................................................................................................................... i Prerequisites .............................................................................................................................................. i Copyright & Disclaimer .............................................................................................................................. i Table of Contents ...................................................................................................................................... ii 1. INTRODUCTION ..................................................................................................................... 1 What is Ruby? ........................................................................................................................................... 1 Why Ruby? ............................................................................................................................................... 1 Sample Ruby Code .................................................................................................................................... 2 Embedded Ruby ........................................................................................................................................ 2 What is Rails? ........................................................................................................................................... 3 Full Stack Framework ................................................................................................................................ 4 Convention over Configuration ................................................................................................................. 4 Don't Repeat Yourself (DRY) ..................................................................................................................... 4 Rails Strengths .......................................................................................................................................... 4 What is Rails 2.1.0? ................................................................................................................................... 5 2. INSTALLATION ....................................................................................................................... 6 Rails Installation on Windows ................................................................................................................... 6 Rails Installation on Mac OS X ................................................................................................................... 7 Rails Installation on Linux ......................................................................................................................... 7 Keeping Rails Up-to-Date .......................................................................................................................... 8 Installation Verification ............................................................................................................................ 8 How to Upgrade? ...................................................................................................................................... 9 ii Ruby on Rails 2.1 3. FRAMEWORK ...................................................................................................................... 10 Ruby on Rails MVC Framework ............................................................................................................... 10 Representation of MVC Framework ........................................................................................................ 11 Directory Representation of MVC Framework ........................................................................................ 12 4. DIR STRUCTURE .................................................................................................................. 13 5. EXAMPLES ........................................................................................................................... 16 Workflow for Creating Rails Applications ................................................................................................ 16 Creating an Empty Rails Application ....................................................................................................... 16 Starting Web Server ................................................................................................................................ 17 6. DATABASE SETUP ................................................................................................................ 19 Configuring database.yml ....................................................................................................................... 19 7. ACTIVE RECORDS ................................................................................................................ 21 Translating a Domain Model into SQL ..................................................................................................... 21 Creating Active Record Files .................................................................................................................... 21 Creating Associations between Models .................................................................................................. 22 Implementing Validations ....................................................................................................................... 23 8. MIGRATIONS ....................................................................................................................... 24 What can Rails Migration Do? ................................................................................................................. 24 Create the Migrations ............................................................................................................................. 25 Edit the Code to Tell it What to Do .......................................................................................................... 25 Run the Migration ................................................................................................................................... 27 Running Migrations for Production and Test Databases ......................................................................... 27 9. CONTROLLERS ..................................................................................................................... 28 iii Ruby on Rails 2.1 Implementing the list Method ................................................................................................................ 29 Implementing the show Method............................................................................................................. 29 Implementing the new Method .............................................................................................................. 30 Implementing the create Method ........................................................................................................... 30 Implementing the edit Method ............................................................................................................... 31 Implementing the update Method .......................................................................................................... 31 Implementing the delete Method ........................................................................................................... 31 Additional Methods to Display Subjects.................................................................................................. 32 10. VIEWS ................................................................................................................................. 34 Creating View File for list Method ..........................................................................................................