Ruby on Rails Web development that doesn’t hurt By Mylore, Dung, Lee, Karen and Bryan

Overview Ruby on Rails Ruby language MVC design pattern AJAX on Rails Ruby on Rails in action

Ruby on Rails Framework written in the Ruby programming language for database- backed web applications Utilizes MVC design pattern Created by David Heinemeier Hansson in mid 2003 and released in 2004 Developed to create the Basecamp project management web application

Philosophy Convention over configuration –Almost no configuration files –Helper scripts to get started Conformity through freebies –Magic wiring relies on common structures due to conventions of Ruby on Rails Best practices by invitation –Auto-generated unit and integration testing

Built-in Functions Helper scripts –Create directory hierarchy and skeleton code –Create model, view and controller objects –Set up database connectivity ActiveRecord –Dynamic method generation Built-in WEBrick web server

Ruby Object Oriented Scripting Language –Interpreted –Open Source –Fully OO that simulates procedurals –Publicly released in 1995 –New but well documented –Based loosely of Eiffel and Ada but heavily influenced by other languages like Perl, Python, Java/JavaScript, etc.

Reflective Language Ruby incorporates many beneficial features of other languages –Flexible programming (Perl) –Built in regex (Perl) –Error and Exception Handling (Python, Java) –Mark and Sweep Garbage Collector (Java) –No variable declaration (Perl, PHP, etc) –Embedded doc tools, RDoc (Java) –No Semicolon ‘;’ ! (Python) –And many others

Highlights: Open Classes Every class, including the core classes can be modified at any time. You just need to call Class class_name #modification code End Example: #modding floats to output in currency class Float def to_m sprintf("$%.2f", self) end

Highlights: Embedded Strings In Perl and PHP you can embed variables into strings. In Ruby you can embed whole blocks of code into string. Just need to put it between #{ } Example: #print out the prices in currency format from an #array without the need to put it back into a #variable p = [1.25, 2.00, 3.15] print “Lily: #{p[0].to_m} Rose: #{p[1].to_m} Viola: #{p[2].to_m}”

Highlights: RHTML Ruby can be directly embedded into HTML much like the way PHP does Example: Names of all the people Name:

Future of Ruby Ruby is easy to learn, simple to understand and friendly to write in It has become quite popular and gained a large following since its release Ruby’s library is expanding rapidly with many modules currently being written for it. And with the soon to be release version 1.9 It’s free!

Rails and the MVC Pattern MVC in PHP/Perl/JSP is hard –Can be done, but requires a lot of work to create a framework to enforce the MVC pattern. –Java (Struts), Perl (Maypole), and for PHP have their own frameworks, but they are not integrated deeply in their respective languages.

Rails and the MVC Pattern RoR integrates and enforces MVC in its framework. Scalability and maintainability. This significantly reduces the amount of repeated code.

Model The Model in RoR wraps to represent the RDBMS tables used for a site. Minimal amount of configuration Based on the Active Record pattern.

View Uses embedded ruby code in.rhtml files. Similar to PHP and JSP...etc…

Controller The controller handles the logic, and responds to user interaction and manipulates the model. Provides CRUD (Create/Read/Update/Delete) operations on the model.

Putting it all together RoR requires minimal configuration for implementing MVC. Once a new RoR project is created, the framework will automatically create the MVC components. Each component will map to each other with little configuration.

AJAX on Rails Ability to incorporate AJAX (Asychronous JavaScript and XML) into Rails-driven sites Contains the Prototype JavaScript library –Works with AJAX functions –Works with Script.aculo.us (additional functionality onto Prototype) Contains helper functions for implementing AJAX

AJAX on Rails No longer a complicated process to incorporate AJAX onto Rails-driven sites Newest version of Rails contains RJS –Create JavaScript using Ruby Reduce the amount of code needed to implement AJAX

Applications and Projects Applications –Instiki Web pages –DRTV Research –Penny Arcade

Applications: Instiki Wiki-based program that focuses on ease of installation and simplicity in running –2 step method for install –Simplistic user interface –Great for notes, brainstorming, organizing gatherings, file sharing, etc. Used for creating and editing web pages –Used for database interaction, syntax interpretation, etc.

Web pages: DRTV Research DRTV Research is a free online application that combines television lineup listings per week with consumer demographic data for North America. Over 700,000 pages of data are available on DRTV Research with new data added daily.

Web pages: Penny Arcade Penny Arcade is among the most popular web-comics currently online, hosting both a children's charity (Child’s Play) and a gaming convention (PAX) each year.

Ruby on Rails: Cons Confined to one language: Ruby Slight Learning Curve Forced to one directory hierarchy Not too popular (Though it is becoming more so recently) Not yet industry standard Relatively new with future stability unknown

Ruby on Rails: Pros Open Source and free! Built for Rapid Application Development Less development time Less lines of code Easy database connectivity MVC design pattern Built-in functions Minimal configuration Well documented AJAX made easy

Simplicity Weblog in 15 minutes! – ke2_with_sound.movhttp://media.rubyonrails.org/video/rails_ta ke2_with_sound.mov Ruby search engine –