Ruby On Rails Rebecca Crabb and Blaine Stancill
Ruby On Rails
Rebecca Crabb and Blaine Stancill
Ruby
• Open-Source Programming Language
• Created by Yukihiro Matsumoto
• Blended parts of other languages
• “I wanted a scripting language that was more powerful
than Perl and more object-oriented than Python”
• Public release in 1995
• Achieved mass acceptance in 2006 with Ruby On Rails
Why Ruby?
• Ruby: puts “Hello World!”
• Java: threeVeryLongLines.weHopeWork…
• Perl: #$<!&;
• Lisp: ((a(((b)))c)))
No, But Really…
Ruby vs Java
Ruby
• The empty program:
Java
•
The empty program:
Class Test {
public static void main(String[] args){}
}
•
• Basic Getters and Setters
class Circle
attr_accessor :radius
end
Basic Getters and Setters
class Circle{
private float radius;
public void setRadius(float radius){
this.radius = radius;
}
public float getRadius(){
return radius;
}
}
Ruby VS JAVA
Ruby
• List:
stuff = [ ]
stuff << “Java”, “Ruby”
Java
• List:
List<String> languages = new
LinkedList<String>();
languages.add(“Java”);
languages.add(“Ruby”);
Objects
• Everything is an object
• Does not have primitives like Java
TypeCasting
“If it walks like a duck and talks like a duck, it’s a duck!”
• The “Duck Typing” philosophy
•
•
Define an object by what it can do, not its type
Current set of methods and properties
• Variable naming
•
•
•
var could be a local variable
@var is an instance variable
$var is a global variable
Ruby on Rails
• Open source web application framework for Ruby
• Designed for Agile development
• Released in July 2004
• In August 2006 Apple announced that it would ship
RoR with Mac OS X Leopard
• Rails provided a purpose for Ruby
• Rails using Model-View-Controller architecture
Philosophy and Design
• Convention over Configuration
• Naming conventions
• Class Sale in the model, the corresponding table in database is
called sales by default
• Less Code
• Don’t Repeat Yourself
• Scaffolding
• Automatically create full CRUD support for database table
• Generators
• Built in scripts to automatically generate parts of framework
MVC Pattern
Active Record
• It’s the M in MVC
• Handles the automatic mapping of your database
tables to your runtime model objects
• Tables to classes
• Rows to objects
• Columns to object attributes
• Don’t need to see or use SQL
• But still can if necessary
• Relational database
Database Access
• team.rb is our model:
class Team < ActiveRecord::Base
has_many
:players
has_one
:coach
belongs_to
:conference
end
• Retrieve all the players:
@team= Team.find_by_school_and_sport(“unc”,”basketball”)
@team.players
The Rails way
• Quick and easy development
• Built for scalability
• Every app is structured the same
• Convention over Configuration
• Don’t Repeat Yourself
ViDeoS
More Info ON RoR
• http://www.ruby-lang.org/en/about/
• http://rubyonrails.org/
• http://onlamp.com/pub/a/onlamp/2005/10/13/wha
t_is_rails.html?page=3
• http://railstutorial.org/chapters/a-demo-app
Questions?
References
• http://www.ruby-lang.org/en/about/
• http://rubyonrails.org/
• http://onlamp.com/pub/a/onlamp/2005/10/13/what_is_
rails.html?page=3
• http://railstutorial.org/chapters/a-demo-app
• http://slideshare.net/Belighted/ruby-vs-java
• http://slideshare.net/vishnu/the-top-10-reasons-the-rubyprogramming-language-sucks
• http://en.wikipedia.org/wiki/Diamond_problem
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