The presentation gives an overview about the ruby programming language and Rails, the web framework built over it ruby. It does highlight some of the key features of ruby programming language and mentions the key benefits of using Rails framework for web application development.
3. INTRODUCTION
Ruby on Rails, sometimes known as "RoR" or just Rails, is an open source
framework for Web development in Ruby, an object-oriented programming
(OOP) language similar to Perl and Python.
The principle difference between Ruby on Rails and other frameworks for
development lies in the speed and ease of use that developers working within
the environment enjoy.
Changes made to applications are immediately applied, avoiding the time
consuming steps normally associated with the web development cycle.
4. NOW, WHAT’S A WEB AppLICATION ??
A web application is an application that is accessed via web browser over
a network such as the Internet or an intranet. The web Application consists
of a browser, an application and a database.
The browser makes a request to the web application, which then interacts
with the database, and produce suitable output and sends it back to the
browser.
5. WHAT’S RUBY ?
Ruby is a dynamic, reflective, general purpose object-oriented
programming language that combines syntax inspired by Perl with
Smalltalk-like features.
Ruby originated in Japan during the mid-1990s and was initially
developed and designed by Yukihiro "Matz" Matsumoto. It is based on
Perl, Smalltalk, Eiffel, Ada, and Lisp.
Ruby supports multiple programming paradigms, including
functional, object oriented, imperative and reflective. It is similar in
varying respects to Python, Perl, Lisp, Dylan, and CLU.
6. FEATURES OF RUBY !!
Objects everywhere! - In Ruby everything is an object including simple
numeric values. Here is an example,
Blocks - Blocks is a powerful feature in Ruby which simplifies
programming. Blocks are code blocks which can be passed as a parameter
to a method. Using this feature it is easy to build code libraries which can
delegate varying functionality to code blocks to be built later.
Implicit return value in methods - Value of the last expression in a
method becomes the return value of the method. In Ruby return keyword is
optional.
7. In Ruby everything is open! - In Ruby you can easily extend classes
and modules. This means that nothing in Ruby (including built in classes and
modules) are closed!. Interestingly additional methods can be added to a
class even at runtime.
Ruby supports parallel assignment - It is possible to change multiple
variables in a single assignment. The best example is the swapping of two
variable.
In Ruby strings are mutable - In Ruby it is possible to change a string
variable in place. Hence unlike Java, the same string literal when used
multiple times will point to different object instances.
True and false in Ruby - In Ruby only nil and false evaluate to false.
This means that everything else evaluates to true! Hence even the value 0
evaluate to true in ruby.
8. SIMPLE RUBY PROGRAM TO ADD TWO
NUMBERS
# define a function called addtwo with two parameters
def addtwo(a, b)
a + b; # return a + b
end
print "Please enter number 1 : "; # get the input from the console,
val1 = gets;
print "Please enter number 2 : ";
val2 = gets;
# convert the string console inputs to_i (to_integers) and add together
print "Answer : " , (val1.to_i + val2.to_i), "n";
9. JAvA vS RUBY !!
•Ruby is interpreted, Java is compiled (before being interpreted)
>ruby my_program.rb
• Code can be loaded at runtime
• Code is easily accessible
• Speed performance issues
>javac MyProgram.java
>java MyProgram
10. RUBY USE DYNAMIc TYPING
• Values have type, variables not
• Decrease language complexity
- No type declaration
- No type casting
• Increase flexibility
• Errors appears at run-time
14. ON A BUSINESS POINT Of vIEW ! !
• Java is a well-known technology
• Lots of developments have been made with it
• Easy to find experts
• Still not that much available Ruby developers
16. WHAT IS RAILS ??
Rails is a web-application framework that includes everything needed to
create database-backed web applications according to the Model-ViewControl pattern.
Ruby on Rails was extracted by David Heinemeier Hansson from his work
on Basecamp, a project management tool by 37signals (now a web
application company).
Like many contemporary web frameworks, Rails uses the Model-ViewController (MVC) architecture pattern to organize application programming.
17. WHAT IS A WEB FRAMEWORK ??
A web application framework is a software framework that is
designed to support the development of dynamic websites, Web applications
and Web services. The framework aims to alleviate the overhead associated
with common activities performed in Web development.
For example, many frameworks provide libraries for database access,
templating frameworks and session management, and often promote code
reuse.
Some of the main features of web framework is that they provide
security,database access and mapping,URL mapping,Web template
system,caching,AJAX ,Automatic Configurations and so on.
18. MVC ARCHITECTURE
Model–view–controller (MVC) is an architectural pattern used in
software engineering. The pattern isolates business logic from input and
presentation, permitting independent development, testing and maintenance
of each.
These frameworks use actions that do the required processing, and then
"push" the data to the view layer to render the results. These frameworks
start with the view layer, which can then "pull" results from multiple
controllers as needed.
19. MODEL- Used for persistence and relationships.
VIEW- Used for displaying the data.
CONTROLLER- The logic of the application.
20. FEATURES OF RUBY ON RAILS
Ruby on Rails is separated into various packages, namely ActiveRecord(an
object-relational mapping system for database access), ActiveResource
(provides web services), ActionPack , ActiveSupport and ActionMailer.
Prior to version 2.0, Rails also included the Action Web Service package
which is now replaced by Active Resource.
Apart from standard packages, developers can make plugins to extend
existing packages.
22. RAILS VS J2EE
Both have a learning curve.
RAILS has the edge in productivity by a significant margin.
J2EE currently has an edge in scalability. If it’s a client facing system for
millions of concurrent users – use J2EE.
If it’s an internal web application, definitely take a look at this technology as
a possible way of shortcutting the long development time for a J2EE web
application.
24. AppLICAtIOnS OF ROR !!
Ruby On Rails have been in use now by over 500 websites.
Some of the leading websites using
yellowpages.com, lumosity.com and so on.
RoR
are
43things.com,
Ruby on Rails is Picking up the pace and have become more and more
viable in the business scenario.
25. COnCLuSIOn
RoR an evolving Toolset.
Ruby is what makes Rails special, the interest in general Ruby
programming will continue to expand rapidly
RoR can be best used for small web based applications requring
parallel development.
