Ruby on Rails
- technical report -
Alex Angelescu, Petrică Manoilă,
Iulian Goriac

RoR/TR - Overview
1. What is Ruby on Rails
2. Basic principles
3. RoR architecture
4. SWOT analysis
5. Demo Web Service client application
6. Conclusions
7. References

RoR/TR - What is Ruby on Rails
Ruby on Rails (RoR) is a web application framework based on
the Ruby programming language, designed in the spirit of
Agile development methodology and used by web developers
for rapid development.

RoR/TR - Basic principles
The Rails philosophy includes several guiding principles:
DRY – “Don’t Repeat Yourself” – suggests that writing
the same code over and over again is a bad thing.
Convention Over Configuration – means that Rails makes
assumptions about what you want to do and how you’re
going to do it, rather than letting you tweak every little
thing through endless configuration files.
REST is the best pattern for web applications –
organizing your application around resources and
standard HTTP verbs is the fastest way to go.

RoR/TR - The MVC Architecture
Models
A model represents the information (data) of the application and the rules to manipulate that data.
In the case of Rails, models are primarily used for managing the rules of interaction with a
corresponding database table. In most cases, one table in your database will correspond to one
model in your application. The bulk of your application’s business logic will be concentrated in the
models.
Views
Views represent the user interface of your application. In Rails, views are often HTML files with
embedded Ruby code that performs tasks related solely to the presentation of the data. Views
handle the job of providing data to the web browser or other tool that is used to make requests
from your application.
Controllers
Controllers provide the “glue” between models and views. In Rails, controllers are responsible for
processing the incoming requests from the web browser, interrogating the models for data, and
passing that data on to the views for presentation.

RoR/TR - The Components of Rails
Action Controller
Action Controller is the component that manages the controllers in a Rails application. The Action
Controller framework processes incoming requests to a Rails application, extracts parameters, and
dispatches them to the intended action. Services provided by Action Controller include session
management, template rendering, and redirect management.
Action View
Action View manages the views of your Rails application. It can create both HTML and XML output
by default. Action View manages rendering templates, including nested and partial templates, and
includes built-in AJAX support.
Active Record
Active Record is the base for the models in a Rails application. It provides database independence,
basic CRUD functionality, advanced finding capabilities, and the ability to relate models to one
another, among other services.

RoR/TR - The Components of Rails (..)
Action Mailer
Action Mailer is a framework for building e-mail services. You can use Action Mailer to send emails
based on flexible templates, or to receive and process incoming email.
Active Resource
Active Resource provides a framework for managing the connection between business objects an
RESTful web services. It implements a way to map web-based resources to local objects with CRUD
semantics.
Railties
Railties is the core Rails code that builds new Rails applications and glues the various frameworks
together in any Rails application.
Active Support
Active Support is an extensive collection of utility classes and standard Ruby library extensions
that are used in the Rails, both by the core code and by your applications.

RoR/TR - REST
REST, an acronym for Representational State Transfer, boils down to two main
principles for RoR purposes:
Using resource identifiers (which, for the purposes of discussion, you can think
of as URLs) to represent resources
Transferring representations of the state of that resource between system
components.
For example, to a Rails application a request such as this:
DELETE /photos/17
would be understood to refer to a photo resource with the ID of 17, and to indicate a
desired action – deleting that resource. REST is a natural style for the architecture
of web applications, and Rails makes it even more natural by using conventions to
shield you from some of the RESTful complexities and browser quirks.

RoR/TR - Strenghts
Ruby on Rails provides a consistent approach to building
web applications with an out of the box architecture
Ruby is a fully featured object-oriented language with a
long history
Rails includes a well thought out object relationship
mapping tool with easy database migrations and rollbacks
Rails includes support for a variety of web technologies
Free, high productivity, high portability

RoR/TR - Weaknesses
The Rails framework is not in widespread use
Scalability & performance
Ruby is one of the slowest dynamic languages known to man
Eats up tons of RAM
Database can quickly become the bottleneck, lots of CPU
time spent, esp. in the OR/M layer
Clusters have to be used to handle even moderate traffic

RoR/TR - Opportunities
"Learn a new language every year! - when you learn a new
language, you learn a new way to think." - Why not Ruby?
The ideea is to learn about web application development
and since Ruby is very high level language this might ease
the assimilation of the new concepts involved.
No team member knows this particular technology so it
will be an interesting way to see how fast and how far
can we grow together starting from zero.

RoR/TR - Threats
Very few jobs asking specifically for Ruby / RoR
expertise - specific knowledge might not be directly
useful in the workforce market

RoR/TR - n-lines code to read the
stock market
require "soap/wsdlDriver"
# WSDL file URL
wsdl = 'http://www.bvb.ro/BSEDelayedWs/Intraday.asmx?wsdl'
#create the driver from WSDL file
driver = SOAP::WSDLDriverFactory.new(wsdl).create_rpc_driver
#call the service
ans = driver.ExchangeStatistics(0)
#harvest response
ans["ExchangeStatisticsResult"]["TypeExchangeStatistics"].each do |tes|
puts "LastSession: #{tes["LastSession"]}"
puts "Marketcode: #{tes["Marketcode"]}"
puts "Volume: #{tes["Volume"]}"
puts "Value: #{tes["Value"]}"
puts "ValueUSD: #{tes["ValueUSD"]}"
puts "ValueEUR: #{tes["ValueEUR"]}"
puts "Trades: #{tes["Trades"]}"
puts
end

RoR/TR - Conclusions
Rails is a fun framework that takes a lot of the drudgery out of
web programming. However, it’s lack of really great IDE support
and static code analysis makes large apps difficult to maintain.
There are also some serious scaling issues. This would be
recommend for smaller projects with low to medium traffic loads.
However, the critical weaknesses of the language and the
framework (e.g., performance) are actively being addressed. So,
even if one doesn't choose to use Rails today, the platform might
offer some pleasant surprises in the future.

RoR/TR - References
Ruby programming language
http://www.ruby-lang.org
RoR site
http://rubyonrails.org
RadRails - Cross-platform RoR IDE:
http://aptana.com/radrails
Tutorials:
http://guides.rubyonrails.org/getting_started.html
http://api.rubyonrails.org

Thank You!