This document provides an introduction to the Ruby programming language in 3 sentences: Ruby is a balanced programming language that blends elements of other popular languages and is known for its expressiveness, terse syntax, and rich set of tools and frameworks that provide immediate feedback to developers. It is an opinionated language that favors conventions over rigid configurations and provides a full development environment through its ActiveRecord ORM, MVC framework structure, and testing tools like RSpec. Major companies like GitHub, Heroku, Twitter, and Hulu use Ruby for both web and system programming.

1. this is the 0.8 language you were looking for

2. class << self
def who Maurizio De Magnis
I’m a Developer,
trying to improve
*
http://olistik.me
@olistik
def what
def where

3. First things first
let's sculpt this presentation

4. What you're NOT going to see today
“C’mon, use Ruby so I can
eat meat this week”
“Pick me! Pick me!”

5. What I'm going to say
is a personal remix of
what I've experienced,
heard and read.
http://goo.gl/TPywyp

6. Will you see breakthrough concepts here?
http://goo.gl/4FhtgR

7. No.

8. I'll just give you another point of view

9. ● Ruby is NOT a perfect language
● Ruby is NOT the best language for
every scenario

10. "a language can’t be
good for everyone and
every purpose, but we
can strive to make it
good for 80% of what is
needed in a
programming language"
The most important slide so far
Yukihiro ‘Matz’ Matsumoto
(creator of Ruby)
http://goo.gl/0p7tBv

11. so do good/great programming
languages (and frameworks)

12. http://www.ruby-lang.org/en/about/
"Ruby is a language of careful balance.
Its creator, Yukihiro “Matz” Matsumoto, blended
parts of his favorite languages
(Perl, Smalltalk, Eiffel, Ada, and Lisp)
to form a new language that balanced
functional programming with imperative
programming."

13. ● everyone has good ideas
● BUT not everyone perform well
Let's talk about something that
matters
http://goo.gl/60awJp

15. How?
perform well := adaptability to changes
either in the early stages (prototype)
or in the subsequent evolutions

16. Recipe for success
people
(skilled and motivated)
processes
(agile!)
but also the tools

17. on the coding layer
Let’s focus

18. coding is a creative process
positive thoughts unleash creativity
if coders are happy then creativity boosts

19. Provide them tools that actually improves the
efficiency of their environment
(also, pay them well enough so that they
don't worry about the economic details)
A good way to make
coders happy

20. The code you have to actually type
is the code you wish you had.
Today’s definition for
EPIC WIN

21. Expressiveness #1
The language you use influences your thoughts

22. Expressiveness #2
What about a language that looks like written
english?

23. “In the 1970s, researchers found that
developers tend to write roughly the
same number of lines of code every
day, regardless of what language
they're working in.”
Terseness #1
B. Boehm, Software Engineering Economics, Prentice-Hall, ISBN 0-138-22122-7, 1981.

24. Terseness #2
"the first 10 book's title, ordered alphabetically"
(it’s actually shorter than the corresponding english sentence)

25. Immediate feedback
I want to be able to “play” with the data:
Don't limit my designing skills
(testing new ideas)
Don't limit my problem solving skills
(debugging)

26. Immediate feedback - IRB
.js: 1
.css: 1
.rb: 21
.erb: 1
.yml: 3
.ru: 1
.lock: 1
.log: 1
.html: 3
.ico: 1
.txt: 1
.rdoc: 1

27. Immediate feedback - Rails console

28. Immediate feedback - meet AREL

29. Immediate feedback - meet AREL #2
Ruby code that gets transparently translated
into (usually) boring/verbose SQL statements.
Regardless the DBMS you're using
(MySQL, Postgres, SQLite, etc.)
Why? Abstraction!
"perform well := adaptability to changes"

31. “My code does
something funky, let
me inspect its context
at runtime”
Immediate feedback - MOAR

32. Immediate feedback - MOAR
Better
Errors

33. Immediate feedback - MOAR
RailsPanel

34. The pitfall of most frameworks
“Be the best at all the things!”
It usually ends up for the framework to be less
than average.
Even worse: “Let's do it by configuring all
the things!” (every time, from scratch)
=> a lot of time effort

35. Rails is an opinionated framework

36. Conventions over
configurations
A lot of assumptions based on what are the
most common needs of web developers.

37. ● console
● standalone app server (but you can
choose whatever you like)
Fully isolated development
environment

38. Code organization
Follows the MVC pattern:
The goal is to understand in almost zero time
where a file is or should be located.
app/
models/
views/
controllers/

39. Code organization #2
Tends to fight bad practices such as:
● single directory with hundreds of files
● few huge monolithic files

40. Data persistence: ActiveRecord
class Author < ActiveRecord::Base
end
The code above reflects this database
configuration:
- authors
id: integer

41. Data persistence: ActiveRecord #2
If the database table happens to contain
additional fields like "name" and "age" the
developer doesn't need to update any code in
order to perform these:
author = Author.take(name: 'PKD')
author.age # => 55
author.age = 53
author.save

42. Data persistence: ActiveRecord #3
Even relations are easily mapped with little
effort:
class Author < ActiveRecord::Base
has_many :books
end
class Book < ActiveRecord::Base
belongs_to :author
end
- authors
id: integer
- books
id: integer
author_id: integer
author.books.first
author.books.destroy_all
author.books << Book.create

43. Here are some of the tools that makes Ruby
shine.
The focus should not be placed into what
they do, but how they have been
architectured so that your effort consists only
in declaring your needs.
When you use Ruby, you
get the whole ecosystem
for free

44. $ irb
> require 'mini_magick'
> image = MiniMagick::Image.open("input.jpg")
> image.resize "100x100"
> image.write "output.jpg"
$ gem install mini_magick

45. $ irb
> require ‘nokogiri’
> require 'open-uri'
> doc = Nokogiri::HTML(open("http://www.nytimes.com"))
> puts doc.
css('.story h3').
map {|story| "- #{story.text.strip}"}
- Obama's Battle for Votes on Syria Strike Is Taut and Uphill
- In Egypt, a Welcome for Syrian Refugees Turns Bitter
- Facing Fury Over New Law, Stoli Says '€˜Russian? Not Really'
- Two Men, 58 Years and Counting
- Editorial: Banning a Pseudo-Therapy
- Loose Ends: My Adventures in Their Clutches
$ gem install nokogiri

46. "RSpec is testing tool
for the Ruby
programming language.
Born under the banner
of Behaviour-Driven
Development,
it is designed to make
Test-Driven
Development a
productive and
enjoyable experience"
Testing with RSpec
# spec/bowling_spec.rb
require 'bowling'
describe Bowling, "#score" do
it "returns 0 for all gutter game"
do
bowling = Bowling.new
20.times { bowling.hit(0) }
bowling.score.should eq(0)
end
end
$ rspec bowling_spec.rb --format nested
Bowling#score
returns 0 for all gutter game
Finished in 0.007534 seconds
1 example, 0 failures

47. Who uses Ruby?
● http://www.shopify.com/
● http://www.yellowpages.com/
● https://github.com/
● https://www.heroku.com/
● https://twitter.com
● http://www.hulu.com/
● http://www.scribd.com/
● http://www.slideshare.net/
● http://www.soundcloud.com/
● http://www.prada.com
Ruby is used for both web and system programming
Ruby is used by both startups and enterprise companies
(Someone you might know)

48. This brief introduction is just to be
considered as a teaser.

49. Have Fun & Happy Coding