This document provides an introduction to Ruby on Rails, including: - An overview of the Model-View-Controller framework and REST architecture that Rails is built on - Examples of basic Rails concepts like ActiveRecord and routing - A "Hello World" example using the Ruby language - Explanations of key Ruby concepts like blocks and duck typing

1. +
Introduzione a Ruby on Rails
Ing. Danilo Torrisi
Direttore Tecnico in Priceen
23 Luglio 2012,
Green Hub Catania

2. Sommario
• Introduzione
‣ Model View Controller
‣ REST
• Concetti Base
‣ ActiveRecord
‣ Validation
‣ Routing
• Hello World!

3. Introduzione
Ruby on Rails

4. Introduzione
Ruby on Rails
“ is an open-source web framework that’s
optimized for customer happiness and
sustainable productivity ”
rubyonrails.com

5. Introduzione
Ruby on Rails

6. Introduzione
Ruby on Rails
“Powerful web applications that formerly might
have taken weeks or months
to develop can be produced in a matter of days”
Tim O'Reilly, Founder of O'Reilly Media

7. Chi lo usa?

8. Chi lo usa?

9. Introduzione
Ruby on Rails

10. Introduzione
Ruby on Rails

11. Introduzione
Ruby on Rails
5.times do
puts "Hello world"
end

12. Introduzione
Ruby on Rails
5.times do def show
puts "Hello world" @post = Post.find(params[:id])
end end

13. Ruby
• Linguaggio interpretato ad oggetti
• Fortemente dinamico
5.times do
• Basato sul concetto di blocco puts "Hello world"
end
• Tipizzazione dinamica

14. Ruby
• Linguaggio interpretato ad oggetti
• Fortemente dinamico
5.times do
• Basato sul concetto di blocco puts "Hello world"
end
• Tipizzazione dinamica

15. Ruby
• Linguaggio interpretato ad oggetti
• Fortemente dinamico
5.times do
• Basato sul concetto di blocco puts "Hello world"
end
• Tipizzazione dinamica
Duck Typing “if it looks like
a duck, and quacks like a
duck, it must be a duck”

16. Hello World
5.times do
puts "Hello world"
end
=> “Hello World”
=> “Hello World”
=> “Hello World”
=> “Hello World”
=> “Hello World”

17. Hello World
5.times do
puts "Hello world"
end
=> “Hello World”
=> “Hello World”
=> “Hello World”
=> “Hello World”
=> “Hello World”

18. Hello World
5.times do
puts "Hello world"
end

19. Hello World
Costante numerica?
5.times do
puts "Hello world"
end

20. Hello World
Costante numerica?
5.times do
puts "Hello world"
end

21. Hello World
Istanza della classe Integer
5.times do
puts "Hello world"
end

22. Hello World
Istanza della classe Integer
5.times do
puts "Hello world"
end
Tutto in Ruby è un oggetto

23. Hello World
Metodo times della classe Integer
5.times do
puts "Hello world"
end

24. Hello World
5.times do
puts "Hello world"
end

25. Hello World
5.times do
puts "Hello world"
end

26. Hello World
5.times do
puts "Hello world"
end

27. Hello World
puts "Hello world"
5.times do puts "Hello world"
puts "Hello world" puts "Hello world"
end puts "Hello world"
puts "Hello world"

28. Hello World
5.times do
puts "Hello world"
end

29. Hello World
5.times do 5.times do |i|
puts "Hello world" puts i.to_s
end end

30. Recap
5.times do
Ruby puts "Hello world"
end

31. Recap
5.times do
Ruby puts "Hello world"
end
PHP

32. Recap
5.times do
Ruby puts "Hello world"
end
for ($i = 1; $i <= 5; $i++) {
PHP echo "Hello World"
}

33. Recap
Ruby
PHP

34. Recap
Ruby
if ($users <= 0) {
PHP }
echo "No users"

35. Recap
Ruby puts "No users" if users <= 0
if ($users <= 0) {
PHP }
echo "No users"

36. Introduzione
Ruby on Rails
5.times do def show
puts "Hello world" @post = Post.find(params[:id])
end end

37. Rails
• Web Framework Open-Source
• Paradigma Model View Controller def show
@post = Post.find(params[:id])
• Manutenibilità e riuso del codice end
• Paradigma REST

38. Model View Controller

39. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

40. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

41. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

42. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

43. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

44. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

45. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

46. Model View Controller
<?php
// Connect to mysql database. Ignore the mysql_select_db for now.
$db = mysql_connect($hostname,$username,$password)
X
// Get all the users data.
$result = mysql_query("SELECT * FROM users");
// Display some table..
echo '<table .....';
// Now fetch the the array.
while ($row = mysql_fetch_array($result)) {
// And display the row.
echo 'ID: '.$row{'id'}.' Name: '.$row{'name'}.'</br>';
}
?>

47. Model View Controller

48. Model View Controller
Configurazione Connessione Query
Database Database Database
HTML Layout Autorizzazione
Dynamic PHP Data Sessioni Gestione Errori

49. Model View Controller

50. Model View Controller
Controller
Model View

51. Model View Controller
Controller
Model View

52. Model View Controller
Controller
Model View

53. Model View Controller
Controller
Model View

54. RES T
• Architettura distribuita
• Utilizza protocollo HTTP
• Ogni elemento è detto risorsa http://
• Set di operazioni standard
• Utilizza i verbi HTTP ovvero GET,
POST, PUT, DELETE

55. RES T
http://www.twitter.com/api/

56. RES T
GET http://www.twitter.com/api/ tweets/ index

57. RES T
GET http://www.twitter.com/api/ tweets/ index
Risorsa

58. RES T
Azione
GET http://www.twitter.com/api/ tweets/ index
Risorsa

59. RES T
GET tweets/ index Ritorna tutti i tweet
GET tweets/ 1 Ritorna il tweet id=1
GET tweets/ new Ritorna un nuovo tweet
POST tweets/ create Aggiungi un nuovo tweet
GET tweets/ 1/ edit Ritorna il tweet id=1 da modificare
PUT tweets/ 1/ update Modifica il tweet id=1
DELETE tweets/ 1/ destroy Cancella il tweet id=1

60. Demo