1. RUBY ON RAILS
the beginning

2. ANY IDEAS?

4. RUBYONRAILS.ORG

5. RUBY-LANG.ORG

6. PROGRAMMING
LANGUAGE WEB FRAMEWORK

7. Ruby on Rails is an open-source
web framework that’s optimized
for programmer happiness and
sustainable productivity.
It lets you write beautiful code
by favoring convention over
configuration.

8. Ruby on Rails is an open-source
web framework that’s optimized
for programmer happiness and
sustainable productivity.
It lets you write beautiful code
by favoring convention over
configuration.

9. Ruby on Rails is an open-source
web framework that’s optimized
for programmer happiness and
sustainable productivity.
It lets you write beautiful code
by favoring convention over
configuration.

10. Ruby on Rails is an open-source
web framework that’s optimized
for programmer happiness and
sustainable productivity.
It lets you write beautiful code
by favoring convention over
configuration.

11. Ruby on Rails is an open-source
web framework that’s optimized
for programmer happiness and
sustainable productivity.
It lets you write beautiful code
by favoring convention over
configuration.

12. 80/20
Pareto principle

13. DON’T
REPEAT
YOURSELF

14. DON’T
REPEAT
YOURSELF

15. DUPLICATION
IS
EVIL

16. DUPLICATION
IS
EVIL

17. RUBY

18. Why an other
programming
language?

19. Some might like this, but it's
mostly because most Software
Development Tools are designed
for computers, not for human
beings.

20. Some might like this, but it's
mostly because most Software
Development Tools are designed
for computers, not for human
beings.

21. Some might like this, but it's
mostly because most Software
Development Tools are designed
for computers, not for human
beings.

22. “Ruby is simple in
appearance, but is
very complex inside,
just like human body”
Yukihiro “Matz” Matsumoto,
Creator of Ruby

23. MAKE THE
COMPUTER
WORK FOR YOU

24. DESIGN THE
LANGUAGE AND
LIBRARIES FOR
PEOPLE FIRST

25. LET OTHERS
CARE ABOUT
PERFORMANCE

26. say = “I love Ruby”
puts say
=> “I love Ruby”

27. say = “I love Ruby”
say[‘love’] = “*love*”
puts say.upcase
=> “I *LOVE* RUBY”

28. 4.times { puts say }
=> “I *love* Ruby”
=> “I *love* Ruby”
=> “I *love* Ruby”
=> “I *love* Ruby”

29. Time.now + 1.day
=> Fri Jul 30 17:48:05 +0300 2010

30. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

31. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

32. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

33. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

34. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

35. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

36. Ruby is a dynamic, open source
programming language with a focus
on simplicity and productivity.
It has an elegant syntax that is
natural to read and easy to write.

37. LESS IS MORE

38. JAVA
public static String reverseString(String source) {
int i, len = source.length();
StringBuffer dest = new StringBuffer(len);
}
for (i = (len - 1); i >= 0; i--)
dest.append(source.charAt(i));
return dest.toString();
reverseString("Krawutzikapuzi");
=> "izupakiztuwarK"

39. PHP
strrev("Krawutzikapuzi");
=> "izupakiztuwarK"

40. RUBY
"Krawutzikapuzi".reverse
=> "izupakiztuwarK"

41. RUBY
"Krawutzikapuzi".split(//).inject(""){ |m,c| c + m }
=> "izupakiztuwarK"
Not using the built-in “reverse” method. Still much smaller that Java.

42. COMPLETE
OBJECT
ORIENTATION

43. 10.class
=> Fixnum

44. Fixnum.object_id
=> 108610

45. (10*10).class
=> Fixnum

46. (10*10*10*100000).class
=> Bignum

47. class String
def method_missing(method)
puts "intercepting call to #{method}"
end
end
"Lorem ipsum dolor".krawutzikaputzi
=> "intercepting call to krawutzikaputzi"

48. >> Post.find_by_published(true)
=> #<Post id: 1, title: "Hallo FH!", body:
"Lorem ipsum dolor sit amet, consectetur
adipisicing...", published: true, created_at:
"2008-04-14 12:07:46", updated_at:
"2008-04-14 12:07:46">

49. >> Post.find_by_published(true)
=> #<Post id: 1, title: "Hallo FH!", body:
"Lorem ipsum dolor sit amet, consectetur
adipisicing...", published: true, created_at:
"2008-04-14 12:07:46", updated_at:
"2008-04-14 12:07:46">

50. RAILS

51. MVC

52. MVC
(model-view-controller)
Controller
Model View

53. MVC
(model-view-controller)
Controller
Model View

54. MVC
(model-view-controller)
DB Helper
Controller
Model View

55. REST

56. IN THE BEGINNING
THERE WAS THE URL

57. http://pluspoker.true-vision.net/content/index.html

58. http://www.merriam-webster.com/cgi-bin/mwwod.pl

59. http://gilesbowkett.blogspot.com/search?updated-
max=2008-04-08T09%3A25%3A00-07%3A00&max-results=7

60. http://www.amazon.de/gp/ product/B0000262LH/ ref=s9subs_c3_img1-
rfc_p_19_32_31_9_9? pf_rd_m=A1IDDPBG1NC5TQ&pf_rd_
s=center-2&pf_rd_r=1FMGVYJN44 H7WQD9YCR9&pf_rd_t=101&pf_rd_
p=139524591&pf_rd_i=301128

61. REST
(Representational State Transfer)

62. WEB APPLICATION
USUALLY CONSISTS
OF OBJECTS

63. (like, say, blog posts)

64. WHAT IS A BLOG POST?

65. BLOG POST
It’s an entry in a database.
Consists of title, body, date,
and other data.

66. HTML REPRESENTATION
http://0.0.0.0:3000/posts/1

67. XML REPRESENTATION
<?xml version=“1.0” encoding=“UTF-8”?>
<post>
<id type=“integer”>1</id>
<title>Another title</title>
<body>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do
eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad
minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex
ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat
cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id
est laborum.</body>
<created-at type=“datetime”>2008-04-14T12:07:46+02:00</created-at>
<published type=“boolean”>true</published>
<updated-at type=“datetime”>2008-04-15T11:30:50+02:00</updated-at>
<version type=“integer”>2</version>
</post>
http://0.0.0.0:3000/posts/1.xml

68. def show
@post =
Post.find(params[:id])respond_to do |
format|
format.html
format.xml { render :xml => @post }
end
end

69. RESTFUL OPERATIONS
• create
• read
• update
• delete

70. HTTP VERBS

71. in HTTP each request is preceeded
by a request type, or “verb”.

72. Normal page loads use the “GET” verb,
while web forms use “POST”.

73. HTTP knows more verbs, most
importantly “PUT” and “DELETE”.

74. REST operation HTTP verb
Create POST
Read GET
Update PUT
Delete DELETE

75. GET http://localhost:3000/posts/1

76. DELETE http://localhost:3000/posts/1

77. GET http://localhost:3000/posts
GET http://localhost:3000/posts/1
POST http://localhost:3000/posts
PUT http://localhost:3000/posts/1
DELETE http://localhost:3000/posts/1

78. The best thing is
that Rails does it all
completely
automatically.

79. ROUTING

80. map.resources :posts

81. map.sign_up 'sign_up/', :controller => 'registrations', :action => 'new'
GET http://localhost:3000/sign_up/

82. map.resources :videos do |videos|
videos.resources :comments
videos.like '/like', :controller => 'favorites', :action => 'create'
end
map.resources :poker_rooms, :member => { :move_up => :get, :move_down => :get }
map.resources :favorites
map.resources :users
map.sign_up 'sign_up/', :controller => 'registrations', :action => 'new'
map.edit_registration 'user/edit', :controller => 'registrations', :action => 'edit'
map.sign_in 'sign_in/', :controller => 'sessions', :action => 'new'
map.sign_out 'sign_out/', :controller => 'sessions', :action => 'destroy'
map.resources :registrations, :only => [ :create, :update, :destroy ]
map.resources :sessions, :only => [ :create, :destroy ]
map.root :controller => 'videos', :action => 'preview'

83. ORM
(OBJECT RELATIONAL MAPPING)

84. Post.find 1

85. Post.find 1
SELECT * FROM posts
WHERE posts.id = 1
LIMIT 1

86. Post.find_all_by_title ‘Hello World’
SELECT * FROM posts
WHERE posts.title = ‘Hello World’

87. class Post < ActiveRecord::Base
belongs_to :user
end
class User < ActiveRecord::Base
has_many :posts
end

88. @user = User.first
SELECT * FROM users LIMIT 1
@user.posts
SELECT * FROM posts WHERE
posts.user_id = 1

89. GENERATORS

90. rails pluspoker

91. script/generate model user username:string age:integer

92. script/generate controller users

93. script/generate migration add_active_to_users active:boolean

94. NEED MORE?

95. WRITE YOU OWN!

96. RAILS IS 100% RUBY-WRITTEN

97. MONGREL

98. MONGREL
• Very lightweight
• Single request server
• Ideal for local use

99. Browser Mongrel

100. SERVER SIDE

101. Mongrel
Mongrel
Apache
Browser
nginx
Mongrel
Mongrel

102. Thread
Thread
...
Apache Passenger
Browser
nginx mod_rails

103. Q&A