RubyKaigi 2013 http://www.ustream.tv/recorded/33609885 (ja)

1. Rails Gems realize RESTful
modeling patterns
@tkawa
RubyKaigi 2013, June 1

2. @tkawa
Ruby programmer (2000-)*
RESTafarian (2005-)
inspired by @yohei
Rails programmer (2006-)*
Sendagaya.rb (2012-)
Toru KAWAMURA
* with some blank of career

3. Sendagaya.rb 『千駄ヶ谷.rb』
Every Monday 19:00 - 21:30

4. Sendagaya.rb
Organized by @ppworks, @fukajun, and me
Concept: Looking forward to the weekly
meetup makes our everyday working fun
Held currently at Shinjuku(!?), formerly at
Sendagaya
#50 anniversary on June 3!
sendagayarb.github.io

5. Rails Gems realize RESTful
modeling patterns
@tkawa

6. Rails Gems realize RESTful
resource modeling patterns
@tkawa

7. Point of Departure

8. Rails is RESTful

9. Since RubyKaigi 2006
June 11, 2006

10. # config/routes.rb
Foobar::Application.routes.draw do
resources :users
end

11. resources :users

12. GET /users users#index
POST /users users#create
GET /users/new users#new
GET /users/:id/edit users#edit
GET /users/:id users#show
PUT /users/:id users#update
DELETE /users/:id users#destroy
$ rake routes

13. GET POST PUT DELETE
/users index create - -
/users/:id show - update destroy
in addition, “new” and “edit” as supplementary resources

14. resources :users
That’s it.
That makes for really simple design.

15. REST’s advantage is...

16. Simple
Consistent
To reap the benefits of
HTTP (“HTTP way”)
Generally:

17. Easy to design
Easy to understand
On Rails “resources”
particularly:

18. “resources” makes it
easy to design
For developer him/herself
“resources” decides on a resource form
All you have to do is to decide on a
resource name, such as “users”
/user/1 /users/1 /users/user/1 /users/user-1

19. “resources” makes it
easy to understand
For developer him/herself, co-developer,
and external developer (e.g. using API)
Suggest that there are corresponding
controller, model, view, etc, such as
UsersController, User model

20. “resources” makes it
easy to design & understand
Rails has demonstrated that
this simplicity goes well
“Constraints are liberating”

21. You might think it does not
go well in these cases:

22. Authentication
Search
State changes
Execution of procedural operation
Operation to a list / Sort
Wizard / Confirmation page

23. Authentication
Search
State changes
Execution of procedural operation
Operation to a list / Sort
Wizard / Confirmation page
How do I write routes.rb?
How about Controller? Model?

24. We need another technique.
But...

25. resources :users

26. GET POST PUT DELETE
/users index create - -
/users/:id show - update destroy
in addition, “new” and “edit” as supplementary resources

27. GET POST PUT DELETE
/users index create - -
/users/:id show - update destroy
This is a pattern

28. “resources” makes it
easy to design & understand

29. A pattern makes it
easy to design & understand

30. “resources” is the fundamental pattern
If there is a smaller and more concrete
pattern, we can design well accordingly
We want more (concrete)
patterns!

31. コストがかかるかもしれない問題解決を実際に行う
前の先行調査として大変役に立つ
パターンには名前がついていることが重要である。な
ぜなら、名前がついていることで問題や解決策を記
述したり、会話の中で取り上げたりすることができ
るようになるからである
ja.wikipedia.org/wiki/デザインパターン_(ソフトウェア)
A pattern is not a wild card,
but a card with many benefits

32. Using a pattern is similar
to Rails way, and...

33. We have “RubyGems”

34. Suppose a gem provides the
implementation of a specific pattern
Then routes.rb will be the description of
the patterns to be used

35. Discover the pattern
from RubyGems

36. Authentication
Search
State changes
Execution of procedural operation
Operation to a list / Sort
Wizard / Confirmation page

37. Authentication
“Sign in” / “Sign out”
Those are represented as what?

38. devise.plataformatec.com.br
Devise
by Plataformatec

39. GET /users/sign_in devise/sessions#new
POST /users/sign_in devise/sessions#create
DELETE /users/sign_out devise/sessions#destroy
…
# config/routes.rb
devise_for :users

40. “Sessions” is a resource
(that doesn’t involve a model)
GET /users/sign_in devise/sessions#new
POST /users/sign_in devise/sessions#create
DELETE /users/sign_out devise/sessions#destroy
…
# config/routes.rb
devise_for :users

41. Session is singular
Only one “authentication session” for
each user

42. Session Resource pattern
Proposal
GET /session
PUT(POST) /session →sign in
DELETE /session →sign out
rest-pattern.hatenablog.com/entry/session-resource

43. Singular resource in Rails
resources :users
resource :user

44. resource :session

45. POST /session sessions#create
GET /session/new sessions#new
GET /session/edit sessions#edit
GET /session sessions#show
PUT /session sessions#update
DELETE /session sessions#destroy
$ rake routes

46. GET POST PUT DELETE
/session show create update destroy
in addition, “new” and “edit” as supplementary resources

47. GET POST PUT DELETE
/session show create update destroy
This is also a pattern

48. Authlogic
github.com/binarylogic/authlogic
by Ben Johnson of Binary Logic

49. # app/models/session.rb
class Session < Authlogic::Session::Base
end

50. # app/models/session.rb
class Session < Authlogic::Session::Base
end
If they have no model, let them create it.
(not an ActiveRecord)

51. # app/controllers/sessions_controler.rb
class SessionsController < ApplicationController
# POST /session
def create
@session = Session.new(session_params)
if @session.save
flash[:notice] = "Login successful!"
redirect_back_or_default account_url
else
render :action => :new
end
end
end

52. resource :session
Rails way!!

53. I wish Devise were like that...
I’m planning to do this...

54. Authentication
Search
State changes
Execution of procedural operation
Operation to a list / Sort
Wizard / Confirmation page

55. Search
Search for users with the name that
contains “tkawa”
Search for users that were created before
2012

56. Ransack
github.com/ernie/ransack
by Ernie Miller

57. GET /users?q[name_cont]=tkawa
GET /users?q[created_at_lt]=2013-01-01

58. Search from collection
= Filtering

59. Filtered Collection pattern
Proposal
/users?role=admin
/users?since_id=123
/users?page=2
rest-pattern.hatenablog.com/entry/filtered-collection

60. Kaminari
github.com/amatsuda/kaminari
by Akira Matsuda
GET /users?page=2&per=10

61. I wish I could use query parameters
like models (w/ validation)...

62. class PostsController < ApplicationController
private
def filter_params # using strong parameters
@_filter_params ||= begin
params.default( # you can set default value
per: '10'
).permit(
:date, :q, :page, :per
).validate( # you can validate like a model
date: { format: /Ad{4}-d{2}-d{2}Z/ },
q: { length: { maximum: 20 } }
)
end
end
helper_method :filter_params
end
github.com/tkawa/collection_filter
Query parameters like models

63. Authentication
Search
State changes
Execution of procedural operation
Operation to a list / Sort
Wizard / Confirmation page

64. Wizard
Enter data in multiple steps with page
transitions

65. Wicked
by Richard Schneeman
github.com/schneems/wicked

66. GET /user_steps/personal
PUT /user_steps/personal
GET /user_steps/social
PUT /user_steps/social
GET /user_steps/finish

67. Partial Resource pattern
Proposal
/users/1/personal
/users/1/name,email
/users/1?fields=name,email
rest-pattern.hatenablog.com/entry/partial-resource
Provides only some attributes (fields)
to GET/PUT

68. Transaction Resource pattern
Proposal
POST /transactions
PUT /transactions/123
PUT /transactions/123/committed
rest-pattern.hatenablog.com/entry/transaction-resource

69. Rest of patterns are...
Proposal
Filtered Subresource
Multi-member Resource
Private Resource / Private Namespace
Implicit Collection
rest-pattern.hatenablog.com

70. Conclusion

71. RESTful patterns including “resources”
are significant
Focusing on these patterns encourages
good resource design
RubyGems are also useful for this purpose

72. If you are at a loss on
resource modeling...
Focus on gems’ pattern
You will come up with the right resource
by referring to the design of a good gem
“resources” is fundamental
Diverging from the “resources” is the
last resort

73. If you are creating a gem...
You should consider designing around
resources, if possible
Let's stick to the fundamentals of
“resources”
And your gem will realize a pattern!

74. Thank you for your attention.
Let me know if you discover
more patterns!
rest-pattern.hatenablog.com