Beyond the Rails Way - Clean Architecture

About architecture to make skinny models and skinny controllers

Transcript

1. Beyond the Rails Way
2. 2 Patricia Luz Bastos
3. 3 Architecture
7. 7 Not so good
8. 8 class UserGroupsController def create # Assume @group is loaded from a before_action method if !current_user.is_old_enough_to_join_group?(@group) flash[:alert] = I18n.t('admin.trestle.flash.too_young') elsif current_user.is_group_limit_reached? flash[:alert] = I18n.t('admin.trestle.flash.too_many_groups') else user_group = UserGroup.new(user_id: current_user.id, group_id: @group.id) if user_group.save flash[:notice] = I18n.t('admin.trestle.flash.successfully_joined_group') else flash[:alert] = I18n.t('admin.trestle.flash.could_not_join_group') end end redirect_to group_path(@group) end end
9. 9 class User < ApplicationRecord MAX_NUMBER_OF_GROUPS = 10 has_many :user_groups has_many :groups, through: :user_groups def is_old_enough_to_join_group?(group) age > group.minimum_age end def is_group_limit_reached? groups.count >= MAX_NUMBER_OF_GROUPS end end
10. © 2017 InspiraSign - Template All rights reserved 10 “But what if there was a way to have both skinny models AND skinny controllers?!”
11. 11 Robert Martin Clean Code
12. 12 Independent of Frameworks
13. 13 Testable
14. 14 Independent of UI
15. 15 Independent of Database
16. 16 Independent of any external agency
17. 17 https://8thlight.com/blog/uncle-bob/2012/08/13/the-clean-architecture.html
18. 18 Use Cases
19. 19 CreateUser Name Format Name Minimum 2 characters maximum 50 characters. Email Must have valid format as in the example: email@example.com. Password At least 6 characters, maximum 15 characters. Password Confirmation Must be filled in identically to the password. Main Flow - Set of steps Exception Flow - What happened when things do not go well
20. 20 Interactor
21. 21 Interactors Entity Entity Business rules
22. 22 Rails architecture by Uncle Bob
23. 23 Code Samples
24. 24 Example 1
25. 25 Boundary
26. 26 UseCase
27. 27 Example 2
32. 32 Tell-don’t-ask
35. 35 Example 3
37. 37 Other examples
38. 38 TrailBlazer
41. 41 RetroMocha/Obvious
46. 46 Gem Interactor
51. 51 Better
52. 52 class UserGroupsController def create result = AddUserToGroup.call group: @group, user: current_user message = result.message if result.success? flash[:notice] = message else flash[:alert] = message end redirect_to group_path(@group) end end
53. 53 class AddUserToGroup include Interactor def call fail! message: I18n.t('admin.trestle.flash.too_young') unless is_old_enough_to_join_group? fail! message: I18n.t('admin.trestle.flash.too_many_groups') unless group_limit_reached? if create_new_user_group context[:message] = I18n.t('admin.trestle.flash.successfully_joined_group') else fail! message: I18n.t('admin.trestle.flash.could_not_join_group') end end private def group_limit_reached? context[:user].groups.count >= User::MAX_NUMBER_OF_GROUPS end def is_old_enough_to_join_group? context[:user].age >= context[:group].minimum_age end def create_new_user_group context[:user_group] = UserGroup.new(user_id: context[:user].id, group_id: context[:group].id) context[:user_group].save end end
54. result = AddUserToGroup.call group: @group, user: current_user puts result.user_group => #<UserGroup id: 1, user_id: 1, group_id: 1> puts result.message => You have successfully joined the Example group!
55. 55 “But… More Lines of Code?!”
56. “Many Ruby/Rails developers married to Rails " 56
57. 57 Thank you! @patricialuzbast
 patybastos