Rails hurts, because we're using it wrong. Let's fix that!

Transcript

1. RAILS HURTS Ivan Nemytchenko @inemation railshurts.com LET’S FIX THAT!
2. ABOUT ME - first Rails project in 2006 - freelancing, agencies, conferences - former GitLab developer advocate - teaching junior developers at goodprogrammer.ru - online internships for rubyists, Skillgrid virtual agency - live in Serbia
3. RAILSHURTS.COM/CURRENT_STATE
4. RAILSHURTS.COM
5. THE LIFECYCLE OF RAILS DEVELOPER
6. PHASE 1 - RAILS WAY DISCIPLE RailsHurts.com/_lifecycle
7. RailsHurts.com/_lifecycle
8. RailsHurts.com/_lifecycle
9. RailsHurts.com/_lifecycle
10. - 6 years old Rails project - 250 models ~ 100 associations in User model - user base: 165000 leaners - 1-2 active developers KIRILL MOKEVNIN CTO of hexlet.io
14. THE RAILS WAY LET’S INVESTIGATE
15. REQUIREMENTS
16. IMPLEMENTATION class Person < ApplicationRecord validates_presence_of :username, :email, :address validates_confirmation_of :email validates_acceptance_of :terms_of_service geocoded_by :address before_save :geocode end
17. REQUIREMENTS 1. Edit profile 2. Downcase username 3. Set default color 4. Moderation mode
18. IMPLEMENTATION class Person < ApplicationRecord attr_accessor :moderation_mode validates_presence_of :username, :email, :address validates_confirmation_of :email, on: :create validates_acceptance_of :terms_of_service, on: :create validates_presence_of :profession, :workplace if: :in_moderation_mode? geocoded_by :address before_save :geocode, on: :create before_validation :strip_and_downcase_username, on: :create before_validation :set_default_color_theme, on: :create def in_moderation_mode? !!moderation_mode end def strip_and_downcase_username; end def set_default_color_theme; end end
19. REQUIREMENTS 1. Add “create organization” checkbox
20. IMPLEMENTATION class Person < ApplicationRecord attr_accessor :create_an_organization attr_accessor :moderation_mode belongs_to :organization #... after_save :create_default_organization if: :create_organization? def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end def in_moderation_mode? !!moderation_mode end def create_organization? !!create_an_organization end def strip_and_downcase_username; end def set_default_color_theme; end end
21. class Person < ApplicationRecord attr_accessor :create_an_organization attr_accessor :moderation_mode belongs_to :organization validates_presence_of :username, :email, :address validates_confirmation_of :email, on: :create validates_acceptance_of :terms_of_service, on: :create validates_presence_of :profession, :workplace if: :in_moderation_mode? geocoded_by :address before_save :geocode, on: :create before_validation :strip_and_downcase_username, on: :create before_validation :set_default_color_theme, on: :create after_save :create_default_organization if: :create_organization? def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end def in_moderation_mode? !!moderation_mode end def create_organization? !!create_an_organization end def strip_and_downcase_username; end def set_default_color_theme; end end
22. FOUR DIFFERENT SCENARIOS 1. User signs up 2. User updates profile 3. Moderator creates user 4. Moderator updates user
23. FOUR DIFFERENT SCENARIOS strip_and_downcase_username x x set_default_color_theme x validates_presence_of(:username, :email, :address) x x x x validates_confirmation_of(:email) x x validates_acceptance_of(terms_of_service) x x validates_presence_of(:profession, :workspace) x x geocode x x save x x x x create_organization x x Create Update Moderation Create Update
24. class Person < ApplicationRecord attr_accessor :create_an_organization attr_accessor :moderation_mode belongs_to :organization validates_presence_of :username, :email, :address validates_confirmation_of :email, on: :create validates_acceptance_of :terms_of_service, on: :create validates_presence_of :profession, :workplace if: :in_moderation_mode? geocoded_by :address before_save :geocode, on: :create before_validation :strip_and_downcase_username, on: :create before_validation :set_default_color_theme, on: :create after_save :create_default_organization if: :create_organization? def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end def in_moderation_mode? !!moderation_mode end def create_organization? !!create_an_organization end def strip_and_downcase_username; end def set_default_color_theme; end end FOUR DIFFERENT SCENARIOS
25. CODECLIMATE EXPERIMENT RailsHurts.com/_cce
26. PERSON.SAVE IN PSEUDOCODE def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validate(:email, :tos) if create? validate(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end
27. CODECLIMATE EXPERIMENT
28. RailsHurts.com/_osm
29. OUR DECISION MAKING PROCESS (picture idea by @ryanbigg)
30. A LONER METHOD IN PERSON MODEL class Person < ApplicationRecord after_save :create_default_organization if: :create_organization? def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end
31. A CROWD OF LONER METHODS
32. (picture by @benorama)
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37. class CreditRequest def initialize @age = 0 @sex = 0 @income = 0 @credit_history = 0 @requested_amount = 0 @sum = 0 end def calculate #... end def result #... end end SIMPLE TASK
38. class CreditRequest def initialize @age = 0 @sex = 0 @income = 0 @credit_history = 0 @requested_amount = 0 @sum = 0 end def calculate #... end def result #... end end def calculate(age, sex, income, credit_history, requested_amount) sum = 0 if(age >= 21 && age <= 40) sum += 10 elsif(age > 40) sum += 20 end if(sex == "w") sum += 10 end if(income >= 20001 && income <= 40000) sum += 10 elsif(income > 40000) sum += 20 end if(credit_history == "y") sum += 20 end if(requested_amount < 20000) sum += 20 elsif(requested_amount > 20000 && requested_amount <= 40000) sum += 10 end @sum = sum end SIMPLE TASK
39. class CreditRequest def initialize #... end def calculate(age, sex, income, credit_history, requested_amount) #… end def result if(@sum >= 50) puts "Credit request approved" else puts "Credit request declined" end end end SIMPLE TASK
40. class CreditRequest def initialize #... end def calculate(age, sex, income, credit_history, requested_amount) #… end def result if(@sum >= 50) STDOUT.puts "Credit request approved" else STDOUT.puts "Credit request declined" end end end SIMPLE TASK
41. SIMPLE TASK class CreditRequest def initialize #... end def calculate(age, sex, income, credit_history, requested_amount) #… end def result if(@sum >= 50) STDOUT.puts "Credit request approved" else STDOUT.puts "Credit request declined" end end end
42. LAYERED ARCHITECTURE RailsHurts.com/_mfs
43. LAYERED ARCHITECTURE
44. Service encapsulates single process of our business. They take all collaborators (database, logging, external adapters like Facebook, user parameters) and performs a given process. SERVICES
45. KNOWLEDGE DIRECTION
46. KNOWLEDGE DIRECTION
47. CALL SERVICE FROM A MODEL class User < ApplicationRecord has_many :trainings def create_training(params) CreateTrainingService.call(params, self) end end
48. GEMS DO THAT TOO
49. CURRENT USER IN MODELS
50. MODULARITY MODULARITY IS THE LACK OF CIRCULAR DEPENDENCIES
51. class Person < ApplicationRecord def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validates_presence_of(:username, :email, :address) validates_confirmation_of(:email) if create? validates_acceptance_of(terms_of_service) if create? validates_presence_of(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end
52. class Person < ApplicationRecord def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validates_presence_of(:username, :email, :address) validates_confirmation_of(:email) if create? validates_acceptance_of(terms_of_service) if create? validates_presence_of(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end APPLICATION-LOGIC VALIDATIONS
53. APPLICATION LOGIC VS BUSINESS LOGIC
54. class Person < ApplicationRecord def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validates_presence_of(:username, :email, :address) validates_confirmation_of(:email) if create? validates_acceptance_of(terms_of_service) if create? validates_presence_of(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end INTERACTION WITH EXTERNAL SERVICE
55. class Person < ApplicationRecord def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validates_presence_of(:username, :email, :address) validates_confirmation_of(:email) if create? validates_acceptance_of(terms_of_service) if create? validates_presence_of(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end COMPLEX INTERACTION WITH OTHER MODEL(S)
56. class Person < ApplicationRecord def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validates_presence_of(:username, :email, :address) validates_confirmation_of(:email) if create? validates_acceptance_of(terms_of_service) if create? validates_presence_of(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end DATA FILTERING
57. class Person < ApplicationRecord def save_object strip_and_downcase_username if create? set_default_color_theme if create? && !in_moderation_mode? validates_presence_of(:username, :email, :address) validates_confirmation_of(:email) if create? validates_acceptance_of(terms_of_service) if create? validates_presence_of(:profession, :workspace) if in_moderation_mode? geocode if create? save create_organization if create? && create_organization? end def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end end SETTING DEFAULT VALUE
58. DOMAIN MODELS LET’S TALK ABOUT
60. NOT A DOMAIN MODEL class Person < ApplicationRecord attr_accessor :create_an_organization attr_accessor :moderation_mode belongs_to :organization validates_presence_of :username, :email, :address validates_confirmation_of :email, on: :create validates_acceptance_of :terms_of_service, on: :create validates_presence_of :profession, :workplace if: :in_moderation_mode? geocoded_by :address before_save :geocode, on: :create before_validation :strip_and_downcase_username, on: :create before_validation :set_default_color_theme, on: :create after_save :create_default_organization if: :create_organization? def create_default_organization Organization.create(address: address, title: "#{username}'s organization", person: self) end def in_moderation_mode? !!moderation_mode end def create_organization? !!create_an_organization end def strip_and_downcase_username; end def set_default_color_theme; end end
61. 1. EXTRACT SERVICE class Person < ApplicationRecord DEFAULT_COLOR = "#fcaa84" belongs_to :organization validates_presence_of :username, :email, :address end class PersonService def create(params) lat, lng = Geocoder.coordinates(params[:address]) username = params[:username].strip.downcase color = params[:color] || Person::DEFAULT_COLOR prepared_params = params.merge(lat: lat, lng: lng, color: color, username: username) person = Person.create(prepared_params) end end
62. 2. EXTRACT FORM class PersonRegistrationForm < Person include ApplicationPhorm validates_confirmation_of :email validates_acceptance_of :terms_of_service end class PeopleController < ApplicationController def create p = PersonRegistrationForm.new(person_params) if p.valid? PersonService.create(person_params) redirect_to p else render :new end end end
63. 3. HANDLE “CREATE ORGANIZATION” SCENARIO class PersonService def create(params) lat, long = Geocoder.coordinates(params[:address]) username = params[:username].strip.downcase color = params[:color] || Person::DEFAULT_COLOR prepared_params = params.merge(lat: lat, lng: long, color: color, username: username) person = Person.create(prepared_params).save! OrganizationMutator.create_deafult(person) if params[:create_an_organization] end end class OrganizationMutator def create_default(person) Organization.create(address: person.address, title: "#{person.username}'s organization", person: person) end end
64. 3. INTRODUCE PERSON MUTATOR class PersonMutator def create(params) username = params[:username].strip.downcase color = params[:color] || Person::DEFAULT_COLOR prepared_params = params.merge(color: color, username: username) person = Person.create(prepared_params).save! person end end class PersonService def create(params) lat, lng = Geocoder.coordinates(params[:address]) person = PersonMutator.create(params.merge(lat: lat, lng: lng)).save! OrganizationMutator.create(person) if params[:create_an_organization] end end
65. 4. UPDATE IS TRIVIAL class PeopleController < ApplicationController def update p = Person.find(params[:id]) if p.valid? p.update(person_params) redirect_to p else render :new end end end
66. 5. MODERATION class ModerationPersonRegistrationForm < Person include ApplicationPhorm validates_confirmation_of :email validates_acceptance_of :terms_of_service validates_presence_of :profession, :workplace end def create p = ModerationPersonRegistrationForm.new(person_params) if p.valid? PersonService.create(person_params) redirect_to p else render :new end end def update p = ModerationPersonRegistrationForm.find(params[:id]) if p.valid? p.update(person_params) redirect_to p else render :new end end
67. LAYERED ARCHITECTURE
68. Models treat them as domain models, they contain relations and business rules Mutators to handle creation/editing/deletion logic (so that we always operate with objects in correct state) Services to handle business operations logic and interaction with external services Form objects application logic, use-case validation specific rules, defaults and filters THE PURPOSE OF LAYERS
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71. Lazy man CQRS queres - scopes, commands - mutators Flexibility in controllers use models, mutators or services Services and mutators are just functions! NICE THINGS ABOUT THIS ARCHITECTURE
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74. FINAL PART
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79. DHH: ``I’ve described this discovery of Ruby in the past as finding a magical glove that just fit my brain perfectly. Better than I had ever imagined any glove could ever fit`` rubyonrails.org/doctrine
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81. RUBY GOTO STATEMENT
82. Rails needs a stronger voice of the community!
83. MAKE RAILS GREAT AGAIN! railshurts.com/book @railshurts, @inemation - GitLab stickers - GitLab power banks (show me your code) - I’ll be in Kiev until June 7