Do You Need That Validation? Let Me Call You Back About It

Rails apps start nice and cute. Fast forward a year and business logic and view logic are entangled in our validations and callbacks - getting in our way at every turn. Wasn’t this supposed to be easy?

Let’s explore different approaches to improve the situation and untangle the web.

Transcript

1. Thanks for making it!
   

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2. The magic hook
   

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3. Event Form
   

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4. Repetitive
   

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5. Much better!
   

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6. class Event < ApplicationRecord
   before_validation :set_datetimes_to_date
   def set_datetimes_to_date
   base_date = date.to_datetime
   DATE_TIME_FIELDS.each do |time_attribute|
   original = public_send(time_attribute)
   if original
   adjusted_time =
   base_date.change hour: original.hour,
   min: original.min
   self.public_send("#{time_attribute}=", adjusted_time)
   end
   end
   end
   end
   

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7. class Event < ApplicationRecord
   before_validation :set_datetimes_to_date
   def set_datetimes_to_date
   base_date = date.to_datetime
   DATE_TIME_FIELDS.each do |time_attribute|
   original = public_send(time_attribute)
   if original
   adjusted_time =
   base_date.change hour: original.hour,
   min: original.min
   self.public_send("#{time_attribute}=", adjusted_time)
   end
   end
   end
   end
   

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8. class Event < ApplicationRecord
   before_validation :set_datetimes_to_date
   def set_datetimes_to_date
   base_date = date.to_datetime
   DATE_TIME_FIELDS.each do |time_attribute|
   original = public_send(time_attribute)
   if original
   adjusted_time =
   base_date.change hour: original.hour,
   min: original.min
   self.public_send("#{time_attribute}=", adjusted_time)
   end
   end
   end
   end
   

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9. class Event < ApplicationRecord
   before_validation :set_datetimes_to_date
   def set_datetimes_to_date
   base_date = date.to_datetime
   DATE_TIME_FIELDS.each do |time_attribute|
   original = public_send(time_attribute)
   if original
   adjusted_time =
   base_date.change hour: original.hour,
   min: original.min
   self.public_send("#{time_attribute}=", adjusted_time)
   end
   end
   end
   end
   Datetime fields
   

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10. class Event < ApplicationRecord
    before_validation :set_datetimes_to_date
    def set_datetimes_to_date
    base_date = date.to_datetime
    DATE_TIME_FIELDS.each do |time_attribute|
    original = public_send(time_attribute)
    if original
    adjusted_time =
    base_date.change hour: original.hour,
    min: original.min
    self.public_send("#{time_attribute}=", adjusted_time)
    end
    end
    end
    end
    

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11. class Event < ApplicationRecord
    before_validation :set_datetimes_to_date
    def set_datetimes_to_date
    base_date = date.to_datetime
    DATE_TIME_FIELDS.each do |time_attribute|
    original = public_send(time_attribute)
    if original
    adjusted_time =
    base_date.change hour: original.hour,
    min: original.min
    self.public_send("#{time_attribute}=", adjusted_time)
    end
    end
    end
    end
    

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12. class Event < ApplicationRecord
    before_validation :set_datetimes_to_date
    def set_datetimes_to_date
    base_date = date.to_datetime
    DATE_TIME_FIELDS.each do |time_attribute|
    original = public_send(time_attribute)
    if original
    adjusted_time =
    base_date.change hour: original.hour,
    min: original.min
    self.public_send("#{time_attribute}=", adjusted_time)
    end
    end
    end
    end
    

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13. event =
    Event.new(
    name: "Ruby On Ice",
    location: "Tegernsee",
    date: "24.02.2019",
    crew_arrives_at: "6:45",
    performers_arrive_at: "9:30",
    open_at: "9:30",
    starts_at: "10:00",
    ends_at: "16:00"
    )
    event.valid?
    

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14. #name: "Ruby On Ice",
    location: "Tegernsee",
    date: Sun, 24 Feb 2019,
    crew_arrives_at: Sun, 24 Feb 2019 6:45:00,
    performers_arrive_at: Sun, 24 Feb 2019 9:00:00,
    open_at: Sun, 24 Feb 2019 9:00:00,
    starts_at: Sun, 24 Feb 2019 9:30:00,
    ends_at: Sun, 24 Feb 2019 20:00:00>
    It works!
    

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16. let(:event) do
    build :event,
    ends_at: Time.zone.local(2042, 1, 1, 15, 45)
    end
    

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17. let(:event) do
    build :event,
    ends_at: Time.zone.local(2042, 1, 1, 15, 45)
    end
    

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18. let(:event) do
    build :event,
    ends_at: Time.zone.local(2042, 1, 1, 15, 45)
    end
    it "works" do
    p event.ends_at # Wed, 01 Jan 2042 15:45:00
    event.save!
    p event.ends_at # Sun, 24 Feb 2019 15:45:00
    end
    Have fun debugging!
    

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20. let(:event) do
    create :event,
    ends_at: Time.zone.local(2042, 1, 1, 15, 45)
    end
    it "retrieves the right events" do
    query = FutureEvents.new
    expect(query.call(23.years)).to include(event)
    end
    Have fun debugging!
    

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21. class Event < ApplicationRecord
    before_validation :set_datetimes_to_date
    def set_datetimes_to_date
    base_date = date.to_datetime
    DATE_TIME_FIELDS.each do |time_attribute|
    original = public_send(time_attribute)
    if original
    adjusted_time =
    base_date.change hour: original.hour,
    min: original.min
    self.public_send("#{time_attribute}=", adjusted_time)
    end
    end
    end
    end
    

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22. class Event < ApplicationRecord
    before_validation :set_datetimes_to_date
    def set_datetimes_to_date
    base_date = date.to_datetime
    DATE_TIME_FIELDS.each do |time_attribute|
    original = public_send(time_attribute)
    if original
    adjusted_time =
    base_date.change hour: original.hour,
    min: original.min
    self.public_send("#{time_attribute}=", adjusted_time)
    end
    end
    end
    end
    Smell
    

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23. class Event < ApplicationRecord
    before_validation :set_datetimes_to_date
    def set_datetimes_to_date
    base_date = date.to_datetime
    DATE_TIME_FIELDS.each do |time_attribute|
    original = public_send(time_attribute)
    if original
    adjusted_time =
    base_date.change hour: original.hour,
    min: original.min
    self.public_send("#{time_attribute}=", adjusted_time)
    end
    end
    end
    end
    Why does the model clean up
    

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24. Validations
    

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25. validate :unique_email, if: :email_changed?
    validate :owns_notification_email,
    if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    gitlab/user
    

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26. validate :unique_email, if: :email_changed?
    validate :owns_notification_email,
    if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    gitlab/user
    

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27. Why the effort?
    

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28. Practice open?
    

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29. Practice open?
    No overlap?
    

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30. Practice open?
    No overlap?
    Right skills?
    

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31. Practice open?
    No overlap?
    Right skills?
    Patient can be contacted?
    

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32. Practice open?
    No overlap?
    Right skills?
    Patient can be contacted?
    Associated models
    

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33. Practice open?
    No overlap?
    Right skills?
    Patient can be contacted?
    Associated models
    ...
    

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34. Expensive Test Setup
    

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35. validate :unique_email, if: :email_changed?
    validate :owns_notification_email, if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    before_validation :set_notification_email, if: :new_record?
    before_validation :set_public_email, if: :public_email_changed?
    before_validation :set_commit_email, if: :commit_email_changed?
    # in case validation is skipped
    before_save :set_public_email, if: :public_email_changed?
    # in case validation is skipped
    before_save :set_commit_email, if: :commit_email_changed?
    before_save :skip_reconfirmation!, if: #>(user) {
    user.email_changed? #& user.read_only_attribute?(:email)
    }
    before_save :check_for_verified_email, if: #>(user) {
    user.email_changed? #& !user.new_record?
    }
    gitlab/user
    

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36. validate :unique_email, if: :email_changed?
    validate :owns_notification_email, if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    before_validation :set_notification_email, if: :new_record?
    before_validation :set_public_email, if: :public_email_changed?
    before_validation :set_commit_email, if: :commit_email_changed?
    # in case validation is skipped
    before_save :set_public_email, if: :public_email_changed?
    # in case validation is skipped
    before_save :set_commit_email, if: :commit_email_changed?
    before_save :skip_reconfirmation!, if: #>(user) {
    user.email_changed? #& user.read_only_attribute?(:email)
    }
    before_save :check_for_verified_email, if: #>(user) {
    user.email_changed? #& !user.new_record?
    }
    gitlab/user
    

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37. validate :unique_email, if: :email_changed?
    validate :owns_notification_email, if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    before_validation :set_notification_email, if: :new_record?
    before_validation :set_public_email, if: :public_email_changed?
    before_validation :set_commit_email, if: :commit_email_changed?
    # in case validation is skipped
    before_save :set_public_email, if: :public_email_changed?
    # in case validation is skipped
    before_save :set_commit_email, if: :commit_email_changed?
    before_save :skip_reconfirmation!, if: #>(user) {
    user.email_changed? #& user.read_only_attribute?(:email)
    }
    before_save :check_for_verified_email, if: #>(user) {
    user.email_changed? #& !user.new_record?
    }
    Ways to change?
    

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38. validate :unique_email, if: :email_changed?
    validate :owns_notification_email, if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    before_validation :set_notification_email, if: :new_record?
    before_validation :set_public_email, if: :public_email_changed?
    before_validation :set_commit_email, if: :commit_email_changed?
    # in case validation is skipped
    before_save :set_public_email, if: :public_email_changed?
    # in case validation is skipped
    before_save :set_commit_email, if: :commit_email_changed?
    before_save :skip_reconfirmation!, if: #>(user) {
    user.email_changed? #& user.read_only_attribute?(:email)
    }
    before_save :check_for_verified_email, if: #>(user) {
    user.email_changed? #& !user.new_record?
    }
    gitlab/user
    

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39. validate :unique_email, if: :email_changed?
    validate :owns_notification_email, if: :notification_email_changed?
    validate :owns_public_email, if: :public_email_changed?
    validate :owns_commit_email, if: :commit_email_changed?
    before_validation :set_notification_email, if: :new_record?
    before_validation :set_public_email, if: :public_email_changed?
    before_validation :set_commit_email, if: :commit_email_changed?
    # in case validation is skipped
    before_save :set_public_email, if: :public_email_changed?
    # in case validation is skipped
    before_save :set_commit_email, if: :commit_email_changed?
    before_save :skip_reconfirmation!, if: #>(user) {
    user.email_changed? #& user.read_only_attribute?(:email)
    }
    before_save :check_for_verified_email, if: #>(user) {
    user.email_changed? #& !user.new_record?
    }
    gitlab/user
    

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40. Why are we
    doing this?
    

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41. Affordance
    

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42. Wants to be cuddled
    

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43. Wants to be fed
    

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44. class MySolution
    def do_thing(argument)
    end
    end
    OOP Affordance
    

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45. Model
    View
    Controller
    Rails Affordance
    

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46. “Fat Models
    Skinny Controllers”
    

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47. 1 or 2 use cases
    stuck on every model
    

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48. Controllers
    Models
    

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49. Registrations
    User
    

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50. Registrations
    User
    Users
    

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51. Registrations
    User
    Users
    Users ##. ##. ##.
    

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52. Controllers
    Models
    Service Objects
    

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53. Registrations
    User
    Users
    Users ##. ##. ##.
    ##. ##. ##. ##. ##.
    

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54. Registrations
    User
    Users
    Users ##. ##. ##.
    ##. ##. ##. ##. ##.
    Business Logic Separated
    

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55. Registrations
    User
    Users
    Users ##. ##. ##.
    ##. ##. ##. ##. ##.
    Business Logic Separated
    Validations and Callbacks still mixed
    

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56. Registrations
    User
    Users
    Users ##. ##. ##.
    ##. ##. ##. ##. ##.
    Business Logic Separated
    Validations and Callbacks still mixed
    Run all the time by default
    

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57. Registrations
    User
    Users
    Users ##. ##. ##.
    ##. ##. ##. ##. ##.
    SignUp Show
    Index ##. ##. ##.
    

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58. Registrations
    User
    ##.
    SignUp
    View
    Controller
    Service
    Model
    

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59. class User < ApplicationRecord
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    A User Model
    

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60. class User < ApplicationRecord
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    Sign Up / Edit Only
    

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61. class User < ApplicationRecord
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    View Related
    

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62. class User < ApplicationRecord
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    WHWWHHYYY???
    

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63. Registrations
    User
    ##.
    SignUp
    View
    Controller
    Service
    Model
    Knowledge?
    

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64. Registrations
    User
    ##.
    SignUp
    View
    Controller
    Service
    Model
    Why Solve it here?
    

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65. Registrations
    User
    ##.
    SignUp
    View
    Controller
    Service
    Model
    Opt Out
    

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66. View Slide

67. View Slide

68. Registrations
    User
    ##.
    SignUp
    View
    Controller
    Service
    Model
    Could solve here
    

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69. Registrations
    User
    ##.
    SignUp
    View
    Controller
    Service
    Model
    Or here?
    

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70. View Slide

71. Tobi complaining
    about validations
    and callbacks
    You’ve seen:
    

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72. Do You Need That Validation?
    Let Me Call You Back About It
    Tobias Pfeiffer
    @PragTob
    pragtob.info
    

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73. View Slide

74. Specifics clutter Model
    

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75. Specifics clutter Model
    Hard to get overiew
    

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76. Specifics clutter Model
    Hard to get overiew
    Run all the time
    

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77. class User < ApplicationRecord
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    ActiveRecord Original
    

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78. What does Rails offer?
    

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79. module UserRegistration
    extend ActiveSupport#:Concern
    included do
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    end
    end
    Concerns
    

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80. module Copyable
    def copy_to(destination)
    Notification.suppress do
    # Copy logic that creates new
    # comments that we do not want
    # triggering notifications.
    end
    end
    end
    Suppress
    

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81. class Person < ApplicationRecord
    validates :email,
    uniqueness: true,
    on: :account_setup
    validates :age,
    numericality: true,
    on: :account_setup
    end
    Custom Contexts
    

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82. What’s out there?
    

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83. Form Objects
    

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84. Form Objects
    Form Objects
    Form Objects
    class Registration
    include ActiveModel#:Model
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :email, :password
    def save
    if valid?
    user = BaseUser.new(email: email, password_digest: hash_password)
    user.save!
    send_welcome_email
    true
    else
    false
    end
    end
    end
    

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85. Form Objects
    Form Objects
    Plain ActiveModel
    class Registration
    include ActiveModel#:Model
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :email, :password
    def save
    if valid?
    user = BaseUser.new(email: email, password_digest: hash_password)
    user.save!
    send_welcome_email
    true
    else
    false
    end
    end
    end
    

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86. Form Objects
    Form Objects
    Validations
    class Registration
    include ActiveModel#:Model
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :email, :password
    ###.
    end
    

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87. Form Objects
    Form Objects
    Attributes
    class Registration
    include ActiveModel#:Model
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :email, :password
    ###.
    end
    

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88. Form Objects
    Form Objects
    Map to ActiveRecord
    class Registration
    ###.
    def save
    if valid?
    user = BaseUser.new(
    email: email,
    password_digest: hash_password
    )
    user.save!
    send_welcome_email
    true
    else
    false
    end
    end
    

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89. Form Objects
    Form Objects
    Interface
    class Registration
    ###.
    def save
    if valid?
    user = BaseUser.new(
    email: email,
    password_digest: hash_password
    )
    user.save!
    send_welcome_email
    true
    else
    false
    end
    end
    

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90. Form Objects
    Form Objects
    Callbacks
    class Registration
    ###.
    def save
    if valid?
    user = BaseUser.new(
    email: email,
    password_digest: hash_password
    )
    user.save!
    send_welcome_email
    true
    else
    false
    end
    end
    

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91. def create
    @user = Registration.new(registration_params)
    if @user.save
    # ##.
    else
    # ##.
    end
    end
    Same Interface
    

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92. Inheritance!
    

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93. Inheritance!
    class User#:AsSignUp < ActiveType#:Record[User]
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    

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94. Inheritance!
    class User#:AsSignUp < ActiveType#:Record[User]
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    

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95. ActiveType
    class User#:AsSignUp < ActiveType#:Record[User]
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    

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96. class User < ApplicationRecord
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    Original
    

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97. Almost the same!
    class User#:AsSignUp < ActiveType#:Record[User]
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    

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98. Handle STI, Routes etc.
    class User#:AsSignUp < ActiveType#:Record[User]
    validates :email,
    presence: true,
    confirmation: true
    validates :password,
    confirmation: true,
    length: { minimum: 8 }
    validates :terms, acceptance: true
    attr_accessor :password
    before_save :hash_password
    after_commit :send_welcome_email, on: :create
    ###.
    end
    

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99. Changesets
    

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100. Changesets
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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101. Elixir
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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102. Pipe
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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103. Context
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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104. “strong parameters”
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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105. Validations
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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106. callback
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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107. Mixing concerns
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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108. validate :unique_email, if: :email_changed?
     validate :owns_notification_email, if: :notification_email_changed?
     validate :owns_public_email, if: :public_email_changed?
     validate :owns_commit_email, if: :commit_email_changed?
     before_validation :set_notification_email, if: :new_record?
     before_validation :set_public_email, if: :public_email_changed?
     before_validation :set_commit_email, if: :commit_email_changed?
     # in case validation is skipped
     before_save :set_public_email, if: :public_email_changed?
     # in case validation is skipped
     before_save :set_commit_email, if: :commit_email_changed?
     before_save :skip_reconfirmation!, if: #>(user) {
     user.email_changed? #& user.read_only_attribute?(:email)
     }
     before_save :check_for_verified_email, if: #>(user) {
     user.email_changed? #& !user.new_record?
     }
     Remember this?
     

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109. Combinable
     defmodule ValidationShowcase.Accounts.User do
     # ...
     def registration_changeset(user, attrs) do
     user
     |> base_changeset(attrs)
     |> cast(attrs, [:email, :password, :terms_of_service])
     |> validate_required([:email, :password])
     |> validate_confirmation(:email)
     |> validate_confirmation(:password)
     |> validate_length(:password, min: 8)
     |> validate_acceptance(:terms_of_service)
     |> hash_password()
     end
     end
     

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110. defmodule ValidationShowcase.Accounts do
     def create_user(attrs \\ %{}) do
     %User{}
     |> User.registration_changeset(attrs)
     |> Repo.insert()
     |> send_welcome_email()
     end
     end
     Context
     

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111. defmodule ValidationShowcase.Accounts do
     def create_user(attrs \\ %{}) do
     %User{}
     |> User.registration_changeset(attrs)
     |> Repo.insert()
     |> send_welcome_email()
     end
     end
     Changeset
     

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112. defmodule ValidationShowcase.Accounts do
     def create_user(attrs \\ %{}) do
     %User{}
     |> User.registration_changeset(attrs)
     |> Repo.insert()
     |> send_welcome_email()
     end
     end
     “after_commit”
     

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113. defmodule ValidationShowcaseWeb.UserController do
     def create(conn, %{"user" => user_params}) do
     case Accounts.create_user(user_params) do
     {:ok, user} ->
     conn
     |> put_flash(:info, "User created successfully.")
     |> redirect(to: Routes.user_path(conn, :show, user))
     {:error, %Ecto.Changeset{} = changeset} ->
     render(conn, "new.html", changeset: changeset)
     end
     end
     end
     Controller
     

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114. Form Objects
     Form Objects
     Separate Operations and Validators
     

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115. trailblazer
     

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116. class TbRegistrationsController < ApplicationController
     def create
     result = Registration#:Create.(params: params)
     if result.success?
     redirect_to "/users/", notice: 'User was created.'
     else
     @user = result["contract.default"]
     render "users/new"
     end
     end
     end
     

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117. class TbRegistrationsController < ApplicationController
     def create
     result = Registration#:Create.(params: params)
     if result.success?
     redirect_to "/users/", notice: 'User was created.'
     else
     @user = result["contract.default"]
     render "users/new"
     end
     end
     end
     Operation
     

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118. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     

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119. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     Setup Model
     

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120. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     Setup Form Object
     

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121. module Registration#:Contract
     class Create < Reform#:Form
     include Dry
     include Reform#:Form#:ActiveModel
     feature Coercion
     model :tb_registration
     property :email
     property :email_confirmation, virtual: true
     property :password, virtual: true
     property :password_confirmation, virtual: true
     property :terms, virtual: true, type: Types#:Params#:Bool
     validation do
     required(:email).filled.confirmation
     required(:password).value(min_size?: 8).confirmation
     required(:terms).value(:true?)
     end
     end
     end
     

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122. module Registration#:Contract
     class Create < Reform#:Form
     include Dry
     include Reform#:Form#:ActiveModel
     feature Coercion
     model :tb_registration
     property :email
     property :email_confirmation, virtual: true
     property :password, virtual: true
     property :password_confirmation, virtual: true
     property :terms, virtual: true, type: Types#:Params#:Bool
     validation do
     required(:email).filled.confirmation
     required(:password).value(min_size?: 8).confirmation
     required(:terms).value(:true?)
     end
     end
     end
     

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123. module Registration#:Contract
     class Create < Reform#:Form
     property :email
     property :email_confirmation, virtual: true
     property :password, virtual: true
     property :password_confirmation, virtual: true
     property :terms, virtual: true,
     type: Types#:Params#:Bool
     validation do
     required(:email).filled.confirmation
     required(:password).value(min_size?: 8).confirmation
     required(:terms).value(:true?)
     end
     end
     end
     

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124. Attributes
     module Registration#:Contract
     class Create < Reform#:Form
     property :email
     property :email_confirmation, virtual: true
     property :password, virtual: true
     property :password_confirmation, virtual: true
     property :terms, virtual: true,
     type: Types#:Params#:Bool
     validation do
     required(:email).filled.confirmation
     required(:password).value(min_size?: 8).confirmation
     required(:terms).value(:true?)
     end
     end
     end
     

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125. dry-validation
     module Registration#:Contract
     class Create < Reform#:Form
     property :email
     property :email_confirmation, virtual: true
     property :password, virtual: true
     property :password_confirmation, virtual: true
     property :terms, virtual: true,
     type: Types#:Params#:Bool
     validation do
     required(:email).filled.confirmation
     required(:password).value(min_size#: 8).confirmation
     required(:terms).value(:true?)
     end
     end
     end
     

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126. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     validate
     

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127. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     Callback
     

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128. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     Persist
     

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129. class Registration#:Create < Trailblazer#:Operation
     step Model(BaseUser, :new)
     step Contract#:Build(
     constant: Registration#:Contract#:Create
     )
     step Contract#:Validate(key: :tb_registration)
     step :hash_password
     step Contract#:Persist()
     step :send_welcome_email
     end
     Callback
     

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130. “Models are persistence-only and
     solely define associations and
     scopes. No business code is to be
     found here. No validations, no
     callbacks.”
     trailblazer
     

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131. The architecture eases keeping the
     business logic (entities) separated
     from details such as persistence or
     validations.
     hanami/model
     

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132. Takeaway
     

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133. I don’t hate Rails
     

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134. I don’t hate Rails
     Future in Rails?
     

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135. I don’t hate Rails
     Affordances
     Future in Rails?
     

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136. I don’t hate Rails
     Alternatives
     Affordances
     Future in Rails?
     

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137. Form Objects
     

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138. Inheritance!
     

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139. Changesets
     

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140. Form Objects
     Form Objects
     Separate Operations and Validators
     

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141. I don’t hate Rails
     Careful with validations and callbacks
     Alternatives
     Affordances
     Future in Rails?
     

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142. Thank you!
     

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