Architecture of hanami applications

The general part of any web application is business logic. Unforchanotly, it's really hard to find a framework with specific rules and explanations how to work with it. In hanami, we care about long-term maintenance that's why it's really important to us how to work with business logic.

In my talk, I'll share my ideas how to store and work with business logic in hanami apps. We will talk about hanami, dry and some architecture ideas, like event sourcing. This talk will be interesting for any developers. If you work with other frameworks you can take these ideas and my it to your project.

Transcript

1. -> mail@davydovanton.com
   title: RubyKaigi2k18
   

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2. ❤

   

   Hello Japan!

   

   ❤
   

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3. What have I learned here?
   

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4. Is ramen still awesome?
   

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5. View Slide

6. Is Java more popular
   than ruby?
   

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8. Is Ruby still dying?
   

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9. View Slide

10. Is RubyKaigi still
    awesome?
    

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11. View Slide

12. ❤

    

    Hello RubyKaigi!

    

    ❤
    

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13. Anton Davydov
    github.com/davydovanton

    twitter.com/anton_davydov
    davydovanton.com
    

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14. View Slide

15. Stickers
    

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16. View Slide

17. ~200 slides
    

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18. -> mail@davydovanton.com
    title: RubyKaigi2k18
    

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19. Architecture
    

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20. View Slide

21. Why?
    

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22. Trying to unify architecture
    ideas for hanami projects
    

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23. Getting feedback
    

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24. Problems
    

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25. Management
    Performance
    Maintenance
    

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26. Management
    Performance
    Maintenance
    

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27. Clean code
    Good architecture
    Maintainable product
    Pretty code
    

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28. Clean code
    Good architecture
    Maintainable product
    Pretty code
    biased
    view
    

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29. What do we really
    want?
    

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30. To add new features
    

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31. Isolation
    Sequential logic
    No global state
    

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32. Delete (refactoring)
    old code
    

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33. Isolation
    Test coverage
    

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34. Conclusions
    

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35. Isolation
    Sequential logic
    No global state

    Test coverage
    

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36. But we live in a real
    world
    

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37. class InstitutionsController < ApplicationController
    load_and_authorize_resource :only => [:destroy,:edit,:new,:create,:update]
    before_filter :authenticate_user!, :except =>
    [:student_registration, :show, :validate_registration_pin, :result, :admission, :buy_registration_pin,:paygate_callback_failure, :paygate_cancel, :paygate_pending, :paygate_callback_success, :pi
    nsaction_info_print]
    before_filter :find_institution, :except =>
    [:show,:index, :new, :create, :semesters_for_institute_type, :start_end_date_for_assessment_period, :courses_for_batch, :paygate_callback_failure, :paygate_cancel, :paygate_pending, :paygate_cal
    _success, :pin_transaction_info_print]
    before_filter :add_bread_crumb,:except => [:show]
    def paygate_callback_success
    @pay_gate_config = YAML::load(File.open("#{Rails.root}/config/pay_gate_config.yml"))[Rails.env]
    @payment = TransactionRecord.find_by_order_number(params[:OrderID])
    uri = URI("https://fidelitypaygate.fidelitybankplc.com/cipg/MerchantServices/UpayTransactionStatus.ashx")
    parameters = {:MERCHANT_ID => "#{@pay_gate_config['merchant_id']}", :ORDER_ID => "#{@payment.order_number}"}
    uri.query = URI.encode_www_form(parameters)
    result =open(uri).read
    result_hash = Hash.from_xml(result)
    record_payment_details(result_hash)
    if result_hash["CIPG"]["StatusCode"] == PaymentRecord::PAYMENT_SUCCESS_CODE
    if @payment.transactionable_type.eql?("PaymentRecord")
    redirect_to institution_fees_path(@payment.transactionable_type.fee.institution), :notice => "Payment transaction has been #{result_hash['CIPG']['Status']}"
    elsif @payment.transactionable_type.eql?("PinBuyerInfo")
    unless @payment.transactionable.pin_id.present?
    @registration = @payment.transactionable.registration
    @valid_registration_pin_groups = @registration.valid_registration_pin_groups
    @online_valid_registration_pin_groups = @valid_registration_pin_groups.where(:pin_available_type => 'Online')
    @offline_valid_registration_pin_groups = @valid_registration_pin_groups.where(:pin_available_type => 'Offline')
    @available_pin = nil
    @online_valid_registration_pin_groups.each do |vpg|
    if vpg.available_pins.present?
    @available_pin = vpg.available_pins.first
    break
    else
    next
    end
    end
    if !@available_pin.present?
    @offline_valid_registration_pin_groups.each do |vpg|
    if vpg.available_pins.present?
    @available_pin = vpg.available_pins.first
    break
    else
    next
    end
    end
    end
    if @available_pin.present?
    @payment.transactionable.pin_id = @available_pin.id
    @payment.transactionable.save
    @available_pin.is_available = false
    @available_pin.save
    @available_pin.reload
    if @available_pin.pin_group.pin_available_type == 'Offline'
    @message = "Your Order Number is #{@payment.order_number}. Please Print Transaction report to claim you PIN from Institution."
    else
    @assigned_pin = @available_pin.number
    @message = "Your PIN is #{@assigned_pin}. Please keep this PIN secret."
    end
    else
    @message = "No pin available for #{@registration.name}. Your order number is #{@payment.order_number}.Please contact with institution to get your money back if you have paid."
    end
    else
    pin = Pin.find @payment.transactionable.pin_id
    if(pin.present? && pin.pin_group.pin_available_type == 'Offline')
    @message = "Your Order Number is #{@payment.order_number}. Please Print Transaction report to claim you PIN from Institution."
    else
    @available_pin = Pin.find @payment.transactionable.pin_id
    @assigned_pin = @available_pin.number
    @message = "Your PIN is #{ @assigned_pin}. Please keep this PIN secret."
    

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38. How can we improve
    the situation?
    

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40. Abstraction
    Actions
    

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41. class InstitutionsController < ApplicationController
    load_and_authorize_resource :only => [:destroy,:edit,:new,:create,:update]
    before_filter :authenticate_user!, :except =>
    [:student_registration, :show, :validate_registration_pin, :result, :admission, :buy_registration_pin,:paygate_callback_failure, :paygate_cancel, :paygate_pending, :paygate_callback_success, :pi
    nsaction_info_print]
    before_filter :find_institution, :except =>
    [:show,:index, :new, :create, :semesters_for_institute_type, :start_end_date_for_assessment_period, :courses_for_batch, :paygate_callback_failure, :paygate_cancel, :paygate_pending, :paygate_cal
    _success, :pin_transaction_info_print]
    before_filter :add_bread_crumb,:except => [:show]
    def paygate_callback_success
    @pay_gate_config = YAML::load(File.open("#{Rails.root}/config/pay_gate_config.yml"))[Rails.env]
    @payment = TransactionRecord.find_by_order_number(params[:OrderID])
    uri = URI("https://fidelitypaygate.fidelitybankplc.com/cipg/MerchantServices/UpayTransactionStatus.ashx")
    parameters = {:MERCHANT_ID => "#{@pay_gate_config['merchant_id']}", :ORDER_ID => "#{@payment.order_number}"}
    uri.query = URI.encode_www_form(parameters)
    result =open(uri).read
    result_hash = Hash.from_xml(result)
    record_payment_details(result_hash)
    if result_hash["CIPG"]["StatusCode"] == PaymentRecord::PAYMENT_SUCCESS_CODE
    if @payment.transactionable_type.eql?("PaymentRecord")
    redirect_to institution_fees_path(@payment.transactionable_type.fee.institution), :notice => "Payment transaction has been #{result_hash['CIPG']['Status']}"
    elsif @payment.transactionable_type.eql?("PinBuyerInfo")
    unless @payment.transactionable.pin_id.present?
    @registration = @payment.transactionable.registration
    @valid_registration_pin_groups = @registration.valid_registration_pin_groups
    @online_valid_registration_pin_groups = @valid_registration_pin_groups.where(:pin_available_type => 'Online')
    @offline_valid_registration_pin_groups = @valid_registration_pin_groups.where(:pin_available_type => 'Offline')
    @available_pin = nil
    @online_valid_registration_pin_groups.each do |vpg|
    if vpg.available_pins.present?
    @available_pin = vpg.available_pins.first
    break
    else
    next
    end
    end
    if !@available_pin.present?
    @offline_valid_registration_pin_groups.each do |vpg|
    if vpg.available_pins.present?
    @available_pin = vpg.available_pins.first
    break
    else
    next
    end
    end
    end
    if @available_pin.present?
    @payment.transactionable.pin_id = @available_pin.id
    @payment.transactionable.save
    @available_pin.is_available = false
    @available_pin.save
    @available_pin.reload
    if @available_pin.pin_group.pin_available_type == 'Offline'
    @message = "Your Order Number is #{@payment.order_number}. Please Print Transaction report to claim you PIN from Institution."
    else
    @assigned_pin = @available_pin.number
    @message = "Your PIN is #{@assigned_pin}. Please keep this PIN secret."
    end
    else
    @message = "No pin available for #{@registration.name}. Your order number is #{@payment.order_number}.Please contact with institution to get your money back if you have paid."
    end
    else
    pin = Pin.find @payment.transactionable.pin_id
    if(pin.present? && pin.pin_group.pin_available_type == 'Offline')
    @message = "Your Order Number is #{@payment.order_number}. Please Print Transaction report to claim you PIN from Institution."
    else
    @available_pin = Pin.find @payment.transactionable.pin_id
    @assigned_pin = @available_pin.number
    

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42. MVC
    V and C MVC
    

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43. Solutions?
    

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44. Abstraction
    Functional (callable)
    objects
    

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45. Services
    Interactors
    dry-transactions
    dry-monads (DO notations)
    Operations
    Etc.
    

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46. func_object = FuncObject.new
    func_object.call(params)
    # => result object with state
    

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47. func_object = FuncObject.new
    func_object.call(params)
    # => result object with state
    

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48. func_object = FuncObject.new
    func_object.call(params)
    # => result object
    

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49. Isolation
    

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50. def call(params)
    result = FuncObject.new.call(params)
    if result.successful?
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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51. def call(params)
    result = FuncObject.new.call(params)
    if result.successful?
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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52. def call(params)
    result = FuncObject.new.call(params)
    if result.successful?
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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53. Logic sequence
    

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54. class Create
    include Dry::Transaction
    include Dry::Matcher
    Dry::Validation.load_extensions(:monads)
    VALIDATOR = Dry::Validation.JSON do
    # ...
    end
    step :extract
    step :validate
    step :create
    

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55. class Create
    include Dry::Transaction
    include Dry::Matcher
    Dry::Validation.load_extensions(:monads)
    VALIDATOR = Dry::Validation.JSON do
    # ...
    end
    step :extract
    step :validate
    step :create
    

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56. class Interactor
    def call(payload)
    data = yield extract!(payload)
    entity = yield validate!(data)
    create!(entity)
    end
    # …
    end
    

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57. class Interactor
    def call(payload)
    extract!
    validate!
    create!
    end
    # …
    end
    

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58. No global state
    

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59. def call(params)
    result = FuncObject.new.call(params)
    if result.successful?
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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60. Easy testing
    

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61. def initialize(object: FuncObject.new)
    @object = object
    end
    def call(params)
    result = @object.call(params)
    if result.successful?
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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62. def initialize(object: FuncObject.new)
    @object = object
    end
    def call(params)
    result = @object.call(params)
    if result.successful?
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    Dependency Injection ❤
    

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63. let(:action) { Create.new(object: SuccessObject.new) }
    it { expect(action.call(params).to eq ... }

    

    let(:action) { Create.new(object: FailedObject.new) }
    it { expect(action.call(params).to eq ... }
    

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64. let(:other_object) { -> (_) { nil } }

    let(:object) { Create.new(object: other_object) }
    it { expect(action.call(params).to eq ... }
    

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65. Objects can call
    other objects
    

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66. Actions Interactors Libs
    Objects
    (public) (private)
    

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67. Problems
    

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68. So many objects,

    how to manage it?
    

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69. Long names for objects — like:
    

    Interactors::CreateUserWithTask

    Interactors::Module::CreateUserWithTask

    Interactors::Module::Module::CreateUserWithTask

    Orders::Current::Coupons::Operations::Apply
    

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70. We have to initialize
    instances every time
    

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71. Containers!
    

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72. Abstraction
    Containers
    

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73. Dry-container
    

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74. When someone tries to sell me dry-rb
    

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75. Container = Dry::Container.new
    Container.register('interactors.create_user', Interactors::CreateUser.new)
    Container['interactors.create_user']
    # => Interactors::CreateUser instance
    Container['interactors.create_user'].call(...)
    

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76. Container = Dry::Container.new
    Container.register('interactors.create_user', Interactors::CreateUser.new)
    Container['interactors.create_user']
    # => Interactors::CreateUser instance
    Container['interactors.create_user'].call(...)
    

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77. Container = Dry::Container.new
    Container.register('interactors.create_user', Interactors::CreateUser.new)
    Container['interactors.create_user']
    # => Interactors::CreateUser instance
    Container['interactors.create_user'].call(...)
    

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78. def call(params)
    result = Container['interactors.create_user'].call(params)
    if result[:successful]
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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79. Pros
    • Controlled global state (in one place)
    • Memorizing instances
    • Mocs for testing
    

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80. But we can use it
    better!
    

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81. Abstraction
    Dry-auto_inject
    

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83. Why?
    

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84. Dependency injection
    on steroids
    

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85. Import = Dry::AutoInject(Container)
    

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86. include Import[‘interactors.create_user']

    

    def call(params)
    result = create_user.call(params)
    if result[:successful]
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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87. include Import[‘interactors.create_user']

    

    def call(params)
    result = create_user.call(params)
    if result[:successful]
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    Dependency Injection ❤
    

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88. include Import[‘interactors.create_user']

    

    def call(params)
    result = create_user.call(params)
    if result[:successful]
    flash[:info] = INFO_MESSAGE
    redirect_to routes.tasks_path
    else
    self.body = …
    end
    end
    

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89. let(:action) { Create.new(create_user:
    MockObject.new) }
    it { expect(action.call(params).to eq ... }
    

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90. Abstraction
    Models
    

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91. MVC
    V and C MVC
    

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92. What can we do with it?
    

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93. No logic
    

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94. No validations
    

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95. Just save and load data
    

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96. Query objects
    

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97. Query objects
    Repositories
    

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99. Changesets

    or

    Command pattern (?)
    

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100. Drop callbacks
     

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101. Sequential logic
     

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102. Examples
     

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103. class CreateUser
     include Import['repos.user_repo']
     def call(payload)
     user_repo.create(payload.merge(created_on: Date.today
     end
     end
     CreateUser.new.call(user_data)
     

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105. Abstraction
     Applications
     

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106. Rails App #1
     Model

     Services
     

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107. Rails App #2
     Model

     Services
     Rails App #1
     Model

     Services
     

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108. Rails App #1
     Rails App #2
     Model

     Services
     

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109. Rails App #1
     Rails App #2
     Model

     Services
     Rails App #3
     Model

     Services
     

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110. Rails App #1 Rails App #3
     Rails App #2
     Model

     Services
     

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111. View Slide

112. App App App
     lib
     

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113. App App App
     lib
     Shared between apps
     

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114. View Slide

115. Actions Interactors Libs
     (public) (private)
     

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116. Apps Interactors Libs
     (public) (private)
     

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117. web

     admin #1

     admin #2 ==> business

     api logic

     mobile
     

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118. App App App
     lib
     One server instance
     

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119. App App App
     lib
     One server instance
     App App App
     lib
     App App App
     lib
     App App App
     lib
     App App App
     lib
     App App App
     lib
     App App App
     lib
     App App App
     lib
     

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120. Problems?
     

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121. Hard not to forgot

     about other apps
     

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122. Sometimes

     you have to use

     another logic
     

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124. Warning: Advanced level
     You can build projects
     without it
     

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125. Abstraction
     dry-system
     

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126. Dependency
     management system
     

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127. Auto register
     dependency to
     container
     

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132. Dependency booting
     

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133. View Slide

134. Abstraction
     Domains
     

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135. DDD
     

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137. View Slide

138. Separate domains
     for different business
     values
     

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139. Each domain
     isolated from others
     

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140. pros
     easy to create separated
     services: just replace code
     domains + containers = ❤
     

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141. cons
     hard to start
     so much files™
     

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142. View Slide

143. http is a small part

     of system
     

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144. View Slide

145. websockets
     rack
     background processing

     ETL

     …
     

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146. They all use business
     logic
     

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147. View Slide

148. System consists

     of the different events

     (Event Storming)
     

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149. View Slide

150. User created
     Post created
     User updated

     Payment added
     Order completed
     …
     

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151. Abstraction
     Event Sourcing
     

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154. View Slide

155. Events
     

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156. Event

     log
     

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157. Event

     log
     

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158. Event

     log
     

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159. View Slide

160. View Slide

161. View Slide

162. But we need to
     calculate all events
     for get current state
     

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163. CQRS

     

     (Command Query
     Responsibility
     Segregation)
     

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164. – Martin Fowler
     “You can use a different
     model to update information
     than the model you use to
     read information”
     

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165. Event log
     

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166. Event log
     SQL
     Elastic
     NoSql
     

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167. Event log
     SQL
     Elastic
     NoSql
     Current State
     

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168. Event log
     SQL
     Elastic
     NoSql
     Current State
     Current State
     

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169. Event log
     SQL
     Elastic
     NoSql
     Current State
     Current State
     Ap Ap Ap
     lib
     Ap Ap Ap
     lib
     

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170. Pros
     • Each service isolated
     • All processing is in the background
     • Easy to add instances for service
     • Can be written on any language and you
     can call it from any app
     • Persistance
     

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171. Cons
     • Not a silver bullet
     • Hard to understand the whole chain of events
     • Complicated
     • Another architecture type

     with different DB structure
     • Not popular in ruby
     

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172. How to start to use it
     

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173. View Slide

174. github.com/RailsEventStore/
     rails_event_store
     

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175. github.com/zilverline/sequent
     

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176. hanami-events
     

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177. Proof of concept
     

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178. Just pub sub
     transport layer
     with event versions
     and types
     

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179. Not only rails and hanami
     

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180. Event Sourcing
     

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181. Conclusions
     

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182. Isolate it
     

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183. Don’t use anything

     having no idea

     why do you need it
     

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184. Maintenance is
     important
     

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185. github.com/davydovanton/
     hanami-architecture
     

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186. github.com/davydovanton/
     cookie_box
     

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187. git.io/vFxl1
     

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188. -> mail@davydovanton.com
     title: RubyKaigi2k18
     

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189. github.com/davydovanton

     twitter.com/anton_davydov
     davydovanton.com
     Thank you ❤
     

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