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蒼時弦也看網站開發框架隠藏的細節從Domain-Driven Design

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CONSULTANT × SPEAKER 蒼時弦也 YouTube Coding Live Blog https://blog.aotoki.me Discord Discuss about Ruby Introduce About Me

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What we talk about Overview The Layers The case study Why Domain-Driven Design Why Domain-Driven Design

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What we talk about Overview The Layers The Layers The case study Why Domain-Driven Design

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What we talk about Overview The Layers The case study The case study Why Domain-Driven Design

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Opportunity Why Domain-Driven Design The Opportunity When I try to improve the code base

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Framework and Design Why Domain-Driven Design Design Architecture Framework

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Escape Why Domain-Driven Design Framework Ruby / PHP Framework Node.js / Golang Replace

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Modeling Why Domain-Driven Design The Modeling From data to information

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Modeling Why Domain-Driven Design Data State Action Modeling Change Object

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Layered Architecture The Layers Layered Architecture Define the role of your "Class"

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Presentation Layer The Layers Presentation Layer Transform between "data" and "object"

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Presentation Layer The Layers Object @product.name Data

Product

Render Output (View) Rails View

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Presentation Layer The Layers Object @product.name Data {"name": "Product"} Serialize Output (View) Rails View

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Presentation Layer The Layers Data {"name":"Product"} Object params[:name] Deserialize Input (Param) Rails Controller

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Application Layer The Layers Application Layer Define the flow of "action"

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Application Layer The Layers Input User Flow Order.create! Payment.create! OrderMailer.confirmation

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Application Layer The Layers Input User Flow Order.create! Payment.create! OrderMailer.confirmation Exception PaymentGatewayUnavailable Raise

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Application Layer The Layers Input User Flow Order.create! Payment.create! OrderMailer.confirmation Input User Flow Order.find_or_create_by! Payment.create! OrderMailer.confirmation Idempotent

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Domain Layer The Layers Domain Layer The "logic" related business

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Domain Layer The Layers Period begin=2022-09-01, end=2022-10-31 Call in? 2022-09-30 Return true Value Object

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Domain Layer The Layers Data State Action Modeling Change Entity

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Domain Layer The Layers ShippingService#create_ticket!(order) if response.success? True order.shipping_id = response.id False raise ShippingProviderUnavailable Service Object

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Infrastructure Layer The Layers Infrastructure Layer The way to interact with "data"

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Infrastructure Layer The Layers PostgresOrderRepository implement IOrderRepository Write Read Orders Table Repository

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Infrastructure Layer The Layers ShopifyOrderRepository implement IOrderRepository Call Shopify Order API Write Read Orders Table Repository

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Testing The Layers Add Tests The reasonable way to test

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Testing The Layers shipped.json.jbuilder ShippingController Order OrderRepository UserRepository Shipping ShippingRepository TicketRepository DHL::Client E2E Testing

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Testing The Layers shipped.json.jbuilder ShippingController Order OrderRepository UserRepository Shipping ShippingRepository TicketRepository DHL::Client E2E Testing

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Testing The Layers shipped.json.jbuilder ShippingController Order OrderRepository UserRepository Shipping ShippingRepository TicketRepository DHL::Client Unit Test

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Testing The Layers shipped.json.jbuilder ShippingController Order OrderRepository UserRepository Shipping ShippingRepository TicketRepository DHL::Client Unit Test

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Testing The Layers shipped.json.jbuilder ShippingController Order OrderRepository UserRepository Shipping ShippingRepository TicketRepository DHL::Client Workable Feature

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Input Object Case Study Input Object How to "validate" the inputs

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Input Object Case Study Input Profile @user.assign_attributes(params) @user.valid! @user.save!

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Input Object Case Study Input Register @user = User.new(params) @user.valid! @user.save!

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Input Object Case Study Input Register @form.valid! @user = User.new(@form.attributes) @user.save!

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Input Object Case Study # Ruby on Rails validates :email, :password, presence: true validates :email, format: /\A[^@\s]+@[^@\s]+\z/ class RegisterForm include ActiveModel::API include ActiveModel::Validation attribute :email, :string attribute :password, :string end

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Input Object Case Study // NestJS class RegisterDto { email: string; password: string; } @IsEmail() @IsNotEmpty() @Post() @UsePipes(new ValidationPipe({ transform: true })) async create(@Body() registerDto: RegisterDto) { this.registrationService.create(registerDto); }

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Input Object Case Study // NestJS @UsePipes(new ValidationPipe({ transform: true })) class RegisterDto { @IsEmail() email: string; @IsNotEmpty() password: string; } @Post() async create(@Body() registerDto: RegisterDto) { this.registrationService.create(registerDto); }

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Input Object Case Study Input Steps Parse Request Validate DTO Dispatch Controller

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Input Object Case Study // Pseudo Code function dispatch(request: HttpRequest) { controller, action = this.router.lookup(request.path) input = meta.inputs[action].build(request.params) controller[action].call(input) } meta = Reflect.getMeta(controller) validator = meta.validator[action] if (validator) { validator.validate(input) }

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Error Handling Case Study Error Handling Where to fix the error?

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Error Handling Case Study Input Order.create! Payment.create! OrderMailer.confirmation Exception PaymentGatewayUnavailable Raise

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Error Handling Case Study # Ruby on Rails rescue PaymentGateWayUnavailable render :new class OrderController < ApplicationController def create @order = Order.create!(params) @payment = Payment.create!(order: @order) OrderMailer.confirmation(@order) end end

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Error Handling Case Study # Ruby on Rails rescue_from ActiveRecord::ActiveRecordError, with: :record_error rescue_from PaymentService::PaymentError, with: :payment_error class OrderController < ApplicationController def create @order = Order.create!(params) @payment = Payment.create!(order: @order) OrderMailer.confirmation(@order) end end

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Error Handling Case Study # Ruby on Rails @form = CreaetOrderForm.new(params) def payment_error(exc) @form.errors.add(:base, exc.message) render :new end class OrderController < ApplicationController rescue_from ActiveRecord::ActiveRecordError, with: :record_error rescue_from PaymentService::PaymentError, with: :payment_error def create # ... end end

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Error Handling Case Study # Ruby on Rails module WithPaymentFlow # ... included do rescue_from PaymentService::PaymentError, with: :payment_flow_error end def payment_flow_error(exc) @form.errors.add(:base, exc.message) end end # response_with(@form)

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Error Handling Case Study ActiveSupport::Rescuable ActionController ActionMailer ActionCable ActiveJob

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Side Effect Case Study Side Effect Who changes my data?

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Side Effect Case Study # Ruby on Rails class ShippingService # ... def refresh_shipping_state!(order, ticket) end end order.update( shipping_state: ticket.shipping_state, # ... )

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Side Effect Case Study # Ruby on Rails class Merchant::ShippingController < ApplicationController # ... def update ticket = ShippingTicket.from_order!(@order) shipping_service.refresh_shipping_state!(@order, ticket) # ... @order.save! end end tracking_service.attach_event!(@order) #=> TrackingUnavailableError

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Side Effect Case Study # Ruby on Rails class ShippingService # ... end def refresh_shipping_state(order, ticket) order.assign_attributes( shipping_state: ticket.shipping_state, # ... ) end

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Side Effect Case Study # Ruby on Rails class Merchant::ShippingController < ApplicationController # ... def update # User Flow ticket = ShippingTicket.from_order!(@order) shipping_service.refresh_shipping_state(@order, ticket) tracking_service.attach_event!(@order) # Commit @order.save! end end # Input # ...

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Side Effect Case Study # Ruby on Rails class Merchant::ShippingController < ApplicationController # ... def update # Input # ... # Commit @order.save! end end # User Flow ticket = ShippingTicket.from_order!(@order) shipping_service.refresh_shipping_state(@order, ticket) tracking_service.attach_event!(@order)

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Side Effect Case Study # Ruby on Rails class Merchant::ShippingController < ApplicationController # ... def update # Input # ... # User Flow ticket = ShippingTicket.from_order!(@order) shipping_service.refresh_shipping_state(@order, ticket) tracking_service.attach_event!(@order) end end # Commit @order.save!

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Value Object Case Study Value Object Manage logic in the "Domain Model"

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Value Object Case Study # Ruby on Rails class Wallets::DepositController < ApplicationController def create # ... @wallet.save! end end @wallet.deposit(@form[‘amount’], @form[‘currency’])

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Value Object Case Study # Ruby on Rails class Wallet < ApplicationRecord # ... def deposit(amount, currency) self.balance += amount end end raise CurrencyMismatch unless self.currency == currency

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Value Object Case Study # Ruby on Rails class Wallet < ApplicationRecord # ... def deposit(amount) end end sig {params(amount: Money).returns(Money)} self.balance += amount

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Value Object Case Study # Ruby on Rails class Money # ... end def +(other) raise ArgumentError, ‘...’ unless other.currency == currency Money.new(amount + other.amount, currency) end raise ArgumentError, ‘...’ unless other.is_a?(Money)

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Value Object Case Study # Ruby on Rails class Wallet < ApplicationRecord # ... sig {params(amount: Money).returns(Money)} def deposit(amount) end end composed_of :balance, class_name: ‘Money’, mapping: [%i[balance amount], %i[currency currency]] self.balance += amount

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Value Object Case Study # Ruby on Rails class Wallets::DepositController < ApplicationController def create # ... @wallet.save! end end @wallet.deposit(@form.amount)

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Value Object Case Study # Ruby on Rails class Wallets::DepositController < ApplicationController def create # ... @wallet.save! end end @wallet.balance += @form.amount

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