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What we talk about Overview What is Model What is Model How to Modeling Case Study

What we talk about Overview What is Model How to Modeling How to Modeling Case Study

What we talk about Overview What is Model How to Modeling Case Study Case Study

What is Model The Model What is Model Anyone have can sharing about it?

What is Model The Model Float 100.0 String TWD VS Money TWD $100.0

What is Model The Model Information A model is an informative representation of an object, person or system.

What is Model The Model Float 100.0 String TWD VS Money TWD $100.0 Which one can “Pay” Pay

How to Modeling Modeling Modeling How to "modeling"

Value Object Modeling Data Amount=100.0 + Data Currency=TWD Value Composite Value Money=TWD,100.0

Value Object Modeling class Money attr_reader :currency, :amount def initialize(currency, amount) @currency = currency @amount = amount end end

Entity Modeling Value ID=1 + Value Money Entity Composite Entity ID=1, Balance=Money

Entity Modeling class Wallet attr_reader :id, :balance def initialize(id, balance) @id = id @balance = balance end end

Method Modeling Entity ID=1, Balance=Money Deposit(Money) Entity ID=1, Balance=Money

Entity Modeling class Wallet attr_reader :id, :balance def initialize(id, balance) @id = id @balance = balance end end sig { params(amount: Money).returns(Money) } def deposit(amount) @balance += amount end

The Payment App Case Study The Payment App The usage of “Model” in the real-world

Analytics Case Study Customer Pay Command Transfer to Merchant System Paid Event Failed Event

Analytics Case Study Customer Pay Command Transfer to Merchant System Paid Event Failed Event Given threre have a customer “Aotoki” And I logged as “Aotoki”

Analytics Case Study Customer Pay Command Transfer to Merchant System Paid Event Failed Event When I pay for the merchant “FamilyMart”

Analytics Case Study Customer Pay Command Transfer to Merchant System Paid Event Failed Event Then I can see “Pay for FaimlyMart successful”

Analytics Case Study Customer Pay Command Transfer to Merchant System Paid Event Failed Event Then I can see “Pay for FaimlyMart failed”

Specs Case Study Feature: Scenario: Given And And When Then Payment Pay to the merchant there have a custoemr there have a merchant I logged as I pay for the merchant I can see “Aotoki” “FamilyMart” “Aotoki” “FamilyMart” “Pay for FamilyMart successful”

Specs Case Study RSpec.describe do describe subject before do end it is_expected to have_text end end , type: :request do { post payment_path, } customer = create(:customer, ) sign_in customer create(:merchant, ) { . ( ) } ‘Payment’ ‘POST /payment’ merchant_id: ‘fmart’, amount: 100 name: ‘Aotoki’, balance: 100 id: ‘fmart’ ‘Pay for FamilyMart successful’

Specs Case Study RSpec.describe do describe subject it is_expected to have_text end end , type: :request do { post payment_path, } { . ( ) } ‘Payment’ ‘POST /payment’ merchant_id: ‘fmart’, amount: 100 ‘Pay for FamilyMart successful’

Example Code Case Study def create render text: ‘Pay for FamilyMart successful’ end

Example Code Case Study class Merchant include ActiveModel::Model include ActiveModel::Attributes attribute :name, :string alias_attribute :to_s, :name end

Example Code Case Study def create render text: end merchant = Merchant.new(name: ‘FamilyMart’) “Pay for #{merchant} successful”

Example Code Case Study class Customer include ActiveModel::Model include ActiveModel::Attributes attribute :name, :string attribute :balance, :integer def withdraw(amount) raise ArgumentError, ‘insufficient balance’ if amount > self.balance self.balance -= amount end end

Example Code Case Study class Merchant include ActiveModel::Model include ActiveModel::Attributes attribute :name, :string alias_attribute :to_s, :name end attribute :balance, :integer def deposit(amount) self.balance += amount end

Example Code Case Study def create merchant = Merchant.new(name: ‘FamilyMart’) render text: “Pay for #{merchant} successful” end customer = Customer.new(name: ‘Aotoki’, balance: 100) payment_amount = params.require(:amount) customer.withdraw(payment_amount) merchant.deposit(payment_amount)

Example Code Case Study class Merchant def deposit(amount) self.balance += amount end end < ApplicationRecord

Example Code Case Study class Customer def withdraw(amount) raise ArgumentError, ‘insufficient balance’ if amount > self.balance self.balance -= amount end end < ApplicationRecord

Example Code Case Study def create payment_amount = params.require(:amount) merchant.deposit(payment_amount) render text: “Pay for #{merchant} successful” end merchant = Merchant.find_by!(id: params[:merchant_id]) current_customer.withdraw(payment_amount) ActiveRecord::Base.transaction do merchant.save! current_customer.save! end

Example Code Case Study def create merchant = Merchant.find_by!(id: params[:merchant_id]) payment_amount = params.require(:amount) current_customer.withdraw(payment_amount) merchant.deposit(payment_amount) ActiveRecord::Base.transaction do merchant.save! current_customer.save! end render text: “Pay for #{merchant} successful” end rescue ActiveRecord::RecordInvalid render text: “Pay for #{merchant} failed”

Example Code Case Study class Money include ActiveModel::Model include ActiveModel::Attributes attribute :value, :integer def +(other) Money.new(value: self.value + other.value) end def -(other) raise ArgumentError, ‘Money cannot be negative’ if other.value > self.value Money.new(value: self.value - other.value) end end

Example Code Case Study class Merchant < ApplicationRecord def deposit(amount) self.balance += amount end end composed_of :balance, class_name: ‘Money’, mapping: %[balance value]

Example Code Case Study class Customer < ApplicationRecord def withdraw(amount) self.balance -= amount end end composed_of :balance, class_name: ‘Money’, mapping: %[balance value]

Example Code Case Study def create merchant = Merchant.find_by(id: params[:merchant_id]) current_customer.withdraw(payment_amount) merchant.deposit(payment_amount) ActiveRecord::Base.transaction do merchant.save! current_customer.save! end render text: “Pay for #{merchant} successful” rescue ActiveRecord::RecordInvalid render text: “Pay for #{merchant} failed” end payment_amount = Money.new(value: params.require(:amount))

Example Code Case Study def create merchant = Merchant.new(name: ‘FamilyMart’) ActiveRecord::Base.transaction do merchant.save! current_customer.save! end render text: “Pay for #{merchant} successful” rescue ActiveRecord::RecordInvalid render text: “Pay for #{merchant} failed” end context = BuyingContext.new input = PaymentInput.new(params) context.pay(to: merchant, from: current_customer, amount: input.amount)

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