Template Method Pattern

Template Method Pattern

※ 情境 : 當多個類的演算法除了一些細微不同之外，其他幾乎完全一樣時，可以使用樣板方法模式。但其後果就是，只要演算法發生變化，你就可能需要修改所有的類。

Interface

type SpendMoney interface {
	goToStore()
	buySomething()
	pay()
	goHome()
}

Template

type Shopping struct {
}

func (s *Shopping) goToStore() {
}

func (s *Shopping) buySomething() {
}

func (s *Shopping) pay() {
	fmt.Println("Pay money.")
}

func (s *Shopping) goHome() {
	fmt.Println("Go home.")
}

func GoShopping(shop SpendMoney) {
	shop.goToStore()
	shop.buySomething()
	shop.pay()
	shop.goHome()
}

type Shoes struct {
	Shopping
}

func (s *Shoes) goToStore() {
	fmt.Println("Go to Nike.")
}

func (s *Shoes) buySomething() {
	fmt.Println("Buy the slippers.")
}

type Handbag struct {
	Shopping
}

func (h *Handbag) goToStore() {
	fmt.Println("Go to the department store.")
}

func (h *Handbag) buySomething() {
	fmt.Println("Buy the GUCCI.")
}

Test

package test

import (
	"DesignPatterns/TemplateMethodPattern"
	"testing"
)

func TestTemplateMethodPattern(t *testing.T) {
	shoes := &TemplateMethodPattern.Shoes{}
	TemplateMethodPattern.GoShopping(shoes)

	handbag := &TemplateMethodPattern.Handbag{}
	TemplateMethodPattern.GoShopping(handbag)
}