Abstract Factory Pattern

Abstract Factory Pattern

※ 情境 : 如果程式碼需要與多個不同系列的相關產品互動， 但是由於無法提前獲取相關資訊， 或者出於對未來擴展性的考慮， 你不希望程式碼基於產品的具體類進行建構， 在這種情況下， 你可以使用抽象工廠。

Interface

type Shirts interface {
	HasSleeves()
	SuitableFor()
}

type Pants interface {
	FullLength()
	SuitableFor()
}

type ClothesFactory interface {
	MakeShirts() Shirts
	MakePants() Pants
}

Office Clothes

type WorkShirts struct{}

func (w WorkShirts) HasSleeves() {
	fmt.Println("Yes!! long sleeves.")
}

func (w WorkShirts) SuitableFor() {
	fmt.Println("Office wear.")
}

type WorkPants struct{}

func (w WorkPants) FullLength() {
	fmt.Println("Pants of 100 cm.")
}

func (w WorkPants) SuitableFor() {
	fmt.Println("Office wear.")
}

Home Clothes

type VacationShirts struct{}

func (v VacationShirts) HasSleeves() {
	fmt.Println("No!! no sleeves.")
}

func (v VacationShirts) SuitableFor() {
	fmt.Println("Home wear.")
}

type VacationPants struct{}

func (v VacationPants) FullLength() {
	fmt.Println("Pants of 50 cm.")
}

func (v VacationPants) SuitableFor() {
	fmt.Println("Home wear.")
}

Office Factory

type OfficeFactory struct{}

func (o *OfficeFactory) MakeShirts() Shirts {
	return WorkShirts{}
}

func (o *OfficeFactory) MakePants() Pants {
	return WorkPants{}
}

Home Factory

type HomeFactory struct{}

func (h *HomeFactory) MakeShirts() Shirts {
	return VacationShirts{}
}

func (h *HomeFactory) MakePants() Pants {
	return VacationPants{}
}

Test

package test

import (
	"DesignPatterns/AbstractFactoryPattern"
	"testing"
)

func TestAbstractFactoryPattern(t *testing.T) {
	var factory AbstractFactoryPattern.ClothesFactory

	clothesStyle := buyClothes()
	switch clothesStyle {
	case "Office":
		factory = &AbstractFactoryPattern.OfficeFactory{}
	case "Home":
		factory = &AbstractFactoryPattern.HomeFactory{}
	default:
		panic("Undefined clothes style")
	}

	shirts := factory.MakeShirts()
	shirts.HasSleeves()
	shirts.SuitableFor()

	pants := factory.MakePants()
	pants.FullLength()
	pants.SuitableFor()
}

func buyClothes() string {
	return "Home"
}