factory

Factory

A object factory like java's spring bean factory

Features

1. Dependency Inject
2. Dynamic create object instance

Usage

Define your model

type Wheel struct {
	ID string
}

type Car struct {
	owner string

	Wheel1 *Wheel
	Wheel2 *Wheel
	Wheel3 *Wheel
	Wheel4 *Wheel
}

Register your model

factory.RegisterModel((*Wheel)(nil), "Michelin")
factory.RegisterModel((*Car)(nil), "Skoda")

Build factory

carFactory := factory.NewClassicFactory(nil)

carFactory.Define("wheel", factory.Prototype, "Michelin", factory.DefOptOfNewObjectFunc(NewWheel))

	err = carFactory.Define("mycar", factory.Prototype, "Skoda",
		factory.DefOptOfNewObjectFunc(NewCar),
		factory.DefOptOfObjectRef("Wheel1", "wheel", factory.Options{"id": "1"}),
		factory.DefOptOfObjectRef("Wheel2", "wheel", factory.Options{"id": "2"}),
		factory.DefOptOfObjectRef("Wheel3", "wheel", factory.Options{"id": "3"}),
		factory.DefOptOfObjectRef("Wheel4", "wheel", factory.Options{"id": "4"}),
	)

The func NewWheel and NewCar is your user-define new func, it should define as

func(opts Options) (v interface{}, err error)

you could get your option from Options

The car depend on wheel, so we use factory.DefOptOfObjectRef for configurate model ref, the first param is filed of Car's name, the Ref object initial order is params order, you also could use factory.DefOptOfRefOrder to define ref object initial order.

Get object

var myCar interface{}
myCar, err = carFactory.GetObject("mycar", factory.Options{"owner": "GoGap"})

if err != nil {
	fmt.Println(err)
	return
}

car := myCar.(*Car)

Example

type Hub struct {
	ID string
}

func NewHub(opts factory.Options) (hub interface{}, err error) {
	h := &Hub{}
	opts.Get("id", &h.ID)
	hub = h
	return
}

type Wheel struct {
	ID string

	Hub *Hub
}

func NewWheel(opts factory.Options) (wheel interface{}, err error) {
	w := &Wheel{}
	opts.Get("id", &w.ID)
	wheel = w
	return
}

func (p *Wheel) Run() {
	fmt.Printf("Wheel Running, ID: %s, HubID: %s\n", p.ID, p.Hub.ID)
}

type Car struct {
	owner string

	Wheel1 *Wheel
	Wheel2 *Wheel
	Wheel3 *Wheel
	Wheel4 *Wheel
}

func (p *Car) Run() {
	p.Wheel1.Run()
	p.Wheel2.Run()
	p.Wheel3.Run()
	p.Wheel4.Run()

	fmt.Printf("%s' Car Running\n", p.owner)
}

func NewCar(opts factory.Options) (car interface{}, err error) {
	c := &Car{}
	opts.Get("owner", &c.owner)
	car = c
	return
}

func init() {
	factory.RegisterModel((*Hub)(nil), "BBS")
	factory.RegisterModel((*Wheel)(nil), "Michelin")
	factory.RegisterModel((*Car)(nil), "Skoda")
}

func main() {

	var err error

	carFactory := factory.NewClassicFactory(nil)

	carFactory.Define("hub", factory.Prototype, "BBS", factory.DefOptOfNewObjectFunc(NewHub))

	carFactory.Define("wheel", factory.Prototype, "Michelin", factory.DefOptOfNewObjectFunc(NewWheel))

	err = carFactory.Define("mycar", factory.Prototype, "Skoda",
		factory.DefOptOfNewObjectFunc(NewCar),
		factory.DefOptOfObjectRef("Wheel1", "wheel", factory.Options{"id": "1"}),
		factory.DefOptOfObjectRef("Wheel2", "wheel", factory.Options{"id": "2"}),
		factory.DefOptOfObjectRef("Wheel3", "wheel", factory.Options{"id": "3"}),
		factory.DefOptOfObjectRef("Wheel4", "wheel", factory.Options{"id": "4"}),
		factory.DefOptOfObjectRef("Wheel1.Hub", "hub", factory.Options{"id": "HUB01"}),
		factory.DefOptOfObjectRef("Wheel2.Hub", "hub", factory.Options{"id": "HUB02"}),
		factory.DefOptOfObjectRef("Wheel3.Hub", "hub", factory.Options{"id": "HUB03"}),
		factory.DefOptOfObjectRef("Wheel4.Hub", "hub", factory.Options{"id": "HUB04"}),
	)

	if err != nil {
		return
	}

	var myCar interface{}
	myCar, err = carFactory.GetObject("mycar", factory.Options{"owner": "GoGap"})

	if err != nil {
		fmt.Println(err)
		return
	}

	car := myCar.(*Car)

	car.Run()
}

Output

> go run main.go
Wheel Running, ID: 1, HubID: HUB01
Wheel Running, ID: 2, HubID: HUB02
Wheel Running, ID: 3, HubID: HUB03
Wheel Running, ID: 4, HubID: HUB04
GoGap' Car Running