}
type bookManagment Managment
var BookM = &bookManagment{DB: db.DB}
func NewBookWithID(id string) (book Book, err error) {
if i, err := strconv.ParseUint(id, 10, 64); err == nil {
book = Book{}
book.ID = uint(i)
}
return
}
// define states
var BookStateMachine = transition.New(&Book{})
func initBookState() {
BookStateMachine.Initial("Preparing")
BookStateMachine.State("Available")
BookStateMachine.State("Salling")
BookStateMachine.Event("Roll").To("Available").From("Preparing")
BookStateMachine.Event("Discount").To("Salling").From("Available")
}
// methods for bookManagment
func (b *bookManagment) Create(book *Book) bool {
b.DB.Create(book)
return b.DB.NewRecord(book)
}
transition.Transition
}
func (order Order) Amount() (amount float32) {
for _, orderItem := range order.OrderItems {
amount += orderItem.Amount()
}
return
}
func (item OrderItem) Amount() float32 {
return item.Price * float32(item.Quantity) * float32(100-item.DiscountRate) / 100
}
var (
OrderState = transition.New(&Order{})
ItemState = transition.New(&OrderItem{})
)
func init() {
// Define Order's States
OrderState.Initial("draft")
OrderState.State("checkout")
OrderState.State("cancelled").Enter(func(value interface{}, tx *gorm.DB) error {
// release stock, change items's state
return nil
})
OrderState.State("paid").Enter(func(value interface{}, tx *gorm.DB) error {
// freeze stock, change items's state
return nil
})
package models
import (
"github.com/jinzhu/gorm"
"github.com/qor/qor/transition"
)
type Order struct {
gorm.Model
Description string
transition.Transition
}
var OrderStateMachine = transition.New(&Order{})
func init() {
OrderStateMachine.Initial("pending")
}