Function nextID

11_app_dev/chaincode_example03.go:366–375

(ctx contractapi.TransactionContextInterface, counterKey string)

}

func nextID(ctx contractapi.TransactionContextInterface, counterKey string) (int, error) {
	id, err := currentID(ctx, counterKey)
	if err != nil {
		return 0, err
	}
	if err := ctx.GetStub().PutState(counterKey, []byte(strconv.Itoa(id+1))); err != nil {
		return 0, fmt.Errorf("failed to update counter %s: %w", counterKey, err)
	}
	return id, nil
}

func currentID(ctx contractapi.TransactionContextInterface, counterKey string) (int, error) {
	data, err := ctx.GetStub().GetState(counterKey)