Experiences decoupling Ulabox.com codebase in order to ease the transition between a traditional CRUD model to a DDD model

1. Decoupling Ulabox.com
monolith
From CRUD to DDD

2. Aleix Vergés
Backend developer
Scrum Master
@avergess
aleix.verges@ulabox.com

3. 1. What’s Ulabox?

8. 2. Decoupling. Why?

9. /**
* @param Cart $cart
* @return Order $order
*/
public function createOrder(Cart $cart)
{
// Year 2011
$order = $this->moveCartToOrder($cart);
$this->sendConfirmationEmail($order);
$this->reindexSolr($order);
$this->sendToWarehouse($order);
// Year 2012
$this->sendToFinantialErp($order);
$this->sendDonationEmail($order);
// Year 2014
$this->sendToDeliveryRoutingSoftware($order);
// Year 2015
$this->sendToJustInTimeSuppliers($order);
// Year 2016
$this->sendToWarehouseSpoke($order); // WTF!
$this->sendToShipLoadSoftware($order); // WTF!!!!
}
Decoupling Ulabox.com monolith. From CRUD to DDD
Our problem

10. WTF!

11. Past
● CRUD doesn’t make sense anymore
● It had sense at the beginning
● Product, Logistic, Delivery, Cart, Customers, ...
● It’s not sustainable.
Decoupling Ulabox.com monolith. From CRUD to DDD

12. Our solution
/**
* @param Cart $cart
*/
public function createOrder(Cart $cart)
{
$createOrder = new CreateOrderCommand(Cart $cart);
$this->commandBus->dispatch($createOrder)
}
Event bus
CreateOrder command
OrderWasCreated event
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Decoupling Ulabox.com monolith. From CRUD to DDD

13. 3. The tools

14. ● Domain
● Aggregate / Aggregate Root
● Repository
● Domain Events
● Service
● Command Bus
● Event Bus
* Domain Drive Design: https://en.wikipedia.org/wiki/Domain-driven_design
Decoupling Ulabox.com monolith. From CRUD to DDD

15. 4. A responsability question

16. Refactoring and manage technical debt is
not a choice, but a responsability
Decoupling Ulabox.com monolith. From CRUD to DDD

17. 5. Controllers

18. REFUND!

19. 5.1. OrderController
5. Controllers

20. class OrderController extends BaseController
{
public function refundAction(Request $request, $id)
{
$em = $this->container->get('doctrine.orm.entity_manager');
$orderPayment = $em->getRepository('UlaboxCoreBundle:OrderPayment')->find($id);
$amount = $request->request->get('refund');
$data = $this->container->get('sermepa')->processRefund($orderPayment, $amount);
$orderRefund = new OrderPayment();
$orderRefund->setAmount($amount);
...
$em->persist($orderRefund);
$em->flush();
return $this->redirectToRoute('order_show', ['id' => $orderPayment->getOrder()->getId()]);
}
public function someOtherAction(Request $request, $id)
...
}

21. Decoupling Ulabox.com monolith. From CRUD to DDD
Problems
● Hidden dependencies
● Inheritance.
● Biz logic in the controller.
● Non aggregate root.
● Difficult to test.

22. * Dependency Injection: https://es.wikipedia.org/wiki/Inyecci%C3%B3n_de_dependencias
Decoupling Ulabox.com monolith. From CRUD to DDD
Solutions
● Dependency Injection
● Break inheritance from base controller.
● Application services.
● Testing

23. 5.2. Controller as a service
5. Controllers

24. # services.yml
imports:
- { resource: controllers.yml }
# controllers.yml
ulabox_ulaoffice.controllers.order:
class: UlaboxUlaofficeBundleControllerOrderController
arguments:
- '@refund'
- '@router'
...

25. 5. Controllers
5.3. Dependency Injection

26. /**
* @Route("/orders", service="ulabox_ulaoffice.controllers.order")
*/
class OrderController
{
/**
* @param Refund $refund
* @param RouterInterface $router
*/
public function __construct(Refund $refund, RouterInterface $router, ……..)
{
$this->refund = $refund;
$this->router = $router;
...
}
}

27. 5. Controllers
5.4. Delegate logic to services

28. /**
* @Route("/orders", service="ulabox_ulaoffice.controllers.order")
*/
class OrderController
{
public function refundAction(Request $request, $id)
{
$amount = $request->request->get('refund');
$method = $request->request->get('method');
$orderId = $request->request->get('order_id');
try {
$this->refund->execute($orderId, $id, (float)$amount, $method);
$this->session->getFlashBag()->add('success', 'Refund has been processed correctly');
} catch (Exception $e) {
$this->session->getFlashBag()->add('danger', $e->getMessage());
}
return new RedirectResponse($this->router->generate('order_show', ['id' => $orderId]));
}
}

29. 5. Controllers
5.5. Unit test

30. class OrderControllerTest extends PHPUnit_Framework_TestCase
{
public function setUp()
{
$this->refund = $this->prophesize(Refund::class);
$this->router = $this->prophesize(RouterInterface::class);
$this->orderController = new OrderController(
$this->refund->reveal(),
$this->router->reveal()
);
}
...
}

31. class OrderControllerTest extends PHPUnit_Framework_TestCase
{
...
public function testShouldDelegateOrderRefund()
{
$orderPaymentId = 34575;
$amount = 10.95;
$orderId = 12345;
$orderRoute = 'some/route';
$request = $this->mockRequest($orderId, $orderPaymentId, $amount, $orderRoute);
$this->refund
->execute($orderId, $orderPaymentId, $amount, PaymentPlatform::REDSYS)
->shouldBeCalled();
$this->router->generate('order_show', ['id' => $orderId])->willReturn($orderRoute);
$actual = $this->orderController->refundAction($request->reveal(), $orderPaymentId);
$this->assertEquals(new RedirectResponse($orderRoute), $actual);
}
}

32. 6. Symfony Forms

33. RESCHEDULE

34. 6. Symfony Forms
6.1. Anemic Model

35. class OrderController extends BaseController
{
public function rescheduleAction(Request $request, $id)
{
$order = $this->container->get('order')->reposition($id);
$form = $this->createForm(new OrderType(), $order);
$form->handleRequest($request);
if ($form->isValid()) {
$em = $this->getDoctrine()->getManager();
$em->persist($order);
$em->flush();
$request->getSession()->getFlashBag()->add('success', 'Your changes were saved!');
return $this->redirect($this->generateUrl('reschedule_success'));
}
return ['entity' => $entity, 'form' => $form->createView()];
}
}

36. Decoupling Ulabox.com monolith. From CRUD to DDD
Problems
● Coupling between entities and Symfony Forms.
● Anemic Model.
● Intention?

37. Decoupling Ulabox.com monolith. From CRUD to DDD
Solutions
● Use of DTO/Command
● Reflect the Intention!
● Rich Domain.
● Testing.

38. 6. Symfony Forms
6.2. Command !== CLI Command

39. class Reschedule
{
public $orderId;
public $addressId;
public $slotVars;
public $comments;
public function __construct($orderId, $addressId, $slotVars, $comments)
{
$this->orderId = $orderId;
$this->addressId = $addressId;
$this->slotVars = $slotVars;
$this->comments = $comments;
}
}

40. 6. Symfony Forms
6.3. Building the Form

41. class OrderController extends BaseController
{
public function rescheduleDisplayingAction(Request $request, $id)
{
$order = $this->orderRepository->get($id);
$address = $order->deliveryAddress()->asAddress();
$rescheduleOrder = Reschedule::fromPayload([
'order_id' => $order->getId(),
'address_id' => $address->getId(),
'slot_vars' => $order->deliverySlotVars(),
'comments' => $order->deliveryComments(),
]);
$rescheduleForm = $this->formFactory->create(OrderRescheduleType::class, $rescheduleOrder);
return ['order' => $order, 'form' => $rescheduleForm->createView()];
}
}

42. 6. Symfony Forms
6.4. Submitting the Form

43. class OrderController extends BaseController
{
public function rescheduleUpdateAction(Request $request, $id)
{
$requestData = $request->get('order_reschedule');
$rescheduleOrder = Reschedule::fromPayload([
'order_id' => $id,
'address_id' => $requestData['addressId'],
'slot_vars' => $requestData['slotVars'],
'comments' => $requestData['comments'],
]);
$rescheduleForm = $this->formFactory->create(OrderRescheduleType::class, $rescheduleOrder);
if ($rescheduleForm->isValid()) {
$this->commandBus->dispatch($rescheduleOrder);
}
return new RedirectResponse($this->router->generate($this->entity Properties['route']));
}
}

44. 6. Symfony Forms
6.5. Unit test

45. class OrderControllerTest extends PHPUnit_Framework_TestCase
{
public function testShouldDelegateOrderRescheduleToCommandBus()
{
$orderId = 12345;
$addressId = 6789;
$slotVars = '2016-03-25|523|2|15';
$comments = 'some comments';
$expectedRoute = 'http://some.return.url';
$request = $this->mockRequest($orderId, $addressId, $slotVars, $comments);
$form = $this->mockForm();
$form->isValid()->willReturn(true);
$this->router->generate('order')->willReturn($expectedRoute);
$this->commandBus->dispatch(Argument::type(Reschedule::class))->shouldBeCalled();
$actual = $this->orderController->rescheduleUpdateAction($request->reveal(), $orderId);
$this->assertEquals(new RedirectResponse($expectedRoute), $actual);
}
}

46. 7. From CRUD to DDD

47. 7. From CRUD to DDD
7.1. Summing...

48. class OrderController extends BaseController
{
public function rescheduleUpdateAction(Request $request, $id)
{
$requestData = $request->get('order_reschedule');
$rescheduleOrder = Reschedule::fromPayload([
'order_id' => $id,
'address_id' => $requestData['addressId'],
'slot_vars' => $requestData['slotVars'],
'comments' => $requestData['comments'],
]);
$rescheduleForm = $this->formFactory->create(OrderRescheduleType::class, $rescheduleOrder);
if ($rescheduleForm>isValid()) {
$this->commandBus->dispatch($rescheduleOrder);
}
return new RedirectResponse($this->router->generate($this->entity Properties['route']));
}
}

49. 7. From CRUD to DDD
7.2. Handling

50. class RescheduleHandler extends CommandHandler
{
public function __construct( ... ) { ... }
public function handleReschedule(Reschedule $rescheduleOrder)
{
$timeLineSlot = $this->slotManager->createTimelineSlotFromVars($rescheduleOrder->slotVars);
$order = $this->orderRepository->get($rescheduleOrder->aggregateId);
$delivery = $order->getOrderDelivery();
$delivery->setSlot($timeLineSlot->getSlot());
$delivery->setLoadTime($timeLineSlot->getLoadTime());
$delivery->setShift($timeLineSlot->getShift()->getShift());
...
$order->rescheduleDelivery($delivery);
$this->orderRepository->save($order);
$this->eventBus->publish($order->getUncommittedEvents());
}
}

51. Decoupling Ulabox.com monolith. From CRUD to DDD
Problems
● Biz logic out of domain.
● Aggregate access.
● Aggregate Root?
● Unprotected Domain.

52. Decoupling Ulabox.com monolith. From CRUD to DDD
Solutions
● Aggregate Root. Order or Delivery?
● Unique acces point to the domain.
● Clear intention!!
● Testing.

53. 7. From CRUD to DDD
7.3. Order or Delivery?

55. 7. From CRUD to DDD
7.4. Aggregate access point

56. class RescheduleHandler extends CommandHandler
{
public function __construct( ... ) { ... }
public function handleReschedule(Reschedule $rescheduleDelivery)
{
$timeLineSlot = $this->slotManager->createTimelineSlotFromVars($rescheduleDelivery->slotVars);
$delivery = $this->deliveryRepository->get($rescheduleDelivery->deliveryId);
$delivery->reschedule($timeLineSlot);
$this->deliveryRepository->save($delivery);
$this->eventBus->publish($delivery->getUncommittedEvents());
}
}

57. 7. From CRUD to DDD
7.5. Business logic

58. class Delivery implements AggregateRoot
{
public function reschedule(TimelineSlot $timelineSlot)
{
$this->setDate($timelineSlot->getDate());
$this->setLoadTime($timelineSlot->getLoadTime());
$this->setSlot($timelineSlot->getSlot());
$this->setShift($timelineSlot->getShift());
$this->setLoad($timelineSlot->getLoad());
$this->setPreparation($timelineSlot->getPreparationDate());
$this->apply(
new DeliveryWasRescheduled(
$this->getAggregateRootId(),
$this->getProgrammedDate(),
$this->getTimeStart(),
$this->getTimeEnd(),
$this->getLoad()->spokeId()
)
);
}
}

59. 7. From CRUD to DDD
7.6. Unit test

60. class RescheduleHandlerTest extends PHPUnit_Framework_TestCase
{
public function testShouldRescheduleDelivery()
{
$deliveryId = 12345;
$slotVars = '2016-03-25|523|2|15';
$timeLineSlot = TimelineSlotStub::random();
$delivery = $this->prophesize(Delivery::class);
$this->deliveryRepository->get($deliveryId)->willReturn($delivery);
$this->slotManager->createTimelineSlotFromVars($slotVars)->willReturn($timeLineSlot);
$delivery->reschedule($timeLineSlot)->shouldBeCalled();
$this->deliveryRepository->save($delivery)->shouldBeCalled();
$this->eventBus->publish($this->expectedEvents())->shouldBeCalled();
$this->rescheduleOrderHandler->handleReschedule(new Reschedule($deliveryId, $slotVars));
}
}

61. class DeliveryTest extends PHPUnit_Framework_TestCase
{
public function testShouldRescheduleDelivery()
{
$delivery = OrderDeliveryStub::random();
$timeLineSlot = TimelineSlotStub::random();
$delivery->reschedule($timeLineSlot);
static::assertEquals($timeLineSlot->getDate(), $delivery->getProgrammedDate());
static::assertEquals($timeLineSlot->getLoadTime(), $delivery->getLoadTime());
static::assertEquals($timeLineSlot->getSlot(), $delivery->getSlot());
static::assertEquals($timeLineSlot->getShift(), $delivery->getShift());
static::assertEquals($timeLineSlot->getPreparationDate(), $delivery->getPreparation());
$messageIterator = $delivery->getUncommittedEvents()->getIterator();
$this->assertInstanceOf(
DeliveryWasRescheduled::class, $messageIterator->current()->getPayload()
);
}
}

62. 7. From CRUD to DDD
7.7. Domain event

63. DeliveryWasRescheduled
Delivery Order
Load
Slot
TimeStart
Date
OrderLine
Product
Tax
Deliveries Orders

64. 8. Aggregates and Repositories

65. CREDIT CARDS

66. 8. Aggregates and Repositories
8.1. Entity / Repository

67. class CustomerCreditcardModel
{
public function add($number, $type, $token = null, $expiryDate = null)
{
$customer = $this->tokenStorage->getToken()->getUser();
$creditCard = new CustomerCreditcard();
$creditCard->setNumber($number);
$creditCard->setCustomer($customer);
$creditCard->setType($type);
$creditCard->setToken($token);
$creditCard->setExpiryDate($expiryDate);
$this->creditCardRepository->add($creditCard);
return $creditCard;
}
}

68. Decoupling Ulabox.com monolith. From CRUD to DDD
Problems
● Aggregate?
● CreditCardRepository???
● Unprotected Domain.

69. Decoupling Ulabox.com monolith. From CRUD to DDD
Solutions
● Which is the Aggregate?
● What’s the Intention?
● Testing

70. Customer
CreditCard
class Customer implements AggregateRoot
{
public function addCreditCard($number, $type, $token = '', $expiryDate = '')
{
$creditCard = CustomerCreditcard::create($number, $type, $token, $expiryDate);
$this->creditCards->add($creditCard);
$this->apply(new CreditCardWasRegistered($this->getAggregateRootId(), $number));
}
}
Decoupling Ulabox.com monolith. From CRUD to DDD

71. 8. Aggregates and Repositories
8.2. RegisterCreditCard

72. class RegisterCreditCard
{
public $customerId;
public $cardNumber;
public $type;
public $token;
public $expiry;
public function __construct($customerId, $cardNumber, $type, $token, $expiry)
{
$this->customerId = $customerId;
$this->cardNumber = $cardNumber;
$this->type = $type;
$this->token = $token;
$this->expiry = $expiry;
}
}

73. 8. Aggregates and Repositories
8.3. RegisterCreditCardHandler

74. class RegisterCreditCardHandler extends CommandHandler
{
private $customerRepository;
private $eventBus;
public function __construct( ... ) { ... }
public function handleRegisterCreditCard(RegisterCreditCard $registerCreditCard)
{
$customer = $this->customerRepository->get($registerCreditCard->customerId())
$customer->addCreditCard(
$registerCreditCard->cardNumber(),
$registerCreditCard->type(),
$registerCreditCard->token(),
$registerCreditCard->expiry()
);
$this->customerRepository->save($customer);
$this->eventBus->publish($customer->getUncommittedEvents());
}
}

75. 8. Aggregates and Repositories
8.4. Business rules

76. class Customer implements AggregateRoot
{
public function addCreditCard($number, $type, $token, $expiryDate)
{
if ($this->creditCardExists($number, $type)) {
$this->renewCreditCard($number, $type, $token, $expiryDate);
return;
}
$creditCard = CustomerCreditcard::create($number, $type, $token, $expiryDate);
$this->creditCards->add($creditCard);
$this->apply(new CreditCardWasRegistered($this->getAggregateRootId(), $number));
}
private function renewCreditCard($number, $type, $token, $expiryDate)
{
...
}
}

77. 9. Learned lessons

78. This is not a Big-Bang
Decoupling Ulabox.com monolith. From CRUD to DDD

79. Aggregate Election
Decoupling Ulabox.com monolith. From CRUD to DDD

80. Communication
Decoupling Ulabox.com monolith. From CRUD to DDD

81. Team
Decoupling Ulabox.com monolith. From CRUD to DDD

82. ¡¡¡Be a Professional!!!
Decoupling Ulabox.com monolith. From CRUD to DDD

83. @avergess
aleix.verges@ulabox.com
www.linkedin.com/in/avergess
Thank’s
Questions?