Implementing DDD in your Symfony project

This presentation shows a simple approach of a DDD implementation in a Symfony project.
Was exposed in deSymfonyDay 2014 (Barcelona)

Transcript

1. Sergio Moya @soyelsergillo
   * $* *!# %
   !%
   $* **
   
   

   View Slide

2. $ *$# %& $ *
   Backend Engineer at Social Point
   !
   DDD Fan
   !
   Hip Hop Culture lover
   !
   Badaloní (from Badalona)
   $# *!
   (
   ((($# *$
   

   View Slide

3. (%(($
   An example of a Business requested feature
   based on a TRUE STORY
   Project file distribution
   The Domain Model
   Use of Domain Events
   Adapter for our component
   !
   Integrating in our Symfony Project
   

   View Slide

4. 
   
   
   
   
   %)%
   &"&% &$
   &
   )!#%
   &
   %)%
   * &##
   
   
   

   View Slide

5. &"&% &$
   &
   &

   %)%
   
   A sphere of knowledge,
   influence, or activity. The
   subject area to which the
   user applies a program is
   the domain of the
   software.
   A description of a
   boundary (typically a
   subsystem, or the work of
   a particular team) within
   which a particular model
   is defined and applicable.
   A language structured
   around the domain model
   and used by all team
   members within a
   bounded context to
   connect all the activities
   of the team with the
   software.
   %$$
   

   View Slide

6. KNOW YOUR
   UBIQUITOUS LANGUAGE
   

   View Slide

7. The Lead of the Backend engineers team has decided to split the team into smaller
   two-member teams.
   !
   Each team will develop a different component.
   !
   Our team will develop the Payment Component
   

   View Slide

8. View Slide

9. %#"&#%$
   THERE IS NO BASKET OR CART
   !
   ONE PRODUCT, ONE ORDER
   !
   A PRODUCT WILL HAVE CONDITIONS TO BE PURCHASED
   !
   THE SYSTEM SHOULD TRACK THE ORDERS
   

   View Slide

10. &$% #
    ##
    
    !# &%
    *
    

    View Slide

11. View Slide

12. #%%&
    

    View Slide

13. #%%%$
    

    View Slide

14. %%%* ##
    /**!
    * CustomerOrder!
    *!
    * @ORM\Table()!
    * @ORM\Entity(repositoryClass="Tato\Bundle\PaymentBundle\Entity
    \CustomerOrderRepository")!
    */!
    class CustomerOrder!
    {!
    /**!
    * Set product!
    *!
    * @param \stdClass $product!
    * @return CustomerOrder!
    */!
    public function setProduct($product)!
    {!
    $this->product = $product;!
    !
    return $this;!
    }!
    . . .!
    }!
    !
    

    View Slide

15. %%%*&$% #
    /**!
    * Customer!
    *!
    * @ORM\Table()!
    * @ORM\Entity(repositoryClass="Tato\Bundle\PaymentBundle\Entity
    \CustomerRepository")!
    */!
    class Customer!
    {!
    /**!
    * @var integer!
    *!
    * @ORM\Column(name="id", type="integer")!
    * @ORM\Id!
    * @ORM\GeneratedValue(strategy="AUTO")!
    */!
    private $id;!
    !
    . . .!
    }!
    !
    

    View Slide

16. %#
    

    View Slide

17. % ###
    public function buyProduct(Product $product, Customer $customer, Money $moneyPayed)!
    {!
    $productPrice = $product->getPrice();!
    if ($moneyPayed->getCurrency() !== $productPrice->getCurrency()) {!
    throw new OrderException('The Currency of that payment is invalid');!
    }!
    !
    if ($moneyPayed->getPrice() !== $productPrice->getPrice()) {!
    throw new OrderException('You must pay me!');!
    }!
    !
    $conditions = $product->getConditions();!
    !
    foreach ($conditions as $condition) {!
    if (!$condition->isValid($customer)) {!
    throw new OrderException('You must meet the product requirements!');!
    }!
    }!
    !
    $goods = $product->getGoods();!
    foreach ($goods as $good) {!
    $good->give($customer);!
    }!
    }!
    

    View Slide

18. $#'
    
    %#
    #
    #! $%
    #*
    #
    $$ (
    $#'
    

    View Slide

19. THIS IS WAR!
    

    View Slide

20. BUT YOU WANT THIS
    

    View Slide

21. BUT WE WANT THIS
    TODAY
    YOU WILL GET THIS
    

    View Slide

22. %-$ #%$* *
    

    View Slide

23. %-$ #%$* *
    # %
    

    View Slide

24. ,
    $#
    ,
    ,
    !*%&
    ,
    ! %
    !*%
    &
    $%#&%
    

    View Slide

25. &$% #
    A CUSTOMER CAN ORDER A PRODUCT
    !
    A CUSTOMER CAN PAY AN ORDER
    

    View Slide

26. &$% #
    public function order(Product $product)!
    {!
    $order = new Order(rand(), $this, $product);!
    $this->recordThat(!
    new OrderCreated($order->getId(), $this->id, $product)!
    );!
    !
    return $order;!
    }!
    We are recording
    Events!
    

    View Slide

27. &$% #
    public function pay(Order $order, Money $money)!
    {!
    $status = $order->pay($money);!
    $this->recordThat(new OrderPaid($this->id, $order->getId(), $money));!
    if ($status === OrderStatus::ORDER_FAILED) {!
    $this->recordThat(new OrderFailed($order->getId(), $this->id));!
    }!
    if ($status === OrderStatus::ORDER_PAID) {!
    $this->recordThat(!
    new OrderPaid($order->getId(), $this->id, $money)!
    );!
    }!
    return $status;!
    }
    

    View Slide

28. ##
    AN ORDER MUST ENSURE THAT THEIR
    PRODUCT MEETS THEIR CONDITIONS
    !
    AN ORDER CAN BE PAID
    

    View Slide

29. ##
    public function __construct($id, Customer $customer, $product)!
    {!
    $this->id = $id;!
    $this->customer = $customer;!
    $this->status = new OrderStatus(OrderStatus::ORDER_STARTED);!
    $this->guardProductConditions($product);!
    $this->product = $product;!
    }
    Ensure that the product
    satisfies business conditions
    

    View Slide

30. public function pay(Money $money)!
    {!
    try {!
    if (!$this->product->getPrice()->isEqualTo($money)) {!
    throw new OrderException('The Order amount is not satisfied');!
    }!
    $this->product->deliver($this->customer);!
    $this->status = OrderStatus::create(OrderStatus::ORDER_PAID);!
    } catch (\Exception $e) {!
    $this->status = OrderStatus::create(OrderStatus::ORDER_FAILED);!
    }!
    return $this->status;!
    }
    ##
    Return what we need
    

    View Slide

31. (% &%#! $% #$
    

    View Slide

32. (% &%#! $% #$
    $(%
    

    View Slide

33. interface OrderRepository!
    {!
    public function orderExists($orderId);!
    !
    public function find($id, $customerId);!
    !
    public function findByCustomerId($customerId);!
    !
    public function save($id, $productId, $customerId, $status = 1);!
    !
    public function remove($id);!
    !
    public function removeByCustomerId($customerId);!
    !
    public function clearAll();!
    }!
    ##
    We provide an Interface
    

    View Slide

34. &%(#
    

    View Slide

35. &%(#
    % ###
    

    View Slide

36. View Slide

37. public function buyProductAction(Request $request)!
    {!
    $customer = new Customer($request->request->get('customerId'));!
    !
    $productRepository = $this->get('tato.payment.product_respository');!
    $product = $productRepository->find($request->request->get('productId'));!
    !
    $order = $customer->order($product);!
    !
    $paid = new Money(!
    $request->request->get('paid'), !
    $request->request->get(‘currency')!
    );!
    $status = $order->pay($paid);!
    !
    $this->get(‘tato.payment.order_repository')->save(!
    ! ! $order->getId(), !
    $product, !
    $customer->getId(), !
    $status->getStatus()!
    );!
    !
    return new JsonResponse(array('status' => $status->getStatus()));!
    }!
    }
    $* * %# #
    

    View Slide

38. %-$ #%$* *
    
    

    View Slide

39. TAKE A PIECE OF
    CQRS
    

    View Slide

40. public function handle(BuyProductCommand $command)!
    {!
    $customer = new Customer($command->customerId);!
    $product = $this->productRepository->find($command->productId);!
    !
    $order = $customer->order($product);!
    $status = $order->pay(new Money($command->paid, $command->currency));!
    !
    $events = $customer->getRecordedEvents();!
    !
    // @todo do something with this events!
    !
    $this->orderRepository->setOrder(!
    $command->gatewayName,!
    $order->getId(),!
    $command->customerId,!
    $status->getStatus()!
    );!
    !
    return $order;!
    }
    #
    We have Events!
    

    View Slide

41. class BuyProductCommand!
    {!
    public $customerId;!
    !
    public $productId;!
    !
    public $paid;!
    !
    public $currency;!
    !
    public function __construct($customerId, $productId, $paid, $currency)!
    {!
    $this->customerId = $customerId;!
    $this->productId = $productId;!
    $this->paid = $paid;!
    $this->currency = $currency;!
    } !
    }
    %
    A simple DTO
    

    View Slide

42. ! %
    
    

    View Slide

43. ('$
    An example of a Business requested feature
    based on a TRUE STORY
    Project file distribution
    The Domain Model
    Use of Domain Events
    Adapter for our component
    !
    Integrating in our Symfony Project
    

    View Slide

44. %%('
    ! %
    

    View Slide

45. $%#&%
    
    $#
    ,
    ,
    !*%&
    ,
    ! %
    !*%
    &
    

    View Slide

46. (!&%$$$ #
    %#!%% $
    

    View Slide

47. ###! $% #*
    !
    class CustomOrderRepository extends EntityRepository implements
    OrderRepository!
    {!
    . . .!
    !
    /**!
    * Checks if an order already exists.!
    *!
    * @param int $orderId!
    * @return bool!
    * @throws \Tato\Component\Payment\Exception\Order
    \OrderRepositoryException!
    */!
    public function orderExists($orderId)!
    {!
    ! ! ! $order = $this->entityManager->find('Order:Order', $orderId);!
    !
    return $order instanceof Order;!
    }!
    !
    . . . !
    }
    DOCTRINE!
    

    View Slide

48. $#'$
    services:!
    tato.payment.order_repository:!
    class: Tato\Component\Game\CustomOrderRepository!
    arguments:!
    - @doctrine.orm.entity_manager!
    !
    tato.payment.product_repository:!
    class: Tato\Component\Game\Product\CustomProductRepository!
    arguments:!
    - @doctrine.orm.entity_manager!
    !
    tato.payment.command.handler.buy_product:!
    class: Tato\Component\Payment\Command\BuyProductCommandHandler!
    arguments:!
    order_repository: @tato.payment.order_repository!
    product_repository: @tato.payment.product_repository!
    

    View Slide

49. %#!!
    doctrine:!
    orm:!
    auto_generate_proxy_classes: "%kernel.debug%"!
    auto_mapping: false!
    mappings:!
    Order:!
    type: yml!
    is_bundle: false!
    dir: %kernel.root_dir%/../src/Tato/Bundle/PaymentBundle/
    Resources/config/doctrine!
    prefix: Tato\Component\Payment\Order!
    alias: PaymentOrder
    %%!+$& (% $% # %#%%$ &%$ $* *&
    

    View Slide

50. %$$%!
    

    View Slide

51. %$$%!
    %%#*! %
    

    View Slide

52. !*% %# #
    public function buyProductAction(Request $request)!
    {!
    $customerId = $request->request->get('customerId');!
    $productId = $request->request->get('productId');!
    $paid = $request->request->get('paid');!
    $currency = $request->request->get('currency');!
    $command = new BuyProductCommand(!
    $customerId, !
    $productId, !
    $paid, !
    $currency!
    );!
    $commandHandler = $this->get('tato.payment.command.handler.buy_product');!
    $order = $commandHandler->handle($command);!
    $events = $order->getRecordedEvents();!
    // @todo do something wit this events!
    return new JsonResponse(array('status' => $order->getStatus()));!
    }
    

    View Slide

53. public function buyProductAction(Request $request)!
    {!
    $customer = new Customer($request->request->get('customerId'));!
    !
    $productRepository = $this->get('tato.payment.product_respository');!
    $product = $productRepository->find($request->request->get('productId'));!
    !
    $order = $customer->order($product);!
    !
    $paid = new Money(!
    $request->request->get('paid'), !
    $request->request->get(‘currency')!
    );!
    $status = $order->pay($paid);!
    !
    $this->get(‘tato.payment.order_repository')->save(!
    ! ! $order->getId(), !
    $product, !
    $customer->getId(), !
    $status->getStatus()!
    );!
    !
    return new JsonResponse(array('status' => $status->getStatus()));!
    }!
    }
    %#$%!!#
    Business Specification
    in a Controller
    Coupled to Symfony DIC
    

    View Slide

54. #%%
    
    
    
    REPOSITORIES
    DIC
    &
    ADAPTERS
    
    *%$
    #( #
    

    View Slide

55. BE HEXAGONAL!
    

    View Slide

56. ENJOY DDD
    

    View Slide

57. $ %#$%
    http://buttercup-php.github.io/protects
    http://vaughnvernon.co
    http://dddinphp.org
    http://domainlanguage.com/ddd/patterns/DDD_Reference_2011-01-31.pdf
    http://ebookbrowsee.net/domain-driven-design-step-by-step-pdf-d322892202
    http://martinfowler.com/bliki/CQRS.html
    http://www.amazon.es/Domain-Driven-Design-Tackling-Complexity-Software/dp/
    0321125215
    http://www.amazon.com/Implementing-Domain-Driven-Design-Vaughn-Vernon/
    dp/0321834577
    

    View Slide

58. "&$% $
    

    View Slide

59. Sergio Moya @soyelsergillo
    %$
    -
    

    View Slide