Domain-driven Design in PHP and Symfony - Drupal Camp Wroclaw!
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The document discusses Domain-Driven Design (DDD) in the context of PHP and Symfony, emphasizing its principles for managing complex software development by focusing on core domains and establishing a collaborative, shared language. It outlines design strategies, architecture, and programming constructs needed for implementing DDD effectively, including the use of aggregates, repositories, and services. Ultimately, it advocates building software that is adaptable to continuous change while harnessing domain knowledge through structured patterns and practices.
Domain-driven Design in PHP and Symfony - Drupal Camp Wroclaw!
- 1. Domain-Driven Design in PHP & Symfony
- 2. Kacper Gunia @cakper Software Engineer @SensioLabsUK Symfony Certified Developer PHPers Silesia @PHPersPL
- 6. How to tackle it?
- 7. Domain-Driven Design is ! an approach to the development of complex software in which we: –Eric Evans
- 8. 1. Focus on the core domain. –Eric Evans
- 9. 2. Explore model in ! a creative collaboration of domain practitioners and software practitioners. –Eric Evans
- 10. 3. Speak an ubiquitous language within an explicitly bounded context. –Eric Evans
- 11. When to use DDD?
- 12. Complex domain
- 13. Domain Experts
- 16. Strategic DDD
- 17. Strategy! ! Stratos - army/resources! Ago - leading
- 18. Strategy! ! ! = What
- 19. Bounded Context
- 20. Bounded contexts of product ❖ Catalogue! ❖ Sales! ❖Marketing! ❖Warehouse
- 22. Core Domain
- 26. UI SERVICE UNIT
- 27. Refactoring Towards Deeper Insight
- 28. Tactical DDD
- 29. Tactics! ! Taktike - the art of organising an army, a maneuver
- 30. Tactics! ! ! = How
- 31. Building Blocks
- 33. USER INTERFACE APPLICATION DOMAIN INFRASTRUCTURE
- 34. . └── src └── Dcwroc ├── Shopping ├── Emejzon ├── EmejzonBundle └── DoctrineAdapter
- 35. Entities
- 36. class Sale { (…) private $id; ! function __construct($name, DateTimeInterface $dueDate) { $this-‐>name = $name; $this-‐>dueDate = $dueDate; } ! public function getId() { return $this-‐>id; } }
- 37. class Sale { (…) public function activate() { if (true === $this-‐>active) { throw new LogicException('Sale already activated!'); } ! $this-‐>active = true; } }
- 38. Value objects
- 39. class Email { (…) public function __construct($email) { if (!filter_var($email, FILTER_VALIDATE_EMAIL)) { throw new InvalidArgumentException(); } ! $this-‐>email = $email; } ! function asString() { return $this-‐>email; } }
- 40. Aggregates
- 41. class Order {(…) function __construct( Customer $customer, ProductList $productList ){ $this-‐>customer = $customer; $this-‐>productList = $productList; $this-‐>status = Status::open(); } ! public function getTotal(); }
- 42. Repositories
- 43. interface OrderRepository { public function save(Order $order); ! public function remove(Order $order); public function findById($orderId); ! public function findObsolete(); }
- 44. class DoctrineOrderRepository implements OrderRepository {} ! class FileOrderRepository implements OrderRepository {} ! class InMemoryOrderRepository implements OrderRepository {}
- 45. Factories
- 46. class CustomerFactory { public function register(Email $email, Password $password) { (...) ! return $customer; } }
- 47. Services
- 48. interface Notifier { public function send(Message $message); }
- 49. class EmailNotifier implements Notifier { private $mailer; ! function __construct(Swift_Mailer $mailer) { $this-‐>mailer = $mailer; } ! public function send(Message $message) { (…) } }
- 50. Domain Events
- 51. class ResetPassword { function request(Email $email) { $user = $this-‐>userRepository-‐>findOneByEmail($email); ! if (!$user instanceof User) { return $this-‐>raise(new UserDoesNotExistEvent($email)); } ! $request = Password::requestReset($user); $this-‐>passwordResetRequestRepository-‐>save($request); $this-‐>raise(new RequestIssuedEvent($request)); } }
- 52. class ResetPassword { function request(Email $email) { $user = $this-‐>userRepository-‐>findOneByEmail($email); ! if (!$user instanceof User) { return $this-‐>raise(new UserDoesNotExistEvent($email)); } ! $request = Password::requestReset($user); $this-‐>passwordResetRequestRepository-‐>save($request); $this-‐>raise(new RequestIssuedEvent($request)); } }
- 53. class ResetPassword { function request(Email $email) { $user = $this-‐>userRepository-‐>findOneByEmail($email); ! if (!$user instanceof User) { return $this-‐>raise(new UserDoesNotExistEvent($email)); } ! $request = Password::requestReset($user); $this-‐>passwordResetRequestRepository-‐>save($request); $this-‐>raise(new RequestIssuedEvent($request)); } }
- 54. class ResetPassword { function request(Email $email) { $user = $this-‐>userRepository-‐>findOneByEmail($email); ! if (!$user instanceof User) { return $this-‐>raise(new UserDoesNotExistEvent($email)); } ! $request = Password::requestReset($user); $this-‐>passwordResetRequestRepository-‐>save($request); $this-‐>raise(new RequestIssuedEvent($request)); } }
- 55. Modules
- 56. . └── Shopping └── Authentication ├── InvalidPasswordResetRequest.php ├── ResetPassword.php ├── PasswordResetRequest.php └── PasswordResetRequestRepository.php
- 57. Supple Design
- 61. Create software other developers want to work with
- 63. Domain model is always in a valid state
- 64. Command Pattern
- 65. class ChangeEmailCommand { public $email; public $customerId; }
- 66. class ChangeEmailCommandHandler { private $customerRepository; ! function __construct(CustomerRepository $customerRepository) { $this-‐>customerRepository = $customerRepository; } ! public function handle(ChangeEmailCommand $command) { $customer = $this-‐>customerRepository -‐>findById($command-‐>customerId); $customer-‐>changeEmail($command-‐>email); } }
- 68. interface Specification { public function isSatisfiedBy($object); }
- 69. class PayingCustomerSpecification implements Specification { public function isSatisfiedBy($object) { return $object instanceof Customer && $object-‐>getAmountSpent() > 0.0; } }
- 70. class FreeDeliveryCalculator { private $specification; ! function __construct(Specification $specification) { $this-‐>specification = $specification; } ! public function applyDiscount(Order $order) { $customer = $this-‐>$order-‐>getCustomer(); if ($this-‐>specification-‐>isSatisfiedBy($customer)) { $order-‐>deliverForFree(); } } }
- 71. class FreeDeliveryCalculator { private $specification; ! function __construct(Specification $specification) { $this-‐>specification = $specification; } ! public function applyDiscount(Order $order) { $customer = $this-‐>$order-‐>getCustomer(); if ($this-‐>specification-‐>isSatisfiedBy($customer)) { $order-‐>deliverForFree(); } } }
- 73. Commands
- 74. Use ORM to fetch/save aggregate roots
- 75. Queries
- 76. Use specialised queries and DTO’s to fetch presentation data
- 77. DDD Summary
- 80. By speaking Ubiquitous Language
- 81. Make use of Building Blocks
- 82. By applying Object-Oriented Design
- 84. That’s the only constant!
- 85. “In order to create good software, you have to know what that software is all about.” –Eric Evans
- 86. Kacper Gunia Software Engineer Thanks! Symfony Certified Developer PHPers Silesia