Hexagonal Architecture

Transcript

1. Hexagonal Architecture Chris Fidao (hek-sag-uh-nl)

2. @fideloper

3. None

4. Implementing Laravel Real-world implementation of testable and maintainable code. (hopefully)

5. Vaprobash Vagrant Provisioning Bash Scripts

6. Servers for Hackers.com

7. Why / What Ports / Adapters Boundary Layers /

8. WHY Architecture

9. Maintainability Technical Debt Time

10. What is it?

11. So…What is it?

12. The Hexagon Core Domain Application Domain Framework

13. (Core) Domain Core Domain Application Domain Framework

14. Behavior

15. Constraints

16. Application Core Domain Application Domain Framework

17. Framework Core Domain Application Domain Framework

18. Outside Core Domain Application Domain Framework

19. Ports Adapters /

20. Ports & Adapters Core Domain Application Domain Framework

21. Inside/Outside Core Domain Application Domain CommandBus Framework HTTP Use Case

    Repo DBAL Database Events Dispatcher Service Impl

22. Core Domain Application Domain Framework Dependencies

23. interface Notifier { ! public function send(Message $message); } class

    SesNotifier implements Notifier { ! public function send(Message $message) { // Details } }

24. Use-Case Driven Development

25. All the Contexts •Web •API •CLI •Queue •Event Handler

26. Use Cases: CommandBus CommandBus executes( ) Command Handler handles( )

    Command

27. // Class SimpleCommandBus ! public function execute( $command ) {

    return $this->getHandler( $command ) ->handle( $command ); } Simple CommandBus

28. Core Domain Application Domain CommandBus Framework HTTP Use Case Repo

    DBAL Database Events Dispatcher Service Impl
29. None

30. Boundaries

31. Domain/Application Boundary Core Domain Application Domain Framework Use Case Repo

    Events

32. interface CommandBusInterface { ! public function execute( $command ); }

    interface HandlerInterface { ! public function handle( $command ); }

33. Core Domain Application Domain Framework Use Case Repo Events

34. interface TicketRepositoryInterface { ! public function getStaffOpenTickets( Staffer $staffer, $limit=10);

    ! ! public function save(Ticket $model); }

35. Application Domain CommandBus Framework DBAL Dispatcher The Application/External Boundary

36. interface Notifier { ! public function send(Message $message); } interface

    Validator { ! public function passes(Array $data); ! public function getErrors(); } interface Dispatcher { ! public function dispatch(Array $events); }

37. Framework Core Domain Application Domain Framework HTTP Database Service Impl

38. Identify the aspects that vary and separate them from what

    stays the same

39. Layers

40. The Domain Core Domain Application Domain Framework Use Case Repo

    Events

41. <?php namespace Hex\Tickets; ! class Ticket extends Model { !

    public function assignStaffer(Staffer $staffer) { if( ! $staffer->categories->contains( $this->category ) ) { throw new DomainException("Staffer can't be assigned to ".$this->category); } ! $this->staffer()->associate($staffer); // Set Relationship ! return $this; } ! public function setCategory(Category $category) { if( $this->staffer instanceof Staffer && ! $this->staffer->categories->contains( $category ) ) { // Unset staffer if can't be assigned to set category $this->staffer = null; } ! $this->category()->associate($category); // Set Relationship ! return $this; } }

42. class Ticket extends Model { ! /* ... Other logic

    ... */ ! public function save(array $options = array()) { /* Integrity Checks, and then: */ ! if( ! $this->exists ) { $this->raise( new TicketCreatedEvent($this) ); } ! return parent::save($options); } }

43. class CreateTicketCommand { ! protected $data; ! public function __construct($data)

    { $this->data = $data; } ! public function __get($property) { // Simplified example return $this->data[$property]; } }

44. The Application Application Domain CommandBus Framework DBAL Dispatcher

45. // Class SimpleCommandBus ! public function execute( $command ) {

    return $this->getHandler( $command ) ->handle( $command ); }

46. ! class CreateTicketHandler implements HandlerInterface { ! ! public function

    handle($command) { $this->validate($command); // Throw ValidationException $this->save($command); } ! protected function save($command) { $ticket = new Ticket; /* Some other setters... */ $ticket->setCategory( $this->catRepo->find($command->category_id) ); $ticket->setStaffer( $this->staffRepo->find($command->staffer_id) ); $ticket->addMessage( $ticket->addMessage($command->message); ); ! $this->ticketRepo->save($ticket); // Use Repositories ! $this->dispatcher->dispatch( $ticket->flushEvents() ); // Fire Events } }

47. class DbTicketRepository implements RepositoryInterface { ! public function getStaffOpenTickets(Staffer $staffer,

    $limit=10) { return $this->ticket->where('staff_id', $staffer->id) ->take($limit)->get(); } ! public function save(Ticket $ticket) { $ticket->save(); } }

48. Framework Core Domain Application Domain Framework HTTP Database Service Impl

49. class TicketController extends BaseController { ! public function createTicket() {

    $command = new CreateTicketCommand( Input::all() ); ! try { $this->bus->execute($command); } catch(ValidationException $e) { return Redirect::to('/tickets/new') ->withErrors( $e->getErrors() ); } catch(DomainException $e) { return Redirect::to('/tickets/new') ->withErrors( $e->getErrors() ); } return Redirect::to(‘/tickets'); } }

50. class SesEmailNotifier implements NotifierInterface { ! public function __construct(SesClient $client)

    { $this->client = $client; } ! public function send(Message $message) { $to = [$message->to()]; $message = ['Data' => $message->message()]; ! $this->client->sendEmail([ 'Destination' => ['ToAddresses' => $to], 'Message' => ['Body' => ['Html' => $message]] ]); } }

51. use Illuminate\Events\Dispatcher as EventDispatcher; ! class LaravelDispatcher implements Dispatcher {

    ! public function __construct(EventDispatcher $dispatcher) { $this->dispatcher = $dispatcher; } ! public function dispatch(Array $events) { foreach( $events as $event ) { $this->dispatcher->fire( $event->name(), $event ); } } ! }

52. TDD is DEAD (and other myths)

53. Identify the aspects that vary and separate them from what

    stays the same

54. Thanks