When Easy Is Hard

...and when hard is easy. Building great applications in PHP is easy - with frameworks like Symfony, Laravel, Yii - it is easier than ever. But the easier you try to make developing applications, the harder it becomes to keep developing one continuously. In my talk I will discuss what easy and hard means at different stages of the project and how we
can make it easier for ourselves to deliver software that matters.

Transcript

1. WHEN EASY IS HARD 15 June 2015
2. Marek Matulka Software Engineer at SensioLabsUK @super_marek
4. http://london2015.live.symfony.com/
5. Take it easy!
6. Framework
8. Convenience
10. © http://www.yiiframework.com/tour/
11. <?php namespace App\Http\Controllers; use App\Http\Controllers\Controller; class UserController extends Controller { /** * Show the profile for the given user. * * @param int $id * @return Response */ public function showProfile($id) { return view('user.profile', ['user' => User::findOrFail($id)]); } }
12. <?php namespace Acme\ConferenceBundle\Controller; use Symfony\Bundle\FrameworkBundle\Controller\Controller; use Symfony\Component\HttpFoundation\Response; class RegistrationController extends Controller { public function registerAction($id) { $conference = $this->getDoctrine() ->getRepository('AcmeConferenceBundle:Conference') ->find($id); $this->get('acme_conference.enrolment.service') ->enrol($conference, $this->getUser())) { return new Response('Success!'); } }
13. Cost
14. price speed quality
15. © http://the-language-corner.com/noticias/wp-content/uploads/2015/01/academia-ingl%C3%A9s-en-Madrid.jpg Phase 1 completed!
16. Let’s grow!
17. New features
18. <?php namespace Acme\ConferenceBundle\Controller; use Symfony\Bundle\FrameworkBundle\Controller\Controller; class RegistrationController extends Controller { public function registerAction($id) { $conference = $this->getDoctrine() ->getRepository('AcmeConferenceBundle:Conference')->find($id); if ( $enrolment = $this->get('acme_conference.enrolment.service') ->enrol($conference, $this->getUser()) ) { $em = $this->getDoctrine()->getEntityManager(); $em->persist($enrolment); $em->flush(); $this->get('acme_conference.notification.service') ->notify($this->getUser(), 'success'); return $this->redirect('registration_successful') } return $this->redirect('registration_failed'); } } © http://warrenmars.com/
20. © http://www.smosh.com/smosh-pit/memes/20-best-i-didnt-choose-thug-life-memes
21. Yummy spaghetti code! © http://momeefriendsli.com/2013/04/16/dinner-and-a-book/
22. …and there are no tests!
23. No one wants to touch it
24. Let’s rewrite it!
26. not so happy customer © https://channelinstincts.files.wordpress.com/2014/01/unhappy-customer.jpg
27. price speed quality
28. price speed sustainability
29. What has happened?
30. What has happened? - too close to the framework
31. What has happened? - too close to the framework - no separation of concerns
32. What has happened? - too close to the framework - no separation of concerns - mixed layers
33. What has happened? - too close to the framework - no separation of concerns - mixed layers - no tests!
34. delivered features time Features delivered over time
35. How to avoid?
36. Forget the framework!
37. Decouple your code
38. Decoupled code - improves readability
39. Decoupled code - improves readability - can be reused
40. Decoupled code - improves readability - can be reused - easy to maintain
41. Decoupled code - improves readability - can be reused - easy to maintain - easy to change
42. Let’s do it!
43. Global scope is a smell! Avoid hidden dependencies
44. class RegistrationController { public function registerAction($id) { $learner = Session::getUser(); $conference = Conference::findOrFail($id); Enrolment::enrolLearnerInConference($learner, $conference); Mail::send('emails.welcome', array('key' => 'value'), function($message) use ($learner, $conference) { $message->to($learner->email(), $learner->name()) ->subject('Thanks for registering for '.$conference->name().'!'); } ); } }
45. Inject only what you need
46. class RegistrationController { public function __construct( Enrolment $enrolment, Learner $learner, Notifier $notifier ) { $this->enrolment = $enrolment; $this->learner = $learner; $this->notifier = $notifier; } public function registerAction(Conference $conference) { $enrolment = $this->enrolment->enrolLearnerInConference($this->learner, $conference); $this->notifier->successfulEnrolment($enrolment); } }
47. Don’t mix layers
48. class RegistrationController { public function __construct( EnrolmentHandler $enrolmentHandler, Learner $learner ) { $this->enrolmentHandler = $enrolmentHandler; $this->learner = $learner; } public function registerAction(Conference $conference) { $this->enrolmentHandler->handle( new EnrolLearnerInConference($this->learner, $conference); ); } }
49. class RegistrationController { public function __construct( EnrolmentHandler $enrolmentHandler, Learner $learner ) { $this->enrolmentHandler = $enrolmentHandler; $this->learner = $learner; } public function registerAction(Conference $conference) { $this->enrolmentHandler->handle( new EnrolLearnerInConference($this->learner, $conference); ); } }
50. class RegistrationController { public function registerAction($id) { $learner = Session::getUser(); $conference = Conference::findOrFail($id); Enrolment::enrolLearnerInConference($learner, $conference); Mail::send('emails.welcome', array('key' => 'value'), function($message) use ($learner, $conference) { $message->to($learner->email(), $learner->name()) ->subject('Thanks for registering for '.$conference->name().'!'); } ); } }
51. class RegistrationController { public function __construct( EnrolmentHandler $enrolmentHandler, Learner $learner ) { $this->enrolmentHandler = $enrolmentHandler; $this->learner = $learner; } public function registerAction(Conference $conference) { $this->enrolmentHandler->handle( new EnrolLearnerInConference($this->learner, $conference); ); } }
52. class EnrolmentHandler { public function __construct(EnrolmentRepository $enrolmentRepository, Mailer $mailer) { $this->repository = $enrolmentRepository; $this->mailer = $mailer; } public function handle(EnrolLearnerInConference $enrolmentCommand) { $enrolment = $enrolmentCommand->execute(); $this->repository>save($enrolment); $this->mailer->send('emails.welcome', array('key' => 'value'), function($message) use ($enrolment) { $message->to($enrolment->learner()->email(), $enrolment->learner()->name()) ->subject('Thanks for registering for '.$enrolment->conference->name().'!'); }); }
53. Invert dependencies
54. class EnrolmentHandler { public function __construct(EnrolmentRepository $enrolmentRepository, Mailer $mailer) { $this->repository = $enrolmentRepository; $this->mailer = $mailer; } public function handle(EnrolLearnerInConference $enrolmentCommand) { $enrolment = $enrolmentCommand->execute(); $this->repository>save($enrolment); $this->mailer->send('emails.welcome', array('key' => 'value'), function($message) use ($enrolment) { $message->to($enrolment->learner()->email(), $enrolment->learner()->name()) ->subject('Thanks for registering for '.$enrolment->conference->name().'!'); }); }
55. class EnrolmentHandler { public function __construct( EnrolmentRepository $enrolmentRepository, EnrolmentNotifier $notifier ) { $this->repository = $enrolmentRepository; $this->notifier = $notifier; } public function handle(EnrolLearnerInConference $enrolmentCommand) { if ($enrolment = $enrolmentCommand->execute()) { $this->repository->save($enrolment); $this->notifier->successfulEnrolment($enrolment); } } }
56. interface EnrolmentNotifier { /** * @param Enrolment $enrolment * * @throws FaildToNotify */ public function successfulEnrolment(Enrolment $enrolment); }
57. interface EnrolmentRepository { /** * @param integer $id * @return Enrolment */ public function findOneById($id); /** * @param Enrolment $enrolment */ public function save(Enrolment $enrolment); }
58. EnrolmentRepository DoctrineEnrolmentRepository InMemoryEnrolmentRepositor y EntityManager Dependency Inversion InMemoryRepository
59. Clean Code
60. Layered Architecture
61. User Interface Application Domain Infrastructure
62. Clean Architecture by Robert C. Martin
63. Entities Use Cases Controllers UI
64. Entities Use Cases Controllers UI Framework Drivers Interface Adapters Application Business Rules Enterprise Business Rules
65. aka Ports & Adapters Hexagonal Architecture
66. UI Adapter Log Adapter Data Storage Adapter Domain External Data Adapter
67. UI Adapter Log Adapter Data Storage Adapter Domain External Data Adapter UI client port log adapter port persistence layer port data provider port
68. UI Adapter Monolog Test Adapter NullLogger Doctrine InMemory Domain Facebook API Mock API
69. class EnrolmentHandler { public function __construct( EnrolmentRepository $enrolmentRepository, EnrolmentNotifier $notifier ) { $this->repository = $enrolmentRepository; $this->notifier = $notifier; } public function handle(EnrolLearnerInConference $enrolmentCommand) { if ($enrolment = $enrolmentCommand->execute()) { $this->repository->save($enrolment); $this->notifier->successfulEnrolment($enrolment); } } }
70. interface EnrolmentRepository { /** * @param integer $id * * @return Enrolment */ public function findOneById($id); /** * @param Enrolment $enrolment */ public function save(Enrolment $enrolment); }
71. class DoctrineEnrolmentRepository implements EnrolmentRepository { public function __construct(EntityManager $entityManager) { $this->em = $entityManager; } public function findOneById($id) { return $this->em->find(Enrolment::class, $id); } public function save(Enrolment $enrolment) { $this->em->persist($enrolment); $this->em->flush($enrolment); } }
72. class InMemoryEnrolmentRepository implements EnrolmentRepository { public function __construct() { $this->repository = new InMemoryRepository(); } public function findOneById($id) { return $this->repository->findById($id); } public function save(Enrolment $enrolment) { $this->repository->save($enrolment); } }
73. (five more classes to write!) Hard!
75. Why bother?
76. Your Domain First
77. Domain models
78. Domain models Use Cases
79. Domain models Use Cases Controllers
80. Domain models Use Cases Commands Infrastructure
81. Clean Code!
82. Clean code - decoupled - reusable - testable - maintainable - changeable
83. Sustainable!
84. Easy! Adding new features?
85. delivered features time Features delivered over time
86. Recap
87. It’s your choice
88. and make the changes hard Start the easy way
89. and make the changes easy Start the hard way
90. “Everything is hard before it is easy” - Goethe
91. Questions?
92. Thank you! https://speakerdeck.com/super_marek @super_marek