Divide and Conquer (LonghornPHP 2019)

Transcript

1. Divide And Conquer
   LonghornPHP 2019
   May 04 2019
   Austin,TX
   Andreas Hucks
   

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2. @meandmymonkey
   Andreas Hucks
   SensioLabs
   

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3. Motivation
   

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4. What this talk is not about:
   • DDD
   • Generic Package Design
   

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5. A Generic Framework App
   

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9. /**

   * @Route(path="/", name="list")

   */

   public function index()

   {

   $robots = $this

   ->getDoctrine()

   ->getRepository(Robot::class)

   ->findAll()

   ;

   

   return $this->render(

   'robot/index.html.twig',

   [

   'robots' => $robots

   ]

   );

   }
   

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10. /**

    * @Route(path="/{id}", name="edit")

    */

    public function edit(Request $request, Robot $robot)

    {

    $form = $this->createForm(RobotType::class, $robot);

    $form->handleRequest($request);

    

    if ($form->isSubmitted() && $form->isValid()) {

    $this->getDoctrine()->getManager()->flush();

    

    return $this->redirectToRoute('list');

    }
    

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11. /**

    * @ORM\Entity(repositoryClass="…")

    * @ORM\Table(name="robots")

    */

    class Robot

    {

    public static $propusionTypes = [

    'legs' => 'Can walk',

    'wheels' => 'Drives',

    'tracks' => 'Tracked Vehicle',

    'jetpack' => 'Hovers',

    'weird' => 'Why would you build that'

    ];

    

    /**

    * @ORM\Column(type=“integer")

    * @ORM\Id()

    * @ORM\GeneratedValue()

    */

    private $id;
    

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12. public function validatePropulsion(
    ExecutionContextInterface $context,
    $payload
    ) {

    if (!in_array($this->getPropulsion(), self::$propusions)) {

    

    }

    }
    

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13. namespace App\Entity;

    

    use Doctrine\ORM\Mapping as ORM;

    use Symfony\Component\Security\Core\User\UserInterface;

    use Symfony\Component\Validator\Constraints as Assert;

    

    /**

    * @ORM\Entity()

    * @ORM\Table(name="mechanics")

    */

    class Mechanic implements UserInterface

    {

    // …
    

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14. The Problem
    

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16. Dependencies of your Code
    • to Validator
    • to Doctrine
    • to Security Layer
    • To the FrameworkBundle
    

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17. Direct Access to Entities
    • from View
    • in Forms
    

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18. Other Concerns
    • Mixing responsibilities
    • Controller uses Doctrine directly
    

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19. Why Separate?
    

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20. Clean Layers
    • Separate your business code from your framework
    • … or in fact, any other 3rd party libs
    • Separate your own layers/packages (Domain,
    Application, Infrastructure…)
    

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21. Architecture Patterns
    !
    

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22. Extracting the Domain
    

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24. Dedicated Top Level
    Namespaces?
    !
    

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28. Domain\Entity\Robot:

    type: entity

    table: robots

    repositoryClass: Domain\Repository\RobotRepository

    id:

    id:

    type: uuid

    length: 255

    fields:

    name:

    type: string

    length: 255

    nullable: false

    […]

    embedded:

    propulsion:

    class: Domain\Entity\Data\Propulsion

    columnPrefix: false
    

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29. public function __construct($value)

    {

    $propulsion = (string) $value;

    

    if (!in_array($propulsion, array_keys(self::$propusions))) {

    throw new Exception('Invalid key');

    }

    

    $this->propulsion = $propulsion;

    }
    

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30. Domain\Entity\Data\Propulsion:

    type: embeddable

    fields:

    propulsion:

    type: string

    length: 255

    nullable: false
    

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32. class Id

    {

    private $key;

    

    public function __construct($key)

    {

    $this->key = (string) $key;

    }

    

    public function getKey()

    {

    return $this->key;

    }
    

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33. dbal:

    types:

    uuid:

    class: Domain\Doctrine\Type\Uuid

    commented: true
    

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34. 

    class Uuid extends Type

    {

    public function convertToDatabaseValue($value, AbstractPlatform $platform)

    {

    if (empty($value)) {

    return null;

    }

    

    if ($value instanceof Id) {

    return $value->getKey();

    }

    

    return null;

    }

    

    

    

    public function getSQLDeclaration(array $fieldDeclaration, AbstractPlatform
    $platform)

    {

    return 'VARCHAR(255) COMMENT \'(DC2Type:uuid)\'';

    }

    

    public function getName()

    {

    return 'uuid';

    }

    }
    

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36. class InvalidPropulsionException
    extends \InvalidArgumentException
    implements RobotException
    {
    }
    

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37. Deptrac
    • github.com/sensiolabs-de/deptrac
    

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40. layers:
    - name: Application
    collectors:
    - type: className
    regex: ^App\\Controller\\.*|App\\Form\\.*|\\App\\Kernel
    - name: Domain
    collectors:
    - type: className
    regex: ^App\\Domain\\.*
    - name: Framework
    collectors:
    - type: className
    regex: ^Symfony\\|Doctrine\\.*
    ruleset:
    Application:
    - Domain
    - Framework
    Application:
    - Domain
    

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43. Sidetrack: How Symfony
    Packages Compare
    

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46. Extracting Infrastructure
    

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49. namespace App\Domain\Repository;

    

    use App\Domain\Entity\Data\Id;

    use App\Domain\Entity\Robot;
    interface RobotRepository

    {

    public function get(Id $id);

    

    public function add(Robot $robot);
    // […]

    }
    

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50. Naming…
    RobotRepository
    vs.
    RobotRespositoryInterface
    !
    

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51. namespace App\Infrastructure\Doctrine\Repository;

    

    use Doctrine\ORM\EntityRepository;

    use Domain\Entity\Data\Id;

    use Domain\Entity\Robot;

    use Domain\Repository\RobotRepository as RepositoryInterface;
    class RobotRepository extends EntityRepository implements RepositoryInterface

    {

    public function get(Id $id)

    {

    return $this->findOneBy(['id' => $id]);

    }

    

    public function add(Robot $robot)

    {

    $this->_em->persist($robot);

    $this->_em->flush($robot);

    }

    }
    

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52. Extending
    EntityRepository?
    !
    

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55. Decoupling Security
    

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56. namespace App\Domain\Entity;

    

    use Doctrine\ORM\Mapping as ORM;

    use Symfony\Component\Security\Core\User\UserInterface;

    use Symfony\Component\Validator\Constraints as Assert;

    

    /**

    * @ORM\Entity()

    * @ORM\Table(name="mechanics")

    */

    class Mechanic implements UserInterface

    {

    // …
    

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57. 

    interface UserProviderInterface

    {

    public function loadUserByUsername($username);

    

    public function refreshUser(UserInterface $user);

    

    public function supportsClass($class);

    }

    

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59. class MechanicAccount implements UserInterface

    {

    private $mechanicId;

    private $username;

    private $password;

    

    public static function fromMechanic(Mechanic $mechanic)

    {

    $account = new static();

    

    $account->mechanicId = $mechanic->getId();

    $account->username = $mechanic->getEmail();

    $account->password = $mechanic->getPassword();

    

    return $account;

    }
    

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60. public function loadUserByUsername($username)

    {

    $mechanic = $this->repository

    ->findOneBy(['email' => new Email($username)]);

    

    if (null === $mechanic) {

    throw new UsernameNotFoundException(
    'User does not exist.'
    );

    }

    

    return MechanicAccount::fromMechanic($mechanic);

    }
    

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61. Validation, Forms,
    ViewModels
    

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62. class RobotUpdate

    {

    public $name;

    public $coolness;

    public $propulsion;

    }
    

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63. App\Domain\RobotUpdate:

    properties:

    name:

    - NotBlank: ~

    

    

    

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64. class RobotService

    {

    public function updateRobot(RobotUpdate $date, Robot $robot)

    {

    // ...

    }

    }
    

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65. public function configureOptions(OptionsResolver $resolver)

    {

    $resolver->setDefaults(array(

    'data_class' => ‘App\Domain\RobotUpdate'

    ));

    }
    

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66. Missing pieces
    

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67. Be pragmatic
    !
    

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68. Going further
    

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69. What about Controllers?
    !
    

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70. Thank you!
    

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71. Specification Pattern
    !
    

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