Using API platform to build ticketing system (translations, time zones, ...)

Using API platform to build ticketing system (translations, time zones, ...)

Why is API platform a way to go and the new standard in developing apps? In this talk, I want to show you some real examples that we built using API platform including a ticketing system for the world’s biggest bicycle marathon and a social network that is a mixture of both Tinder and Facebook Messenger. We had to tackle problems regarding the implementation of tax laws in 18 different countries, dozens of translations (including Arabic), multiple role systems, different timezones, overall struggle with a complicated logic with an infinite number of branches, and more.

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Antonio Peric-Mazar

October 18, 2019
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  1. Using API platform to build ticketing system Antonio Perić-Mažar, Locastic

    Paula Čučuk, Locastic 18.10.2019. - #sfday
  2. Antonio Perić-Mažar CEO @ Locastic Co-founder @ Litto Co-founder @

    Tinel Meetup t: @antonioperic m: antonio@locastic.com
  3. Paula Čučuk Lead Backend Developer @ Locastic Partner @ Locastic

    t: @paulala_14 m: paula@locastic.com
  4. Locastic Helping clients create web and mobile apps since 2011

    • UX/UI • Mobile apps • Web apps • Training & Consulting www.locastic.com @locastic
  5. None
  6. • API Platform & Symfony • Ticketing platform: GFNY (franchise

    business) • ~ year and half in production • ~ 60 000 tickets released & race results stored in DB • ~ 20 000 users/racers, • ~ 60 users with admin roles • 48 events in 26 countries, users from 82 countries • 8 different languages including Hebrew and Indonesian Context & our Experience
  7. • Social network • chat based • matching similar to

    Tinder :) • few CRM/ERP applications Context & our Experience
  8. What is API platform ?

  9. –Fabien Potencier (creator of Symfony), SymfonyCon 2017 “API Platform is

    the most advanced API platform, in any framework or language.”
  10. • full stack framework dedicated to API-Driven projects • contains

    a PHP library to create a fully featured APIs supporting industry standards (JSON-LD, Hydra, GraphQL, OpenAPI…) • provides ambitious Javascript tooling to consume APIs in a snap • Symfony official API stack (instead of FOSRestBundle) • shipped with Docker and Kubernetes integration API Platform
  11. • creating, retrieving, updating and deleting (CRUD) resources • data

    validation • pagination • filtering • sorting • hypermedia/HATEOAS and content negotiation support (JSON-LD and Hydra, JSON:API, HAL…) API Platform built-in features:
  12. • GraphQL support • Nice UI and machine-readable documentations (Swagger

    UI/ OpenAPI, GraphiQL…) • authentication (Basic HTP, cookies as well as JWT and OAuth through extensions) • CORS headers • security checks and headers (tested against OWASP recommendations) API Platform built-in features:
  13. • invalidation-based HTTP caching • and basically everything needed to

    build modern APIs. API Platform built-in features:
  14. Creating Simple CRUD in a minute

  15. Create Entity Step One <?php // src/Entity/Greeting.php namespace App\Entity; class

    Greeting { private $id; public $name = ''; public function getId(): int { return $this->id; } }
  16. Create Mapping Step Two # config/doctrine/Greeting.orm.yml App\Entity\Greeting: type: entity table:

    greeting id: id: type: integer generator: { strategy: AUTO } fields: name: type: string length: 100
  17. Add Validation Step Three # config/validator/greeting.yaml App\Entity\Greeting: properties: name: -

    NotBlank: ~
  18. Expose Resource Step Four # config/api_platform/resources.yaml resources: App\Entity\Greeting: ~

  19. None
  20. None
  21. None
  22. None
  23. Serialization Groups

  24. User Management & Security

  25. • Avoid using FOSUserBundle • not well suited with API

    • Use Doctrine User Provider • simple and easy to integrate User management
  26. // src/Entity/User.php namespace App\Entity; use Symfony\Component\Security\Core\User\UserInterface; use Symfony\Component\Serializer\Annotation\Groups; class User

    implements UserInterface { /** * @Groups({"user-read"}) */ private $id; /** * @Groups({"user-write", "user-read"}) */ private $email; /** * @Groups({"user-read"}) */ private $roles = []; /** * @Groups({"user-write"}) */ private $plainPassword; private $password; … getters and setters … }
  27. // src/Entity/User.php namespace App\Entity; use Symfony\Component\Security\Core\User\UserInterface; use Symfony\Component\Serializer\Annotation\Groups; class User

    implements UserInterface { /** * @Groups({"user-read"}) */ private $id; /** * @Groups({"user-write", "user-read"}) */ private $email; /** * @Groups({"user-read"}) */ private $roles = []; /** * @Groups({"user-write"}) */ private $plainPassword; private $password; … getters and setters … } # config/doctrine/User.orm.yml App\Entity\User: type: entity table: users repositoryClass: App\Repository\UserRepository id: id: type: integer generator: { strategy: AUTO } fields: email: type: string length: 255 password: type: string length: 255 roles: type: array
  28. // src/Entity/User.php namespace App\Entity; use Symfony\Component\Security\Core\User\UserInterface; use Symfony\Component\Serializer\Annotation\Groups; class User

    implements UserInterface { /** * @Groups({"user-read"}) */ private $id; /** * @Groups({"user-write", "user-read"}) */ private $email; /** * @Groups({"user-read"}) */ private $roles = []; /** * @Groups({"user-write"}) */ private $plainPassword; private $password; … getters and setters … } # config/doctrine/User.orm.yml App\Entity\User: type: entity table: users repositoryClass: App\Repository\UserRepository id: id: type: integer generator: { strategy: AUTO } fields: email: type: string length: 255 password: type: string length: 255 roles: type: array # config/api_platform/resources.yaml resources: App\Entity\User: attributes: normalization_context: groups: ['user-read'] denormalization_context: groups: ['user-write']
  29. use ApiPlatform\Core\DataPersister\ContextAwareDataPersisterInterface; use App\Entity\User; use Doctrine\ORM\EntityManagerInterface; use Symfony\Component\Security\Core\Encoder\UserPasswordEncoderInterface; class UserDataPersister

    implements ContextAwareDataPersisterInterface { private $entityManager; private $userPasswordEncoder; public function __construct(EntityManagerInterface $entityManager, UserPasswordEncoderInterface $userPasswordEncoder) { $this->entityManager = $entityManager; $this->userPasswordEncoder = $userPasswordEncoder; } public function supports($data, array $context = []): bool { return $data instanceof User; } public function persist($data, array $context = []) { /** @var User $data */ if ($data->getPlainPassword()) { $data->setPassword( $this->userPasswordEncoder->encodePassword($data, $data->getPlainPassword()) ); $data->eraseCredentials(); } $this->entityManager->persist($data); $this->entityManager->flush($data); return $data; } public function remove($data, array $context = []) { $this->entityManager->remove($data); $this->entityManager->flush(); }
  30. • Lightweight and simple authentication system • Stateless: token signed

    and verified server-side then stored client- side and sent with each request in an Authorization header • Store the token in the browser local storage JSON Web Token (JWT)
  31. None
  32. None
  33. • API Platform allows to easily add a JWT-based authentication

    to your API using LexikJWTAuthenticationBundle. • Maybe you want to use a refresh token to renew your JWT. In this case you can check JWTRefreshTokenBundle. User authentication
  34. None
  35. User security checker Security <?php namespace App\Security; use App\Exception\AccountDeletedException; use

    App\Security\User as AppUser; use Symfony\Component\Security\Core\Exception\AccountExpiredException; use Symfony\Component\Security\Core\Exception\CustomUserMessageAuthenticat use Symfony\Component\Security\Core\User\UserCheckerInterface; use Symfony\Component\Security\Core\User\UserInterface; class UserChecker implements UserCheckerInterface { public function checkPreAuth(UserInterface $user) { if (!$user instanceof AppUser) { return; } // user is deleted, show a generic Account Not Found message. if ($user->isDeleted()) { throw new AccountDeletedException(); } } public function checkPostAuth(UserInterface $user) { if (!$user instanceof AppUser) { return; } // user account is expired, the user may be notified if ($user->isExpired()) { throw new AccountExpiredException('...'); } } }
  36. User security checker Security # config/packages/security.yaml # ... security: firewalls:

    main: pattern: ^/ user_checker: App\Security\UserChecker # ...
  37. Resource and operation level Security # api/config/api_platform/resources.yaml App\Entity\Book: attributes: security:

    'is_granted("ROLE_USER")' collectionOperations: get: ~ post: security: 'is_granted("ROLE_ADMIN")' itemOperations: get: ~ put: security_: 'is_granted("ROLE_ADMIN") or object.owner == user'
  38. Resource and operation level using Voters Security # api/config/api_platform/resources.yaml App\Entity\Book:

    itemOperations: get: security_: 'is_granted('READ', object)' put: security_: 'is_granted('UPDATE', object)'
  39. • A JWT is self-contained, meaning that we can trust

    into its payload for processing the authentication. In a nutshell, there should be no need for loading the user from the database when authenticating a JWT Token, the database should be hit only once for delivering the token. • It means you will have to fetch the User entity from the database yourself as needed (probably through the Doctrine EntityManager). JWT tip A database-less user provider
  40. JWT tip A database-less user provider # config/packages/security.yaml security: providers:

    jwt: lexik_jwt: ~ security: firewalls: api: provider: jwt guard: # ...
  41. Creating multi-language APIs

  42. • Locastic Api Translation Bundle • Translation bundle for ApiPlatform

    based on Sylius translation • It requires two entities: Translatable & Translation entity • Open source • https://github.com/Locastic/ApiPlatformTranslationBundle • https://locastic.com/blog/having-troubles-with-implementing- translations-in-apiplatform/ Creating multi-language APIs
  43. POST translation example Multi-language API { "datetime":"2017-10-10", "translations": { "en":{

    "title":"test", "content":"test", "locale":"en" }, "de":{ "title":"test de", "content":"test de", "locale":"de" } } }
  44. Get response by locale GET /api/posts/1?locale=en { "@context": "/api/v1/contexts/Post", "@id":

    "/api/v1/posts/1')", "@type": "Post", "id": 1, "datetime":"2019-10-10", "title":"Hello world", "content":"Hello from Verona!" }
  45. Get response with all translations GET /api/posts/1?groups[]=translations { "@context": "/api/v1/contexts/Post",

    "@id": "/api/v1/posts/1')", "@type": "Post", "id": 1, "datetime":"2019-10-10", "translations": { "en":{ "title":"Hello world", "content":"Hello from Verona!", "locale":"en" }, "it":{ "title":"Ciao mondo", "content":"Ciao da Verona!", "locale":"it" } } }
  46. • Endpoint for creating new language • Creates all Symfony

    translation files when new language is added • Endpoint for editing each language translation files Adding languages and translations dynamically
  47. Manipulating the Context Context namespace App\Entity; use ApiPlatform\Core\Annotation\ApiResource; use Symfony\Component\Serializer\Annotation\Groups;

    /** * @ApiResource( * normalizationContext={"groups"={"book:output"}}, * denormalizationContext={"groups"={"book:input"}} * ) */ class Book { // ... /** * This field can be managed only by an admin * * @var bool * * @Groups({"book:output", "admin:input"}) */ public $active = false; /** * This field can be managed by any user * * @var string * * @Groups({"book:output", "book:input"}) */ public $name; // ... }
  48. Manipulating the Context Context # api/config/services.yaml services: # ... 'App\Serializer\BookContextBuilder':

    decorates: 'api_platform.serializer.context_builder' arguments: [ '@App\Serializer\BookContextBuilder.inner' ] autoconfigure: false
  49. // api/src/Serializer/BookContextBuilder.php namespace App\Serializer; use ApiPlatform\Core\Serializer\SerializerContextBuilderInterface; use Symfony\Component\HttpFoundation\Request; use Symfony\Component\Security\Core\Authorization\AuthorizationCheckerInterface;

    use App\Entity\Book; final class BookContextBuilder implements SerializerContextBuilderInterface { private $decorated; private $authorizationChecker; public function __construct(SerializerContextBuilderInterface $decorated, AuthorizationCheckerInterface $authorizationChecker) { $this->decorated = $decorated; $this->authorizationChecker = $authorizationChecker; } public function createFromRequest(Request $request, bool $normalization, ?array $extractedAttributes = null): array { $context = $this->decorated->createFromRequest($request, $normalization, $extractedAttributes); $resourceClass = $context['resource_class'] ?? null; if ($resourceClass === Book::class && isset($context['groups']) && $this->authorizationChecker- >isGranted('ROLE_ADMIN') && false === $normalization) { $context['groups'][] = 'admin:input'; } return $context; } }
  50. Symfony Messanger Component

  51. • The Messenger component helps applications send and receive messages

    to/from other applications or via message queues. • Easy to implement • Making async easy • Many transports are supported to dispatch messages to async consumers, including RabbitMQ, Apache Kafka, Amazon SQS and Google Pub/Sub. Symfony Messenger
  52. None
  53. None
  54. • Allows to implement the Command Query Responsibility Segregation (CQRS)

    pattern in a convenient way. • It also makes it easy to send messages through the web API that will be consumed asynchronously. • Async import, export, image processing… any heavy work Symfony Messenger & API Platform
  55. CQRS Symfony Messenger & API Platform App\Entity\PasswordResetRequest: collectionOperations: post: status:

    202 itemOperations: [] attributes: messenger: true output: false
  56. CQRS Symfony Messenger & API Platform <?php namespace App\Handler; use

    App\Entity\PasswordResetRequest; use Symfony\Component\Messenger\Handler\MessageHandlerInterfac final class PasswordResetRequestHandler implements MessageHand { public function __invoke(PasswordResetRequest $forgotPassw { // do some heavy things } } <?php namespace App\Entity; final class PasswordResetRequest { public $email; }
  57. CQRS /w DTO Symfony Messenger & API Platform App\Entity\User: collectionOperations:

    post: status: 202 itemOperations: [] attributes: messenger: “input” input: “ResetPasswordRequest::class” output: false // api/src/Entity/User.php namespace App\Entity; use ApiPlatform\Core\Annotation\ApiResource; use App\Dto\ResetPasswordRequest; final class User { }
  58. CQRS /w DTO Symfony Messenger & API Platform // api/src/Handler/ResetPasswordRequestHandler.php

    namespace App\Handler; use App\Dto\ResetPasswordRequest; use Symfony\Component\Messenger\Handler\MessageHandlerInterface; final class ResetPasswordRequestHandler implements MessageHandle { public function __invoke(ResetPasswordRequest $forgotPasswor { // do something with the resource } } // api/src/Dto/ResetPasswordRequest.php namespace App\Dto; use Symfony\Component\Validator\Constraints as Assert; final class ResetPasswordRequest { public $var; }
  59. <?php namespace App\DataPersister; use ApiPlatform\Core\DataPersister\ContextAwareDataPersisterInterface; use App\Entity\ImageMedia; use Doctrine\ORM\EntityManagerInterface; use

    Symfony\Component\Messenger\MessageBusInterface; class ImageMediaDataPersister implements ContextAwareDataPersisterInterface { private $entityManager; private $messageBus; public function __construct(EntityManagerInterface $entityManager, MessageBusInterface $messageBus) { $this->entityManager = $entityManager; $this->messageBus = $messageBus; } public function supports($data, array $context = []): bool { return $data instanceof ImageMedia; } public function persist($data, array $context = []) { $this->entityManager->persist($data); $this->entityManager->flush($data); $this->messageBus->dispatch(new ProcessImageMessage($data->getId())); return $data; } public function remove($data, array $context = []) { $this->entityManager->remove($data); $this->entityManager->flush(); $this->messageBus->dispatch(new DeleteImageMessage($data->getId())); } }
  60. namespace App\EventSubscriber; use ApiPlatform\Core\EventListener\EventPriorities; use App\Entity\Book; use Symfony\Component\EventDispatcher\EventSubscriberInterface; use Symfony\Component\HttpFoundation\Request;

    use Symfony\Component\HttpKernel\Event\ViewEvent; use Symfony\Component\HttpKernel\KernelEvents; use Symfony\Component\Messenger\MessageBusInterface; final class BookMailSubscriber implements EventSubscriberInterface { private $messageBus; public function __construct(MessageBusInterface $messageBus) { $this->messageBus = $messageBus; } public static function getSubscribedEvents() { return [ KernelEvents::VIEW => ['sendMail', EventPriorities::POST_WRITE], ]; } public function sendMail(ViewEvent $event) { $book = $event->getControllerResult(); $method = $event->getRequest()->getMethod(); if (!$book instanceof Book || Request::METHOD_POST !== $method) { return; } // send to all users 2M that new book has arrived this->messageBus->dispatch(new SendEmailMessage(‘new-book’, $book->getTitle())); } }
  61. • problem: • different objects from source and in our

    database • multiple sources of data (3rd party) • DataTransform transforms from source object to our object • exporting to CSV files Using DTOs with import and export
  62. resources: App\Entity\Order: collectionOperations: get: ~ exports: method: POST path: '/orders/export'

    formats: csv: ['text/csv'] pagination_enabled: false output: "OrderExport::class" normalization_context: groups: ['order-export']
  63. Real-time applications with API platform

  64. None
  65. • Redis + NodeJS • Pusher • ReactPHP • …

    • but to be honest PHP is not build for realtime :) Real-time applications with API platform
  66. None
  67. • Fast, written in Go • native browser support, no

    lib nor SDK required (built on top of HTTP and server-sent events) • compatible with all existing servers, even those who don't support persistent connections (serverless architecture, PHP, FastCGI…) • Automatic HTTP/2 and HTTPS (using Let's Encrypt) support • CORS support, CSRF protection mechanism • Cloud Native, follows the Twelve-Factor App methodology • Open source (AGPL) • … Mercure
  68. resources: App\Entity\Greeting: attributes: mercure: true const eventSource = new EventSource('http://localhost:3000/hub?topic='

    + encodeURIComponent('http://example.com/greeting/1')); eventSource.onmessage = event => { // Will be called every time an update is published by the server console.log(JSON.parse(event.data)); }
  69. Testing

  70. None
  71. • Unit tests • test your logic, refactor your code

    using SOLID priciples • Integration tests • validation • 3rd party integrations • database queries • Functional tests • response code, header and content (expected fields in expected format) Type of tests
  72. • Ask yourself: “Am I sure the code I tested

    works as it should?” • 100% coverage doesn’t guarantee your code is fully tested and working • Write test first is just one of the approaches • Legacy code: • Start replicating bugs with tests before fixing them • Test at least most important and critical parts Testing tips and tricks
  73. Handy testing tools

  74. PHP Matcher Library that enables you to check your response

    against patterns.
  75. Faker Library for generating random data

  76. Postman tests Newman + Postman

  77. • Infection - tool for mutation testing • PHPStan -

    focuses on finding errors in your code without actually running it • Continuous integration (CI) -  enables you to run your tests on git on each commit Tools for checking test quality
  78. Api Platform is awesome! Conclusion

  79. Thank you!

  80. Questions? Antonio Perić-Mažar t: @antonioperic m: antonio@locastic.com Paula Čučuk t:

    @paulala_14 m: paula@locastic.com