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.

Transcript

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
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: ~
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)
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
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
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
65. • Redis + NodeJS • Pusher • ReactPHP • … • but to be honest PHP is not build for realtime :) Real-time applications with API platform
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
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