Using API platform to build ticketing system Antonio Perić-Mažar, Locastic 22.11.2019. - #SymfonyCon, Amsterdam

Antonio Perić-Mažar CEO @ Locastic Co-founder @ Litto Co-founder @ Tinel Meetup t: @antonioperic m: antonio@locastic.com

Locastic Helping clients create web and mobile apps since 2011 • UX/UI • Mobile apps • Web apps • Training & Consulting www.locastic.com @locastic

• 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 & API Platform Experience

• Social network • chat based • matching similar to Tinder :) • few CRM/ERP applications Context & API Platform Experience

What is API platform ?

–Fabien Potencier (creator of Symfony), SymfonyCon 2017 “API Platform is the most advanced API platform, in any framework or language.”

• 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

• 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:

• 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:

• invalidation-based HTTP caching • and basically everything needed to build modern APIs. API Platform built-in features:

Creating Simple CRUD in a minute

Create Entity Step One id; } }

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

Add Validation Step Three # config/validator/greeting.yaml App\Entity\Greeting: properties: name: - NotBlank: ~

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

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Serialization Groups Read Write

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Use YAML Configuration advice

User Management & Security

• Avoid using FOSUserBundle • not well suited with API • to much overhead and not needed complexity • Use Doctrine User Provider • simple and easy to integrate • bin/console maker:user User management

// 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 … }

// 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

// 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']

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(); }

• 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)

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• 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

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User security checker Security 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('...'); } } }

User security checker Security # config/packages/security.yaml # ... security: firewalls: main: pattern: ^/ user_checker: App\Security\UserChecker # ...

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'

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)'

• 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 or your custom Provider). JWT tip A database-less user provider

JWT tip A database-less user provider # config/packages/security.yaml security: providers: jwt: lexik_jwt: ~ security: firewalls: api: provider: jwt guard: # ...

Creating multi-language APIs

• 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

getTranslation()->setTitle($title); return $this; } public function getTitle() { return $this->getTranslation()->getTitle(); } }

title = $title; return $this; } public function getTitle() { return $this->title; } }

title = $title; return $this; } public function getTitle() { return $this->title; } } AppBundle\Entity\Post: itemOperations: get: method: GET put: method: PUT normalization_context: groups: ['translations'] collectionOperations: get: method: GET post: method: POST normalization_context: groups: ['translations'] attributes: filters: ['translation.groups'] normalization_context: groups: ['post_read'] denormalization_context: groups: ['post_write']

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" } } }

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!" }

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" } } }

• https://github.com/lexik/LexikTranslationBundle • or you can write your own: • https://locastic.com/blog/symfony-translation-process- automation/ Static translation

Manipulating context and avoding to have / api/admin

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; // ... }

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

// 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; } }

Symfony Messenger Component

• 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

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• 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

CQRS Symfony Messenger & API Platform App\Entity\PasswordResetRequest: collectionOperations: post: status: 202 itemOperations: [] attributes: messenger: true output: false

CQRS Symfony Messenger & API Platform

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())); } }

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())); } }

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• If same Symfony application is dispatching and consuming messages it works very well • If different Symfony applications are consuming messages, there are issues • If Symfony applications consume some 3-rd party non-Symfony messages, there is huge issue Symfony & Messenger

{ "body":"{\"key\":\"TESTING\",\"variables\":{\"UserName\":\"some test username \", \"Greetings\":\"Some test greeting 4faf188d396e99e023a3f77c04a9c06d\",\"Email\": \"antonio@locastic.com\"},\"to\":\"antonio@locastic.com\"}", "properties":[ ], "headers":{ "type":"App\\Message\\CommunicationMessage", "X-Message-Stamp-Symfony\\Component\\Messenger\\Stamp\ \BusNameStamp":"[{\"busName\":\"command_bus\"}]", "X-Message-Stamp-Symfony\\Component\\Messenger\\Stamp\ \SentStamp":"[{\"senderClass\":\"Enqueue\\\\MessengerAdapter\\\\QueueInteropTransport\", \"senderAlias\":\"communication_sync_amqp\"}]", "Content-Type":"application\/json" } }

{ "body":"{\"key\":\"TESTING\",\"variables\":{\"UserName\":\"some test username \", \"Greetings\":\"Some test greeting 4faf188d396e99e023a3f77c04a9c06d\",\"Email\": \"antonio@locastic.com\"},\"to\":\"antonio@locastic.com\"}", "properties":[ ], "headers":{ "type":"App\\Message\\CommunicationMessage", "X-Message-Stamp-Symfony\\Component\\Messenger\\Stamp\ \BusNameStamp":"[{\"busName\":\"command_bus\"}]", "X-Message-Stamp-Symfony\\Component\\Messenger\\Stamp\ \SentStamp":"[{\"senderClass\":\"Enqueue\\\\MessengerAdapter\\\\QueueInteropTransport\", \"senderAlias\":\"communication_sync_amqp\"}]", "Content-Type":"application\/json" } }

{ "body":"{\"key\":\"TESTING\",\"variables\":{\"UserName\":\"some test username \", \"Greetings\":\"Some test greeting 4faf188d396e99e023a3f77c04a9c06d\",\"Email\": \"antonio@locastic.com\"},\"to\":\"antonio@locastic.com\"}", "properties":[ ], "headers":{ "type":"App\\Message\\CommunicationMessage", "X-Message-Stamp-Symfony\\Component\\Messenger\\Stamp\ \BusNameStamp":"[{\"busName\":\"command_bus\"}]", "X-Message-Stamp-Symfony\\Component\\Messenger\\Stamp\ \SentStamp":"[{\"senderClass\":\"Enqueue\\\\MessengerAdapter\\\\QueueInteropTransport\", \"senderAlias\":\"communication_sync_amqp\"}]", "Content-Type":"application\/json" } } String contains escaped JSON

{ "key": "TESTING", "variables": { "username": "some test userName", "Grettings": "Some test greeting 4faf188d396e99e023a3f77c04a9c06d", "Email:" "antonio@locastic.com" } }

namespace App\Messenger; … class ExternalJsonMessageSerializer implements SerializerInterface { public function decode(array $encodedEnvelope): Envelope { $body = $encodedEnvelope['variables']; $headers = $encodedEnvelope['key']; $data = json_decode($body, true); if (null === $data) { throw new MessageDecodingFailedException('Invalid JSON'); } if (!isset($headers['type'])) { throw new MessageDecodingFailedException('Missing "type" header'); } if ($headers !== 'TESTING') { throw new MessageDecodingFailedException(sprintf('Invalid type "%s"', $headers)); } // in case of redelivery, unserialize any stamps $stamps = []; if (isset($headers['stamps'])) { $stamps = unserialize($headers['stamps']); } $envelope = $this->createMyExternalMessage($data); // in case of redelivery, unserialize any stamps $stamps = []; if (isset($headers['stamps'])) { $stamps = unserialize($headers['stamps']); } $envelope = $envelope->with(... $stamps); return $envelope; } … }

namespace App\Messenger; … class ExternalJsonMessageSerializer implements SerializerInterface { public function decode(array $encodedEnvelope): Envelope { $body = $encodedEnvelope['variables']; $headers = $encodedEnvelope['key']; $data = json_decode($body, true); if (null === $data) { throw new MessageDecodingFailedException('Invalid JSON'); } if (!isset($headers['type'])) { throw new MessageDecodingFailedException('Missing "type" header'); } if ($headers !== 'TESTING') { throw new MessageDecodingFailedException(sprintf('Invalid type "%s"', $headers)); } // in case of redelivery, unserialize any stamps $stamps = []; if (isset($headers['stamps'])) { $stamps = unserialize($headers['stamps']); } $envelope = $this->createMyExternalMessage($data); // in case of redelivery, unserialize any stamps $stamps = []; if (isset($headers['stamps'])) { $stamps = unserialize($headers['stamps']); } $envelope = $envelope->with(... $stamps); return $envelope; } … } private function createMyExternalMessage($data): Envelope { $message = new MyExternalMessage($data); $envelope = new Envelope($message); // needed only if you need this to be sent through the non-default bus $envelope = $envelope->with(new BusNameStamp('command.bus')); return $envelope; }

namespace App\Messenger; … class ExternalJsonMessageSerializer implements SerializerInterface { public function decode(array $encodedEnvelope): Envelope { $body = $encodedEnvelope['variables']; $headers = $encodedEnvelope['key']; $data = json_decode($body, true); if (null === $data) { throw new MessageDecodingFailedException('Invalid JSON'); } if (!isset($headers['type'])) { throw new MessageDecodingFailedException('Missing "type" header'); } if ($headers !== 'TESTING') { throw new MessageDecodingFailedException(sprintf('Invalid type "%s"', $headers)); } // in case of redelivery, unserialize any stamps $stamps = []; if (isset($headers['stamps'])) { $stamps = unserialize($headers['stamps']); } $envelope = $this->createMyExternalMessage($data); // in case of redelivery, unserialize any stamps $stamps = []; if (isset($headers['stamps'])) { $stamps = unserialize($headers['stamps']); } $envelope = $envelope->with(... $stamps); return $envelope; } … } private function createMyExternalMessage($data): Envelope { $message = new MyExternalMessage($data); $envelope = new Envelope($message); // needed only if you need this to be sent through the non-default bus $envelope = $envelope->with(new BusNameStamp('command.bus')); return $envelope; } framework: messenger: ... transports: ... # a transport used consuming messages from an external system # messages are not meant to be *sent* to this transport external_messages: dsn: '%env(MESSENGER_TRANSPORT_DSN)%' serializer: App\Messenger\ExternalJsonMessageSerializer options: # assume some other system will create this auto_setup: false # exchange config not needed because that's only # for *sending* messages queues: messages_from_external: ~ ...

• https://github.com/Happyr/message-serializer (custom serializer) • http://developer.happyr.com/symfony-messenger-on-aws-lambda • have in mind that Messenger component is similar to ORM • will work in most of cases but in same situation you will need to do custom/your own solution More help:

Handling emails

• Symfony Mailer component • load balancer • /w messenger component can do async in easy way • high availability / failover • Amazon SES, Gmail, Mailchim Mandril, Mailgun, Postmark, Sendgrid Handling emails

Creating reports (exports)

• problem: • different objects from source and in our database • multiple sources of data (3rd party) • DataTransformer transforms from source object to our object (DTO) • exporting to CSV files Using DTOs with import and export

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']

setOrderNumber($data->getOrderNumber()); if ($data->getStatus() instanceof Status) { $export->setOrderStatus($data->getStatus()->getStatus()); } $export->setOrderDate($data->getOrderDate()); … … $export->setTotalNumberOfTicketsInOrder($data->getTickets()->count()); $export->setTicketRevenue($data->getTicketsRevenue()->getFormatted()); $export->setDeliveryStatus($data->getDeliveryStatus()->getStatus()); $export->setDeliveryMethodRevenue($data->getDeliveryCost()->getFormatted()); $export->setFeeRevenue($data->getTotalFees()->getFormatted()); $export->setTicketTypes($data->getTicketTypesFormatted()); return $export; } /** * {@inheritdoc} */ public function supportsTransformation($data, string $to, array $context = []): bool { return OrderExport::class === $to && $data instanceof Order; } }

Real-time applications with API platform

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

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• 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.rocks

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)); }

Testing

• 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

Handy testing tools

• Created for PHPUnit • Manipulates the Symfony HttpKernel directly to simulate HTTP requests and responses • Huge performance boost compared to triggering real network requests • Also good to consider Sylius/ApiTestCase The test Http Client in API Platform

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PHP Matcher Library that enables you to check your response against patterns.

PHP Matcher Library that enables you to check your response against patterns.

Faker (/w Alice) Library for generating random data

Postman tests Newman + Postman

Postman tests + Newman Newman + Postman

• 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

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Api Platform (Symfony) is awesome! Conclusion

Thank you!

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