Enable highend SPAs using REST-APIs with Symfony 4

This talk describes how to prototype an API using Symfony 4's event cycle and introduces API Platform as a way for a production ready API built on top of the same concepts.

Transcript

1. ENABLE HIGHEND SINGLE PAGE APPLICATIONS USING REST-APIS
 WITH SYMFONY 4 & FLEX
2. DENIS BRUMANN denis.brumann@sensiolabs.de @dbrumann
4. $kernel = new Kernel($env, $debug); $request = Request::createFromGlobals(); $response = $kernel->handle($request); $response->send();
5. Request Response call controller
6. /** * @Route("/", name="catalog") */ public function showAction(): Response { $products = $this->getDoctrine()
 ->getRepository(Product::class)
 ->findAll(); return $this->render( 'catalog/show.html.twig', [ 'products' => $products, ] ); }
7. /** * @Route("/", name="catalog") */ public function showAction(): Response { $products = $this->getDoctrine()
 ->getRepository(Product::class)
 ->findAll(); return $this->render( 'catalog/show.html.twig', [ 'products' => $products, ] ); }
8. /** * @Route("/products", name="products") * @Method("GET") */ public function listProducts() { return $this->getDoctrine()
 ->getRepository(Product::class)
 ->findAll(); }
9. /** * @Route("/products", name="products") * @Method("GET") */ public function listProducts() { return $this->getDoctrine()
 ->getRepository(Product::class)
 ->findAll(); } !❗
13. Request Response call controller kernel.
 view
14. interface EventSubscriberInterface { public static function getSubscribedEvents(); }
15. public static function getSubscribedEvents() { return [ 'kernel.view' => 'onKernelView', ]; }
16. public function onKernelView(
 GetResponseForControllerResultEvent $event
 ) { $products = $event->getControllerResult(); $response = new JsonResponse($products); $event->setResponse($response); }
17. class JsonResponseHandler implements EventSubscriberInterface { public static function getSubscribedEvents() { return [ KernelEvents::VIEW => 'onKernelView', ]; } public function onKernelView(
 GetResponseForControllerResultEvent $event
 ) { $data = $event->getControllerResult(); $response = new JsonResponse($data); if ($data === null) { $response->setStatusCode(
 JsonResponse::HTTP_NO_CONTENT
 ); } $event->setResponse($response); } }
19. /** * @Route("/products/{id}", name="product_show") * @Method("GET") */ public function getProduct(int $id) { $product = $this->getDoctrine() ->getRepository(Product::class) ->find($id); if (!$product) { throw new NotFoundHttpException('...'); } return $product; }
21. Request Response call controller kernel.
 exception Exception
22. public static function getSubscribedEvents() { return [ 'kernel.exception' => 'myMethod', ]; }
23. $request = $event->getRequest(); if (strpos($request->getPathInfo(), '/api/') !== 0) { return; } $exception = $event->getException(); $error = [ 'type' => $this->detectErrorType($exception), // Warning! Passing the message is insecure! 'message' => $exception->getMessage(), ]; $response = new JsonResponse(
 $error,
 $this->detectStatusCode($exception)
 ); $event->setResponse($response);
27. /** * @Route("/products", name="products_create") * @Method("POST") */ public function createProduct(Product $product) { $manager = $this->getDoctrine()->getManager(); $manager->persist($product); $manager->flush(); return new JsonResponse( null, JsonResponse::HTTP_CREATED ); }
28. curl -i http://localhost:8000/api/products -X "POST" -H "Content-Type: application/json" -d '{"name": "Mystery Box", "price": 3999}'
29. Request Response call controller kernel.
 view kernel.
 exception Exception resolve arguments
30. interface ArgumentValueResolverInterface { /** * Whether this resolver can resolve the value for the given
 * ArgumentMetadata. * * @param Request $request * @param ArgumentMetadata $argument * * @return bool */ public function supports(Request $request, ArgumentMetadata $argument); /** * Returns the possible value(s). * * @param Request $request * @param ArgumentMetadata $argument * * @return \Generator */ public function resolve(Request $request, ArgumentMetadata $argument); }
31. public function supports(
 Request $request,
 ArgumentMetadata $argument
 ) { return ( strpos($request->getPathInfo(), '/api/') === 0 && $argument->getType() === Product:class && !empty($request->getContent()) ); }
32. public function resolve(Request $request, ArgumentMetadata $argument) { $data = $this->serializer->deserialize( $request->getContent(), $argument->getType(), 'json' ); $errors = $this->validator->validate($data, null, $groups); if (count($errors)) { throw new BadRequestHttpException((string) $errors); } yield $data; }
34. Request Response kernel.
 request kernel.
 response kernel.
 controller kernel.
 exception resolve controller call controller kernel.
 terminate Exception resolve arguments kernel.
 view SYMFONY KERNEL EVENTS
36. SYMFONY 4 BENEFITS No changes to services.yaml were needed! Only 1 added dependency (orm-pack) Small build artefact due to fewer dependencies
38. PRODUCTION SETUP WITH
 API-PLATFORM
40. COMPOSER REQUIRE API
42. <?php namespace App\Entity; use ApiPlatform\Core\Annotation\ApiResource; use Doctrine\ORM\Mapping as ORM; use Symfony\Component\Validator\Constraints as Assert; /** * @ApiResource * @ORM\Entity */ class Rollercoaster { /** * @ORM\Id() * @ORM\GeneratedValue * @ORM\Column(type="integer") */ public $id; // ... }
43. <?php namespace App\Entity; use ApiPlatform\Core\Annotation\ApiResource; use Doctrine\ORM\Mapping as ORM; use Symfony\Component\Validator\Constraints as Assert; /** * @ApiResource * @ORM\Entity */ class Rollercoaster { /** * @ORM\Id() * @ORM\GeneratedValue * @ORM\Column(type="integer") */ public $id; // ... }
46. FEATURES Builds a fully featured API with JSON-LD, Hydra & GraphQL Auto-generated documentation with Swagger or Open API Authentication with JWT or OAuth HTTP Caching, CORS-support, schema.org-data model
48. Questions?
49. Thanks!