feat(state): add headers to comply with LDP specification

src/Hydra/State/JsonStreamerProcessor.php

@@ -22,6 +22,7 @@
 use ApiPlatform\Metadata\IriConverterInterface;
 use ApiPlatform\Metadata\Operation;
 use ApiPlatform\Metadata\Operation\Factory\OperationMetadataFactoryInterface;
+use ApiPlatform\Metadata\Resource\Factory\ResourceMetadataCollectionFactoryInterface;
 use ApiPlatform\Metadata\ResourceClassResolverInterface;
 use ApiPlatform\Metadata\UrlGeneratorInterface;
 use ApiPlatform\State\Pagination\PaginatorInterface;
@@ -57,10 +58,12 @@ public function __construct(
         private readonly string $pageParameterName = 'page',
         private readonly string $enabledParameterName = 'pagination',
         private readonly int $urlGenerationStrategy = UrlGeneratorInterface::ABS_PATH,
+        ?ResourceMetadataCollectionFactoryInterface $resourceMetadataCollectionFactory = null,
     ) {
         $this->resourceClassResolver = $resourceClassResolver;
         $this->iriConverter = $iriConverter;
         $this->operationMetadataFactory = $operationMetadataFactory;
+        $this->resourceMetadataCollectionFactory = $resourceMetadataCollectionFactory;
     }
 
     public function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = [])

src/Laravel/ApiPlatformProvider.php

@@ -404,7 +404,13 @@ public function register(): void
         $this->app->bind(ProviderInterface::class, ContentNegotiationProvider::class);
 
         $this->app->singleton(RespondProcessor::class, function (Application $app) {
-            $decorated = new RespondProcessor();
+            $decorated = new RespondProcessor(
+                $app->make(IriConverterInterface::class),
+                $app->make(ResourceClassResolverInterface::class),
+                $app->make(OperationMetadataFactoryInterface::class),
+                $app->make(ResourceMetadataCollectionFactoryInterface::class)
+            );
+
             if (class_exists(AddHeadersProcessor::class)) {
                 /** @var ConfigRepository */
                 $config = $app['config']->get('api-platform.http_cache') ?? [];

src/Serializer/State/JsonStreamerProcessor.php

@@ -19,6 +19,7 @@
 use ApiPlatform\Metadata\IriConverterInterface;
 use ApiPlatform\Metadata\Operation;
 use ApiPlatform\Metadata\Operation\Factory\OperationMetadataFactoryInterface;
+use ApiPlatform\Metadata\Resource\Factory\ResourceMetadataCollectionFactoryInterface;
 use ApiPlatform\Metadata\ResourceClassResolverInterface;
 use ApiPlatform\State\ProcessorInterface;
 use ApiPlatform\State\Util\HttpResponseHeadersTrait;
@@ -46,10 +47,12 @@ public function __construct(
         ?IriConverterInterface $iriConverter = null,
         ?ResourceClassResolverInterface $resourceClassResolver = null,
         ?OperationMetadataFactoryInterface $operationMetadataFactory = null,
+        ?ResourceMetadataCollectionFactoryInterface $resourceMetadataCollectionFactory = null,
     ) {
         $this->resourceClassResolver = $resourceClassResolver;
         $this->iriConverter = $iriConverter;
         $this->operationMetadataFactory = $operationMetadataFactory;
+        $this->resourceMetadataCollectionFactory = $resourceMetadataCollectionFactory;
     }
 
     public function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = [])

src/State/Processor/RespondProcessor.php

@@ -17,6 +17,7 @@
 use ApiPlatform\Metadata\IriConverterInterface;
 use ApiPlatform\Metadata\Operation;
 use ApiPlatform\Metadata\Operation\Factory\OperationMetadataFactoryInterface;
+use ApiPlatform\Metadata\Resource\Factory\ResourceMetadataCollectionFactoryInterface;
 use ApiPlatform\Metadata\ResourceClassResolverInterface;
 use ApiPlatform\State\ProcessorInterface;
 use ApiPlatform\State\StopwatchAwareInterface;
@@ -40,10 +41,12 @@ public function __construct(
         ?IriConverterInterface $iriConverter = null,
         ?ResourceClassResolverInterface $resourceClassResolver = null,
         ?OperationMetadataFactoryInterface $operationMetadataFactory = null,
+        ?ResourceMetadataCollectionFactoryInterface $resourceMetadataCollectionFactory = null,
     ) {
         $this->iriConverter = $iriConverter;
         $this->resourceClassResolver = $resourceClassResolver;
         $this->operationMetadataFactory = $operationMetadataFactory;
+        $this->resourceMetadataCollectionFactory = $resourceMetadataCollectionFactory;
     }
 
     public function process(mixed $data, Operation $operation, array $uriVariables = [], array $context = [])

src/State/Tests/Fixtures/ApiResource/Dummy.php

@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\State\Tests\Fixtures\ApiResource;
+
+use ApiPlatform\Metadata\ApiResource;
+
+#[ApiResource()]
+class Dummy
+{
+    public int $id;
+}

src/State/Util/HttpResponseHeadersTrait.php

@@ -13,13 +13,16 @@
 
 namespace ApiPlatform\State\Util;
 
+use ApiPlatform\Metadata\Error;
 use ApiPlatform\Metadata\Exception\HttpExceptionInterface;
 use ApiPlatform\Metadata\Exception\InvalidArgumentException;
 use ApiPlatform\Metadata\Exception\ItemNotFoundException;
 use ApiPlatform\Metadata\Exception\RuntimeException;
 use ApiPlatform\Metadata\HttpOperation;
 use ApiPlatform\Metadata\IriConverterInterface;
 use ApiPlatform\Metadata\Operation\Factory\OperationMetadataFactoryInterface;
+use ApiPlatform\Metadata\Resource\Factory\ResourceMetadataCollectionFactoryInterface;
+use ApiPlatform\Metadata\ResourceClassResolverInterface;
 use ApiPlatform\Metadata\UrlGeneratorInterface;
 use ApiPlatform\Metadata\Util\ClassInfoTrait;
 use ApiPlatform\Metadata\Util\CloneTrait;
@@ -38,6 +41,8 @@ trait HttpResponseHeadersTrait
     use CloneTrait;
     private ?IriConverterInterface $iriConverter;
     private ?OperationMetadataFactoryInterface $operationMetadataFactory;
+    private ?ResourceClassResolverInterface $resourceClassResolver;
+    private ?ResourceMetadataCollectionFactoryInterface $resourceMetadataCollectionFactory;
 
     /**
      * @param array<string, mixed> $context
@@ -122,6 +127,41 @@ private function getHeaders(Request $request, HttpOperation $operation, array $c
             }
         }
 
+        if (
+            !$operation instanceof Error
+            && $operation->getUriTemplate()
+            && $this->resourceClassResolver?->isResourceClass($operation->getClass())
+        ) {
+            $this->addLinkedDataPlatformHeaders($headers, $operation);
+        }
+
         return $headers;
     }
+
+    private function addLinkedDataPlatformHeaders(array &$headers, HttpOperation $operation): void
+    {
+        if (!$this->resourceMetadataCollectionFactory) {
+            return;
+        }
+
+        $acceptPost = null;
+        $allowedMethods = ['OPTIONS', 'HEAD'];
+        $resourceCollection = $this->resourceMetadataCollectionFactory->create($operation->getClass());
+        foreach ($resourceCollection as $resource) {
+            foreach ($resource->getOperations() as $op) {
+                if ($op->getUriTemplate() === $operation->getUriTemplate()) {
+                    $allowedMethods[] = $method = $op->getMethod();
+                    if ('POST' === $method && \is_array($outputFormats = $op->getOutputFormats())) {
+                        $acceptPost = implode(', ', array_merge(...array_values($outputFormats)));
+                    }
+                }
+            }
+        }
+
+        if ($acceptPost) {
+            $headers['Accept-Post'] = $acceptPost;
+        }
+
+        $headers['Allow'] = implode(', ', $allowedMethods);
+    }
 }

src/Symfony/Bundle/Resources/config/json_streamer/events.php

@@ -26,6 +26,7 @@
             '%api_platform.collection.pagination.page_parameter_name%',
             '%api_platform.collection.pagination.enabled_parameter_name%',
             '%api_platform.url_generation_strategy%',
+            service('api_platform.metadata.resource.metadata_collection_factory'),
         ]);
 
     $services->set('api_platform.jsonld.state_provider.json_streamer', 'ApiPlatform\Hydra\State\JsonStreamerProvider')
@@ -41,6 +42,7 @@
             service('api_platform.iri_converter'),
             service('api_platform.resource_class_resolver'),
             service('api_platform.metadata.operation.metadata_factory'),
+            service('api_platform.metadata.resource.metadata_collection_factory'),
         ]);
 
     $services->set('api_platform.state_provider.json_streamer', 'ApiPlatform\Serializer\State\JsonStreamerProvider')

src/Symfony/Bundle/Resources/config/json_streamer/hydra.php

@@ -27,6 +27,7 @@
             '%api_platform.collection.pagination.page_parameter_name%',
             '%api_platform.collection.pagination.enabled_parameter_name%',
             '%api_platform.url_generation_strategy%',
+            service('api_platform.metadata.resource.metadata_collection_factory'),
         ]);
 
     $services->set('api_platform.jsonld.state_provider.json_streamer', 'ApiPlatform\Hydra\State\JsonStreamerProvider')

src/Symfony/Bundle/Resources/config/json_streamer/json.php

@@ -24,6 +24,7 @@
             service('api_platform.iri_converter'),
             service('api_platform.resource_class_resolver'),
             service('api_platform.metadata.operation.metadata_factory'),
+            service('api_platform.metadata.resource.metadata_collection_factory'),
         ]);
 
     $services->set('api_platform.state_provider.json_streamer', 'ApiPlatform\Serializer\State\JsonStreamerProvider')

src/Symfony/Bundle/Resources/config/state/processor.php

@@ -38,6 +38,7 @@
             service('api_platform.iri_converter'),
             service('api_platform.resource_class_resolver'),
             service('api_platform.metadata.operation.metadata_factory'),
+            service('api_platform.metadata.resource.metadata_collection_factory'),
         ]);
 
     $services->set('api_platform.state_processor.add_link_header', 'ApiPlatform\State\Processor\AddLinkHeaderProcessor')

src/Symfony/Bundle/Resources/config/symfony/events.php

@@ -84,6 +84,7 @@
             service('api_platform.iri_converter'),
             service('api_platform.resource_class_resolver'),
             service('api_platform.metadata.operation.metadata_factory'),
+            service('api_platform.metadata.resource.metadata_collection_factory'),
         ]);
 
     $services->set('api_platform.state_processor.add_link_header', 'ApiPlatform\State\Processor\AddLinkHeaderProcessor')

tests/Fixtures/TestBundle/ApiResource/DummyGetPostDeleteOperation.php

@@ -0,0 +1,66 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\Tests\Fixtures\TestBundle\ApiResource;
+
+use ApiPlatform\Metadata\ApiResource;
+use ApiPlatform\Metadata\Delete;
+use ApiPlatform\Metadata\Get;
+use ApiPlatform\Metadata\GetCollection;
+use ApiPlatform\Metadata\Operation;
+use ApiPlatform\Metadata\Post;
+
+#[ApiResource(operations: [
+    new Get(
+        uriTemplate: '/dummy_get_post_delete_operations/{id}',
+        provider: [self::class, 'provideItem'],
+    ),
+    new GetCollection(
+        uriTemplate: '/dummy_get_post_delete_operations',
+        provider: [self::class, 'provide'],
+    ),
+    new Post(
+        uriTemplate: '/dummy_get_post_delete_operations',
+        provider: [self::class, 'provide'],
+    ),
+    new Delete(
+        uriTemplate: '/dummy_get_post_delete_operations/{id}',
+        provider: [self::class, 'provideItem'],
+    ),
+])]
+class DummyGetPostDeleteOperation
+{
+    public ?int $id;
+
+    public ?string $name = null;
+
+    public static function provide(Operation $operation, array $uriVariables = [], array $context = []): array
+    {
+        $dummyResource = new self();
+        $dummyResource->id = 1;
+        $dummyResource->name = 'Dummy name';
+
+        return [
+            $dummyResource,
+        ];
+    }
+
+    public static function provideItem(Operation $operation, array $uriVariables = [], array $context = []): self
+    {
+        $dummyResource = new self();
+        $dummyResource->id = $uriVariables['id'];
+        $dummyResource->name = 'Dummy name';
+
+        return $dummyResource;
+    }
+}

tests/Functional/LinkedDataPlatformTest.php

@@ -0,0 +1,78 @@
+<?php
+
+/*
+ * This file is part of the API Platform project.
+ *
+ * (c) Kévin Dunglas <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+declare(strict_types=1);
+
+namespace ApiPlatform\Tests\Functional;
+
+use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
+use ApiPlatform\Tests\Fixtures\TestBundle\ApiResource\DummyGetPostDeleteOperation;
+use ApiPlatform\Tests\SetupClassResourcesTrait;
+
+class LinkedDataPlatformTest extends ApiTestCase
+{
+    use SetupClassResourcesTrait;
+
+    protected static ?bool $alwaysBootKernel = false;
+
+    /**
+     * @return class-string[]
+     */
+    public static function getResources(): array
+    {
+        return [DummyGetPostDeleteOperation::class];
+    }
+
+    public function testAllowHeadersForResourceCollectionReflectsAllowedMethods(): void
+    {
+        $client = static::createClient();
+        $client->request('GET', '/dummy_get_post_delete_operations', [
+            'headers' => [
+                'Content-Type' => 'application/ld+json',
+            ],
+        ]);
+
+        $this->assertResponseHeaderSame('allow', 'OPTIONS, HEAD, GET, POST');
+
+        $client = static::createClient();
+        $client->request('GET', '/dummy_get_post_delete_operations/1', [
+            'headers' => [
+                'Content-Type' => 'application/ld+json',
+            ],
+        ]);
+
+        $this->assertResponseHeaderSame('allow', 'OPTIONS, HEAD, GET, DELETE');
+    }
+
+    public function testAcceptPostHeaderForResourceWithPostReflectsAllowedTypes(): void
+    {
+        $client = static::createClient();
+        $client->request('GET', '/dummy_get_post_delete_operations', [
+            'headers' => [
+                'Content-Type' => 'application/ld+json',
+            ],
+        ]);
+
+        $this->assertResponseHeaderSame('accept-post', 'application/ld+json, application/hal+json, application/vnd.api+json, application/xml, text/xml, application/json, text/html, application/graphql, multipart/form-data');
+    }
+
+    public function testAcceptPostHeaderDoesNotExistForResourceWithoutPost(): void
+    {
+        $client = static::createClient();
+        $client->request('GET', '/dummy_get_post_delete_operations/1', [
+            'headers' => [
+                'Content-Type' => 'application/ld+json',
+            ],
+        ]);
+
+        $this->assertResponseNotHasHeader('accept-post');
+    }
+}