Add headers to media entities (#72)

* Add media headers

* Add and fix up tests

* Rebase and code review

* Remove ?_format=jsonld from edit-media link

islandora.services.yml

@@ -18,6 +18,11 @@ services:
     arguments: ['@entity_type.manager', '@current_user']
     tags:
       - { name: event_subscriber }
+  islandora.media_link_header_subscriber:
+    class: Drupal\islandora\EventSubscriber\MediaLinkHeaderSubscriber
+    arguments: ['@entity_field.manager', '@current_route_match', '@entity_type.manager']
+    tags:
+      - { name: event_subscriber }
   islandora.node_link_header_subscriber:
     class: Drupal\islandora\EventSubscriber\NodeLinkHeaderSubscriber
     arguments: ['@entity_field.manager', '@current_route_match']

src/EventSubscriber/LinkHeaderSubscriber.php

@@ -0,0 +1,124 @@
+<?php
+
+namespace Drupal\islandora\EventSubscriber;
+
+use Drupal\Core\Entity\EntityFieldManager;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+/**
+ * Class LinkHeaderSubscriber.
+ *
+ * @package Drupal\islandora\EventSubscriber
+ */
+abstract class LinkHeaderSubscriber implements EventSubscriberInterface {
+
+  /**
+   * The entity field manager.
+   *
+   * @var \Drupal\Core\Entity\EntityFieldManager
+   */
+  protected $entityFieldManager;
+
+  /**
+   * The route match object.
+   *
+   * @var \Drupal\Core\Routing\RouteMatchInterface
+   */
+  protected $routeMatch;
+
+  /**
+   * Constructor.
+   *
+   * @param \Drupal\Core\Entity\EntityFieldManager $entity_field_manager
+   *   The entity field manager.
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match object.
+   */
+  public function __construct(
+    EntityFieldManager $entity_field_manager,
+    RouteMatchInterface $route_match
+  ) {
+    $this->entityFieldManager = $entity_field_manager;
+    $this->routeMatch = $route_match;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    // Run this early so the headers get cached.
+    $events[KernelEvents::RESPONSE][] = ['onResponse', 129];
+
+    return $events;
+  }
+
+  /**
+   * Get the Node | Media | File.
+   *
+   * @param \Symfony\Component\HttpFoundation\Response $response
+   *   The current response object.
+   * @param string $object_type
+   *   The type of entity to look for.
+   *
+   * @return Drupal\Core\Entity\ContentEntityBase|bool
+   *   A node or media entity or FALSE if we should skip out.
+   */
+  protected function getObject(Response $response, $object_type) {
+    if ($object_type != 'node'
+      && $object_type != 'media'
+    ) {
+      return FALSE;
+    }
+
+    // Exit early if the response is already cached.
+    if ($response->headers->get('X-Drupal-Dynamic-Cache') == 'HIT') {
+      return FALSE;
+    }
+
+    if (!$response->isOk()) {
+      return FALSE;
+    }
+
+    // Hack the node out of the route.
+    $route_object = $this->routeMatch->getRouteObject();
+    if (!$route_object) {
+      return FALSE;
+    }
+
+    $methods = $route_object->getMethods();
+    $is_get = in_array('GET', $methods);
+    $is_head = in_array('HEAD', $methods);
+    if (!($is_get || $is_head)) {
+      return FALSE;
+    }
+
+    $route_contexts = $route_object->getOption('parameters');
+    if (!$route_contexts) {
+      return FALSE;
+    }
+    if (!isset($route_contexts[$object_type])) {
+      return FALSE;
+    }
+
+    $object = $this->routeMatch->getParameter($object_type);
+
+    if (!$object) {
+      return FALSE;
+    }
+
+    return $object;
+  }
+
+  /**
+   * Adds resource-specific link headers to appropriate responses.
+   *
+   * @param \Symfony\Component\HttpKernel\Event\FilterResponseEvent $event
+   *   Event containing the response.
+   */
+  abstract public function onResponse(FilterResponseEvent $event);
+
+}

src/EventSubscriber/MediaLinkHeaderSubscriber.php

@@ -0,0 +1,96 @@
+<?php
+
+namespace Drupal\islandora\EventSubscriber;
+
+use Drupal\Core\Entity\EntityFieldManager;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Routing\RouteMatchInterface;
+use Drupal\Core\Url;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
+
+/**
+ * Class MediaLinkHeaderSubscriber.
+ *
+ * @package Drupal\islandora\EventSubscriber
+ */
+class MediaLinkHeaderSubscriber extends LinkHeaderSubscriber implements EventSubscriberInterface {
+
+  /**
+   * Media storage interface.
+   *
+   * @var \Drupal\Core\Entity\EntityStorageInterface
+   */
+  protected $mediaBundleStorage;
+
+  /**
+   * MediaLinkHeaderSubscriber constructor.
+   *
+   * @param \Drupal\Core\Entity\EntityFieldManager $entity_field_manager
+   *   The entity field manager.
+   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
+   *   The route match object.
+   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+   *   The entity type manager.
+   */
+  public function __construct(
+    EntityFieldManager $entity_field_manager,
+    RouteMatchInterface $route_match,
+    EntityTypeManagerInterface $entity_type_manager) {
+    $this->mediaBundleStorage = $entity_type_manager->getStorage('media_bundle');
+    parent::__construct($entity_field_manager, $route_match);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function onResponse(FilterResponseEvent $event) {
+    $response = $event->getResponse();
+
+    $entity = $this->getObject($response, 'media');
+
+    if ($entity === FALSE) {
+      return;
+    }
+
+    $media_bundle = $this->mediaBundleStorage->load($entity->bundle());
+
+    $type_configuration = $media_bundle->getTypeConfiguration();
+
+    if (!isset($type_configuration['source_field'])) {
+      return;
+    }
+    $source_field = $type_configuration['source_field'];
+
+    if (empty($source_field) ||
+      !$entity instanceof FieldableEntityInterface ||
+      !$entity->hasField($source_field)
+    ) {
+      return;
+    }
+
+    // Collect file links for the media.
+    $links = [];
+    foreach ($entity->get($source_field)->referencedEntities() as $referencedEntity) {
+      if ($entity->access('view')) {
+        $file_url = $referencedEntity->url('canonical', ['absolute' => TRUE]);
+        $edit_media_url = Url::fromRoute('islandora.media_source_update', ['media' => $referencedEntity->id()])
+          ->setAbsolute()
+          ->toString();
+        $links[] = "<$file_url>; rel=\"describes\"; type=\"{$referencedEntity->getMimeType()}\"";
+        $links[] = "<$edit_media_url>; rel=\"edit-media\"";
+      }
+    }
+
+    // Exit early if there aren't any.
+    if (empty($links)) {
+      return;
+    }
+
+    // Add the link headers to the response.
+    $response->headers->set('Link', $links, FALSE);
+
+  }
+
+}

src/EventSubscriber/NodeLinkHeaderSubscriber.php

@@ -2,58 +2,15 @@
 
 namespace Drupal\islandora\EventSubscriber;
 
-use Drupal\Core\Entity\EntityFieldManager;
-use Drupal\Core\Routing\RouteMatchInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpKernel\Event\FilterResponseEvent;
-use Symfony\Component\HttpKernel\KernelEvents;
 
 /**
  * Class NodeLinkHeaderSubscriber.
  *
  * @package Drupal\islandora\EventSubscriber
  */
-class NodeLinkHeaderSubscriber implements EventSubscriberInterface {
-
-  /**
-   * The entity field manager.
-   *
-   * @var \Drupal\Core\Entity\EntityFieldManager
-   */
-  protected $entityFieldManager;
-
-  /**
-   * The route match object.
-   *
-   * @var \Drupal\Core\Routing\RouteMatchInterface
-   */
-  protected $routeMatch;
-
-  /**
-   * Constructor.
-   *
-   * @param \Drupal\Core\Entity\EntityFieldManager $entity_field_manager
-   *   The entity field manager.
-   * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
-   *   The route match object.
-   */
-  public function __construct(
-    EntityFieldManager $entity_field_manager,
-    RouteMatchInterface $route_match
-  ) {
-    $this->entityFieldManager = $entity_field_manager;
-    $this->routeMatch = $route_match;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function getSubscribedEvents() {
-    // Run this early so the headers get cached.
-    $events[KernelEvents::RESPONSE][] = ['onResponse', 129];
-
-    return $events;
-  }
+class NodeLinkHeaderSubscriber extends LinkHeaderSubscriber implements EventSubscriberInterface {
 
   /**
    * Adds node-specific link headers to appropriate responses.
@@ -64,44 +21,14 @@ class NodeLinkHeaderSubscriber implements EventSubscriberInterface {
   public function onResponse(FilterResponseEvent $event) {
     $response = $event->getResponse();
 
-    // Exit early if the response is already cached.
-    if ($response->headers->get('X-Drupal-Dynamic-Cache') == 'HIT') {
-      return;
-    }
-
-    if (!$response->isOk()) {
-      return;
-    }
-
-    // Hack the node out of the route.
-    $route_object = $this->routeMatch->getRouteObject();
-    if (!$route_object) {
-      return;
-    }
-
-    $methods = $route_object->getMethods();
-    $is_get = in_array('GET', $methods);
-    $is_head = in_array('HEAD', $methods);
-    if (!($is_get || $is_head)) {
-      return;
-    }
-
-    $route_contexts = $route_object->getOption('parameters');
-    if (!$route_contexts) {
-      return;
-    }
-    if (!isset($route_contexts['node'])) {
-      return;
-    }
-
-    $node = $this->routeMatch->getParameter('node');
+    $entity = $this->getObject($response, 'node');
 
-    if (!$node) {
+    if ($entity === FALSE) {
       return;
     }
 
     // Use the node to add link headers for each entity reference.
-    $bundle = $node->bundle();
+    $bundle = $entity->bundle();
 
     // Get all fields for the entity.
     $fields = $this->entityFieldManager->getFieldDefinitions('node', $bundle);
@@ -114,7 +41,7 @@ class NodeLinkHeaderSubscriber implements EventSubscriberInterface {
     // Collect links for referenced entities.
     $links = [];
     foreach ($entity_reference_fields as $field_name => $field_definition) {
-      foreach ($node->get($field_name)->referencedEntities() as $referencedEntity) {
+      foreach ($entity->get($field_name)->referencedEntities() as $referencedEntity) {
         // Headers are subject to an access check.
         if ($referencedEntity->access('view')) {
           $entity_url = $referencedEntity->url('canonical', ['absolute' => TRUE]);

tests/src/Functional/IslandoraFunctionalTestBase.php

@@ -3,6 +3,7 @@
 namespace Drupal\Tests\islandora\Functional;
 
 use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Url;
 use Drupal\Tests\BrowserTestBase;
 use Drupal\Tests\TestFileCreationTrait;
 
@@ -56,6 +57,7 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
     ]);
     $hello_world->save();
 
+    $this->container->get('router.builder')->rebuild();
   }
 
   /**
@@ -94,7 +96,7 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
     $file = current($this->getTestFiles('image'));
     $values = [
       'name[0][value]' => 'Test Media',
-      'files[field_image_0]' => drupal_realpath($file->uri),
+      'files[field_image_0]' => \Drupal::service('file_system')->realpath($file->uri),
     ];
     $this->drupalPostForm('media/add/tn', $values, t('Save and publish'));
     $values = [
@@ -102,8 +104,20 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
     ];
     $this->getSession()->getPage()->fillField('edit-field-image-0-alt', 'alt text');
     $this->getSession()->getPage()->pressButton(t('Save and publish'));
-    $this->assertResponse(200);
-    return $this->getUrl();
+    $this->assertSession()->statusCodeEquals(200);
+    $results = $this->container->get('entity_type.manager')->getStorage('file')->loadByProperties(['filename' => $file->filename]);
+    $file_entity = reset($results);
+    $file_url = $file_entity->url('canonical', ['absolute' => TRUE]);
+    $rest_url = Url::fromRoute('islandora.media_source_update', ['media' => $file_entity->id()])
+      ->setAbsolute()
+      ->toString();
+    return [
+      'media' => $this->getUrl(),
+      'file' => [
+        'file' => $file_url,
+        'rest' => $rest_url,
+      ],
+    ];
   }
 
   /**
@@ -111,7 +125,7 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
    */
   protected function postNodeAddForm($bundle_id, $values, $button_text) {
     $this->drupalPostForm("node/add/$bundle_id", $values, t('@text', ['@text' => $button_text]));
-    $this->assertResponse(200);
+    $this->assertSession()->statusCodeEquals(200);
   }
 
   /**
@@ -119,7 +133,7 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
    */
   protected function postEntityEditForm($entity_url, $values, $button_text) {
     $this->drupalPostForm("$entity_url/edit", $values, t('@text', ['@text' => $button_text]));
-    $this->assertResponse(200);
+    $this->assertSession()->statusCodeEquals(200);
   }
 
   /**
@@ -144,7 +158,7 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
   }
 
   /**
-   * Checks if the collection link header contains the correct uri.
+   * Checks if the correct link header exists for an Entity.
    *
    * @param string $rel
    *   The expected relation type of the link header.
@@ -152,17 +166,42 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
    *   The entity whose uri is expected in the link header.
    * @param string $title
    *   The expected title of the link header.
+   * @param string $type
+   *   The expected mimetype for the link header.
+   *
+   * @return int
+   *   The number of times the correct header appears.
+   */
+  protected function validateLinkHeaderWithEntity($rel, EntityInterface $entity, $title = '', $type = '') {
+    $entity_url = $entity->toUrl('canonical', ['absolute' => TRUE])
+      ->toString();
+    return $this->validateLinkHeaderWithUrl($rel, $entity_url, $title, $type);
+  }
+
+  /**
+   * Checks if the correct link header exists for a string URI.
+   *
+   * @param string $rel
+   *   The expected relation type of the link header.
+   * @param string $url
+   *   The uri is expected in the link header.
+   * @param string $title
+   *   The expected title of the link header.
+   * @param string $type
+   *   The expected mimetype for the link header.
    *
    * @return int
    *   The number of times the correct header appears.
    */
-  protected function validateLinkHeader($rel, EntityInterface $entity, $title = '') {
-    $entity_url = $entity->url('canonical', ['absolute' => TRUE]);
+  protected function validateLinkHeaderWithUrl($rel, $url, $title = '', $type = '') {
 
     $regex = '/<(.*)>; rel="' . preg_quote($rel) . '"';
     if (!empty($title)) {
       $regex .= '; title="' . preg_quote($title) . '"';
     }
+    if (!empty($type)) {
+      $regex .= '; type="' . preg_quote($type, '/') . '"';
+    }
     $regex .= '/';
 
     $count = 0;
@@ -173,7 +212,7 @@ class IslandoraFunctionalTestBase extends BrowserTestBase {
       $split = explode(',', $link_headers);
       foreach ($split as $link_header) {
         $matches = [];
-        if (preg_match($regex, $link_header, $matches) && $matches[1] == $entity_url) {
+        if (preg_match($regex, $link_header, $matches) && $matches[1] == $url) {
           $count++;
         }
       }

tests/src/Functional/MediaLinkHeaderTest.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace Drupal\Tests\islandora\Functional;
+
+/**
+ * Tests the MediaLinkHeader event subscriber.
+ *
+ * @group islandora
+ */
+class MediaLinkHeaderTest extends IslandoraFunctionalTestBase {
+
+  /**
+   * @covers \Drupal\islandora\EventSubscriber\MediaLinkHeaderSubscriber
+   */
+  public function testMediaLinkHeaders() {
+    // Create a test user.
+    $account = $this->drupalCreateUser([
+      'view media',
+      'create media',
+      'update media',
+    ]);
+    $this->drupalLogin($account);
+
+    $urls = $this->createThumbnailWithFile();
+
+    $this->drupalGet($urls['media'], [], ['Cache-Control: no-cache']);
+
+    $this->assertTrue(
+      $this->validateLinkHeaderWithUrl('describes', $urls['file']['file'], '', 'image/png') == 1,
+      "Malformed 'describes' link header"
+    );
+    $this->assertTrue(
+      $this->validateLinkHeaderWithUrl('edit-media', $urls['file']['rest'], '', '') == 1,
+      "Malformed 'edit-media' link header"
+    );
+  }
+
+}

tests/src/Functional/MediaSourceUpdateTest.php

@@ -44,7 +44,8 @@ class MediaSourceUpdateTest extends IslandoraFunctionalTestBase {
     $this->drupalLogin($account);
 
     // Make a media and give it a png.
-    $url = $this->createThumbnailWithFile();
+    $urls = $this->createThumbnailWithFile();
+    $url = $urls['media'];
 
     // Hack out the guzzle client.
     $client = $this->getSession()->getDriver()->getClient()->getClient();

tests/src/Functional/RelatedLinkHeaderTest.php

@@ -119,11 +119,11 @@ class RelatedLinkHeaderTest extends IslandoraFunctionalTestBase {
     // for both the referenced node and media entity.
     $this->drupalGet('node/' . $this->referencer->id());
     $this->assertTrue(
-      $this->validateLinkHeader('related', $this->referenced, 'Referenced Entity') == 1,
+      $this->validateLinkHeaderWithEntity('related', $this->referenced, 'Referenced Entity') == 1,
       "Malformed related link header"
     );
     $this->assertTrue(
-      $this->validateLinkHeader('related', $this->media, 'Media Entity') == 1,
+      $this->validateLinkHeaderWithEntity('related', $this->media, 'Media Entity') == 1,
       "Malformed related link header"
     );
 
@@ -135,11 +135,11 @@ class RelatedLinkHeaderTest extends IslandoraFunctionalTestBase {
     // for both the referenced node and media entity.
     $this->drupalGet('node/' . $this->referencer->id());
     $this->assertTrue(
-      $this->validateLinkHeader('related', $this->referenced, 'Referenced Entity') == 1,
+      $this->validateLinkHeaderWithEntity('related', $this->referenced, 'Referenced Entity') == 1,
       "Malformed related link header"
     );
     $this->assertTrue(
-      $this->validateLinkHeader('related', $this->media, 'Media Entity') == 0,
+      $this->validateLinkHeaderWithEntity('related', $this->media, 'Media Entity') == 0,
       "Anonymous should not be able to see media link header"
     );
   }