header link settings

config/install/islandora.settings.yml

@@ -2,3 +2,4 @@ broker_url: 'tcp://localhost:61613'
 jwt_expiry: '+2 hour'
 delete_media_and_files: TRUE
 gemini_pseudo_bundles: []
+allow_header_links: TRUE

config/schema/islandora.schema.yml

@@ -14,6 +14,9 @@ islandora.settings:
     jwt_expiry:
       type: string
       label: 'How long JWTs should last before expiring.'
+    allow_header_links:
+      type: boolean
+      label: 'Allow generating links in the HTTP header'
     delete_media_and_files:
       type: boolean
       label: 'Node Delete with Media and Files'

src/EventSubscriber/LinkHeaderSubscriber.php

@@ -2,6 +2,7 @@
 
 namespace Drupal\islandora\EventSubscriber;
 
+use Drupal\Core\Config\ConfigFactoryInterface;
 use Symfony\Component\HttpKernel\Event\ResponseEvent;
 use Drupal\Core\Access\AccessManagerInterface;
 use Drupal\Core\Entity\EntityFieldManagerInterface;
@@ -72,6 +73,13 @@ abstract class LinkHeaderSubscriber implements EventSubscriberInterface {
    */
   protected $utils;
 
+  /**
+   * Module settings.
+   *
+   * @var \Drupal\Core\Config\ImmutableConfig
+   */
+  protected $settings;
+
   /**
    * Constructor.
    *
@@ -89,6 +97,8 @@ abstract class LinkHeaderSubscriber implements EventSubscriberInterface {
    *   Request stack (for current request).
    * @param \Drupal\islandora\IslandoraUtils $utils
    *   Islandora utils.
+   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
+   *   Config factory.
    */
   public function __construct(
     EntityTypeManagerInterface $entity_type_manager,
@@ -97,7 +107,8 @@ public function __construct(
     AccountInterface $account,
     RouteMatchInterface $route_match,
     RequestStack $request_stack,
-    IslandoraUtils $utils
+    IslandoraUtils $utils,
+    ConfigFactoryInterface $config_factory
   ) {
     $this->entityTypeManager = $entity_type_manager;
     $this->entityFieldManager = $entity_field_manager;
@@ -108,6 +119,7 @@ public function __construct(
     $this->account = $account;
     $this->requestStack = $request_stack;
     $this->utils = $utils;
+    $this->settings = $config_factory->get('islandora.settings');
   }
 
   /**

src/EventSubscriber/MediaLinkHeaderSubscriber.php

@@ -18,6 +18,9 @@ class MediaLinkHeaderSubscriber extends LinkHeaderSubscriber implements EventSub
    * {@inheritdoc}
    */
   public function onResponse(ResponseEvent $event) {
+    if (!$this->settings->get('allow_header_links')) {
+      return;
+    }
     $response = $event->getResponse();
 
     $media = $this->getObject($response, 'media');

src/EventSubscriber/NodeLinkHeaderSubscriber.php

@@ -21,6 +21,9 @@ class NodeLinkHeaderSubscriber extends LinkHeaderSubscriber implements EventSubs
    *   Event containing the response.
    */
   public function onResponse(ResponseEvent $event) {
+    if (!$this->settings->get('allow_header_links')) {
+      return;
+    }
     $response = $event->getResponse();
 
     $node = $this->getObject($response, 'node');

src/Form/IslandoraSettingsForm.php

@@ -44,6 +44,7 @@ class IslandoraSettingsForm extends ConfigFormBase {
   const GEMINI_PSEUDO_FIELD = 'field_gemini_uri';
   const NODE_DELETE_MEDIA_AND_FILES = 'delete_media_and_files';
   const REDIRECT_AFTER_MEDIA_SAVE = 'redirect_after_media_save';
+  const ALLOW_HEADER_LINKS = 'allow_header_links';
 
   /**
    * To list the available bundle types.
@@ -271,6 +272,13 @@ public function buildForm(array $form, FormStateInterface $form_state) {
       '#url' => Url::fromRoute('system.jsonld_settings'),
     ];
 
+    $form[self::ALLOW_HEADER_LINKS] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Allow header links'),
+      '#description' => $this->t('If checked, links in the HTTP header will be added'),
+      '#default_value' => (bool) $config->get(self::ALLOW_HEADER_LINKS),
+    ];
+
     return parent::buildForm($form, $form_state);
   }
 
@@ -384,6 +392,7 @@ public function submitForm(array &$form, FormStateInterface $form_state) {
       ->set(self::GEMINI_PSEUDO, $new_pseudo_types)
       ->set(self::NODE_DELETE_MEDIA_AND_FILES, $form_state->getValue(self::NODE_DELETE_MEDIA_AND_FILES))
       ->set(self::REDIRECT_AFTER_MEDIA_SAVE, $form_state->getValue(self::REDIRECT_AFTER_MEDIA_SAVE))
+      ->set(self::ALLOW_HEADER_LINKS, $form_state->getValue(self::ALLOW_HEADER_LINKS))
       ->save();
 
     parent::submitForm($form, $form_state);