Detect access before showing manage links.

src/Controller/ManageMediaController.php

@@ -6,6 +6,7 @@ use Drupal\islandora\IslandoraUtils;
 use Drupal\Core\Access\AccessResult;
 use Drupal\Core\Routing\RouteMatch;
 use Drupal\node\Entity\Node;
+use Drupal\Core\Url;
 use Drupal\node\NodeInterface;
 
 /**
@@ -34,13 +35,18 @@ class ManageMediaController extends ManageMembersController {
       ['query' => ["edit[$field][widget][0][target_id]" => $node->id()]]
     );
 
+    $manage_link = Url::fromRoute('entity.media_type.collection')->toRenderArray();
+    $manage_link['#title'] = $this->t('Manage media types');
+    $manage_link['#type'] = 'link';
+    $manage_link['#prefix'] = ' ';
+    $manage_link['#suffix'] = '.';
+
     return [
       '#type' => 'markup',
-      '#markup' => $this->t("The following media types can be added because they have the <code>@field</code> field. <a href=@manage_media_page>Manage media types</a>.",
-        [
-          '@field' => $field,
-          '@manage_media_page' => '/admin/structure/media',
-        ]),
+      '#markup' => $this->t("The following media types can be added because they have the <code>@field</code> field.", [
+        '@field' => $field,
+      ]),
+      'manage_link' => $manage_link,
       'add_media' => $add_media_list,
     ];
   }

src/Controller/ManageMembersController.php

@@ -7,6 +7,7 @@ use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\Entity\Controller\EntityController;
 use Drupal\Core\Entity\EntityFieldManagerInterface;
 use Drupal\Core\Link;
+use Drupal\Core\Url;
 use Drupal\islandora\IslandoraUtils;
 use Drupal\node\NodeInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
@@ -98,13 +99,18 @@ class ManageMembersController extends EntityController {
       ['query' => ["edit[$field][widget][0][target_id]" => $node->id()]]
     );
 
+    $manage_link = Url::fromRoute('entity.node_type.collection')->toRenderArray();
+    $manage_link['#title'] = $this->t('Manage content types');
+    $manage_link['#type'] = 'link';
+    $manage_link['#prefix'] = ' ';
+    $manage_link['#suffix'] = '.';
+
     return [
       '#type' => 'markup',
-      '#markup' => $this->t("The following content types can be added because they have the <code>@field</code> field. <a href=@manage_content_types>Manage content types</a>.",
-        [
-          '@field' => $field,
-          '@manage_content_types' => '/admin/structure/types',
-        ]),
+      '#markup' => $this->t("The following content types can be added because they have the <code>@field</code> field.", [
+        '@field' => $field,
+      ]),
+      'manage_link' => $manage_link,
       'add_node' => $add_node_list,
     ];
   }