1 files changed, 57 insertions, 0 deletions
diff --git a/core/modules/contextual/src/Hook/ContextualThemeHooks.php b/core/modules/contextual/src/Hook/ContextualThemeHooks.php
new file mode 100644
index 00000000000..47db1f9bde6
--- /dev/null
+++ b/core/modules/contextual/src/Hook/ContextualThemeHooks.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace Drupal\contextual\Hook;
+
+use Drupal\Core\Hook\Attribute\Preprocess;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Hook implementations for contextual.
+ */
+class ContextualThemeHooks {
+
+  public function __construct(
+    protected readonly AccountInterface $currentUser,
+  ) {}
+
+  /**
+   * Implements hook_preprocess().
+   *
+   * @see \Drupal\contextual\Element\ContextualLinksPlaceholder
+   * @see contextual_page_attachments()
+   * @see \Drupal\contextual\ContextualController::render()
+   */
+  #[Preprocess]
+  public function preprocess(&$variables, $hook, $info): void {
+    // Determine the primary theme function argument.
+    if (!empty($info['variables'])) {
+      $keys = array_keys($info['variables']);
+      $key = $keys[0];
+    }
+    elseif (!empty($info['render element'])) {
+      $key = $info['render element'];
+    }
+    if (!empty($key) && isset($variables[$key])) {
+      $element = $variables[$key];
+    }
+
+    if (isset($element) && is_array($element) && !empty($element['#contextual_links'])) {
+      $variables['#cache']['contexts'][] = 'user.permissions';
+      if ($this->currentUser->hasPermission('access contextual links')) {
+        // Mark this element as potentially having contextual links attached to it.
+        $variables['attributes']['class'][] = 'contextual-region';
+
+        // Renders a contextual links placeholder unconditionally, thus not breaking
+        // the render cache. Although the empty placeholder is rendered for all
+        // users, contextual_page_attachments() only adds the asset library for
+        // users with the 'access contextual links' permission, thus preventing
+        // unnecessary HTTP requests for users without that permission.
+        $variables['title_suffix']['contextual_links'] = [
+          '#type' => 'contextual_links_placeholder',
+          '#id' => _contextual_links_to_id($element['#contextual_links']),
+        ];
+      }
+    }
+  }
+
+}