Issue #3443833 by plopesc, m4olivei, gábor hojtsy, matthieuscarset,...

Issue #3443833 by plopesc, m4olivei, gábor hojtsy, matthieuscarset, penyaskito, larowlan, tim.plunkett: Provide a way for other modules to flag block plugin implementations as 'navigation safe'

core/modules/navigation/src/Hook/NavigationHooks.php

@@ -131,12 +131,10 @@ public function blockBuildLocalTasksBlockAlter(array &$build, BlockPluginInterfa
   #[Hook('plugin_filter_block__layout_builder_alter')]
   public function pluginFilterBlockLayoutBuilderAlter(array &$definitions, array $extra): void {
     if (($extra['section_storage'] ?? NULL) instanceof NavigationSectionStorage) {
-      // Remove all blocks other than the ones we support.
-      $navigation_safe = ['navigation_user', 'navigation_shortcuts', 'navigation_menu'];
-      $definitions = array_filter($definitions, static function (array $definition, string $plugin_id) use ($navigation_safe) : bool {
-          [$base_plugin_id] = explode(PluginBase::DERIVATIVE_SEPARATOR, $plugin_id);
-          return in_array($base_plugin_id, $navigation_safe, TRUE);
-      }, ARRAY_FILTER_USE_BOTH);
+      // Include only blocks explicitly indicated as Navigation allowed.
+      $definitions = array_filter($definitions,
+        fn (array $definition): bool => ($definition['allow_in_navigation'] ?? FALSE) === TRUE
+      );
     }
   }
 
@@ -156,12 +154,28 @@ public function pluginFilterLayoutLayoutBuilderAlter(array &$definitions, array
    */
   #[Hook('block_alter')]
   public function blockAlter(&$definitions) : void {
+    // Hide Navigation specific blocks from the generic UI.
     $hidden = ['navigation_user', 'navigation_shortcuts', 'navigation_menu', 'navigation_link'];
     foreach ($hidden as $block_id) {
       if (isset($definitions[$block_id])) {
         $definitions[$block_id]['_block_ui_hidden'] = TRUE;
       }
     }
+
+    // Add the allow_in_navigation attribute to those blocks valid for Navigation.
+    // @todo Refactor to use actual block Attribute once
+    //   https://www.drupal.org/project/drupal/issues/3443882 is merged.
+    array_walk($definitions, function (&$definition, $block_id) {
+      $allow_in_navigation = [
+        'navigation_user',
+        'navigation_shortcuts',
+        'navigation_menu',
+      ];
+      [$base_plugin_id] = explode(PluginBase::DERIVATIVE_SEPARATOR, $block_id);
+      if (in_array($base_plugin_id, $allow_in_navigation, TRUE)) {
+        $definition['allow_in_navigation'] = TRUE;
+      }
+    });
   }
 
   /**

core/modules/navigation/tests/navigation_test/src/Hook/NavigationTestHooks.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\navigation_test\Hook;
+
+use Drupal\Core\Hook\Attribute\Hook;
+use Drupal\Core\State\StateInterface;
+
+/**
+ * Hooks implementations for navigation_test module.
+ */
+class NavigationTestHooks {
+
+  /**
+   * NavigationTestHooks constructor.
+   *
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state service.
+   */
+  public function __construct(
+    protected StateInterface $state,
+  ) {
+  }
+
+  /**
+   * Implements hook_block_alter().
+   */
+  #[Hook('block_alter')]
+  public function blockAlter(&$definitions): void {
+    if ($this->state->get('navigation_safe_alter')) {
+      $definitions['navigation_link']['allow_in_navigation'] = TRUE;
+      $definitions['navigation_shortcuts']['allow_in_navigation'] = FALSE;
+    }
+  }
+
+}

core/modules/navigation/tests/src/Functional/NavigationSafeBlockDefinitionTest.php

+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\navigation\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests the definition of navigation safe blocks.
+ *
+ * @group navigation
+ */
+class NavigationSafeBlockDefinitionTest extends BrowserTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = ['navigation', 'navigation_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * User with permission to administer navigation blocks and access navigation.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $adminUser;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    // Create an admin user, log in and enable test navigation blocks.
+    $this->adminUser = $this->drupalCreateUser([
+      'configure navigation layout',
+      'access navigation',
+    ]);
+
+    $this->drupalLogin($this->adminUser);
+  }
+
+  /**
+   * Tests logic to include blocks in Navigation Layout UI.
+   */
+  public function testNavigationSafeBlockDefinition(): void {
+    // Confirm that default blocks are available.
+    $layout_url = '/admin/config/user-interface/navigation-block';
+    $this->drupalGet($layout_url);
+    $this->clickLink('Add block');
+
+    $this->assertSession()->linkExists('Administration');
+    $this->assertSession()->linkExists('Content');
+    $this->assertSession()->linkExists('Footer');
+    $this->assertSession()->linkExists('Navigation Shortcuts');
+    $this->assertSession()->linkExists('User');
+    $this->assertSession()->linkNotExists('Link');
+
+    // Apply changes, clear cache and confirm that changes are applied.
+    \Drupal::state()->set('navigation_safe_alter', TRUE);
+    \Drupal::cache('discovery')->delete('block_plugins');
+
+    $this->drupalGet($this->getUrl());
+    $this->assertSession()->linkExists('Administration');
+    $this->assertSession()->linkExists('Content');
+    $this->assertSession()->linkExists('Footer');
+    $this->assertSession()->linkExists('Link');
+    $this->assertSession()->linkNotExists('Navigation Shortcuts');
+  }
+
+}