Added PreviewLinkAutopopulate plugin to auto-populate preview links

src/Plugin/Block/SubsitesHierarchyTrait.php

@@ -123,4 +123,41 @@ protected function getRootId(EntityInterface $entity): ?int {
     return NULL;
   }
 
+  /**
+   * Get flattened list of nodes in subsite hierarchy.
+   *
+   * This does not do any access checks so unpublished nodes may be returned. If
+   * this becomes a requirement then it should be extended to include this.
+   *
+   * @param \Drupal\node\NodeInterface $node
+   *   Any entity in the hierarchy.
+   *
+   * @return array
+   *   Flattened list of nodes in subsite hierarchy.
+   */
+  public function getFlattenedSubsiteHierarchy(NodeInterface $node): array {
+    $nodes = [];
+
+    $storage = $this->getNestedSetStorage('localgov_subsites');
+    $node_key = $this->getNestedSetNodeKeyFactory()->fromEntity($node);
+    if ($ancestors = $storage->findAncestors($node_key)) {
+      $tree = $storage->findDescendants($ancestors[0]->getNodeKey());
+      array_unshift($tree, $ancestors[0]);
+      $mapper = \Drupal::service('entity_hierarchy.entity_tree_node_mapper');
+      $ancestor_entities = $mapper->loadEntitiesForTreeNodesWithoutAccessChecks('node', $tree);
+      foreach ($ancestor_entities as $ancestor_entity) {
+        if (!$ancestor_entities->contains($ancestor_entity)) {
+          // Doesn't exist or is access hidden.
+          continue;
+        }
+        $entity = $ancestor_entities->offsetGet($ancestor_entity);
+        if ($entity instanceof NodeInterface) {
+          $nodes[] = $entity;
+        }
+      }
+    }
+
+    return $nodes;
+  }
+
 }

src/Plugin/PreviewLinkAutopopulate/Subsites.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace Drupal\localgov_subsites\Plugin\PreviewLinkAutopopulate;
+
+use Drupal\localgov_subsites\Plugin\Block\SubsitesHierarchyTrait;
+use Drupal\preview_link\PreviewLinkAutopopulatePluginBase;
+
+/**
+ * Auto-populate subsite preview links.
+ *
+ * @PreviewLinkAutopopulate(
+ *   id = "localgov_subsites",
+ *   label = @Translation("Add all the pages for this subsite"),
+ *   description = @Translation("Add subsite overview and page nodes to preview link."),
+ *   supported_entities = {
+ *     "node" = {
+ *       "localgov_subsites_overview",
+ *       "localgov_subsites_page",
+ *     }
+ *   },
+ * )
+ */
+class Subsites extends PreviewLinkAutopopulatePluginBase {
+
+  use SubsitesHierarchyTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getPreviewEntities(): array {
+    return $this->getFlattenedSubsiteHierarchy($this->entity);
+  }
+
+}

tests/src/Kernel/SubsitesHierarchyTraitTest.php

@@ -0,0 +1,138 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\localgov_subsites\Kernel;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\localgov_subsites\Plugin\Block\SubsitesHierarchyTrait;
+use Drupal\node\NodeInterface;
+use Drupal\Tests\node\Traits\ContentTypeCreationTrait;
+use Drupal\Tests\node\Traits\NodeCreationTrait;
+
+/**
+ * Test SubsitesHierarchyTrait methods.
+ *
+ * @group localgov_subsites
+ */
+class SubsitesHierarchyTraitTest extends KernelTestBase {
+
+  use ContentTypeCreationTrait;
+  use NodeCreationTrait;
+  use SubsitesHierarchyTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'dbal',
+    'field',
+    'filter',
+    'entity_hierarchy',
+    'language',
+    'link',
+    'node',
+    'path',
+    'system',
+    'text',
+    'token',
+    'user',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installEntitySchema('user');
+    $this->installEntitySchema('node');
+    $this->installSchema('node', ['node_access']);
+    $this->installConfig([
+      'filter',
+      'system',
+      'user',
+      'node',
+    ]);
+
+    // Create subsite content types and entity hierarchy field.
+    $this->createContentType([
+      'type' => 'localgov_subsites_overview',
+      'name' => 'Subsites Overview',
+    ]);
+    $this->createContentType([
+      'type' => 'localgov_subsites_page',
+      'name' => 'Subsites Page',
+    ]);
+    $storage = FieldStorageConfig::create([
+      'entity_type' => 'node',
+      'field_name' => 'localgov_subsites_parent',
+      'id' => 'node.localgov_subsites_parent',
+      'type' => 'entity_reference_hierarchy',
+      'settings' => [
+        'target_type' => 'node',
+      ],
+    ]);
+    $storage->save();
+    $config = FieldConfig::create([
+      'field_name' => 'localgov_subsites_parent',
+      'entity_type' => 'node',
+      'bundle' => 'localgov_subsites_page',
+      'id' => 'node.localgov_subsites_page.localgov_subsites_parent',
+      'label' => 'Parent',
+    ]);
+    $config->save();
+  }
+
+  /**
+   * Test callback.
+   */
+  public function testGetFlattenedSubsiteHierarchy(): void {
+
+    // Create subsite hierarchy.
+    $subsite_overview = $this->createNode([
+      'title' => $this->randomString(),
+      'type' => 'localgov_subsites_overview',
+      'status' => NodeInterface::PUBLISHED,
+    ]);
+    $subsite_overview->save();
+    $subsite_page1 = $this->createNode([
+      'title' => $this->randomString(),
+      'type' => 'localgov_subsites_page',
+      'localgov_subsites_parent' => [
+        'target_id' => $subsite_overview->id(),
+        'weight' => 0,
+      ],
+      'status' => NodeInterface::NOT_PUBLISHED,
+    ]);
+    $subsite_page1->save();
+    $subsite_page2 = $this->createNode([
+      'title' => $this->randomString(),
+      'type' => 'localgov_subsites_page',
+      'localgov_subsites_parent' => [
+        'target_id' => $subsite_overview->id(),
+        'weight' => 0,
+      ],
+      'status' => NodeInterface::PUBLISHED,
+    ]);
+    $subsite_page2->save();
+    $subsite_page3 = $this->createNode([
+      'title' => $this->randomString(),
+      'type' => 'localgov_subsites_page',
+      'localgov_subsites_parent' => [
+        'target_id' => $subsite_page2->id(),
+        'weight' => 0,
+      ],
+      'status' => NodeInterface::PUBLISHED,
+    ]);
+    $subsite_page3->save();
+
+    $this->assertCount(4, $this->getFlattenedSubsiteHierarchy($subsite_overview));
+    $this->assertCount(4, $this->getFlattenedSubsiteHierarchy($subsite_page1));
+    $this->assertCount(4, $this->getFlattenedSubsiteHierarchy($subsite_page2));
+    $this->assertCount(4, $this->getFlattenedSubsiteHierarchy($subsite_page3));
+  }
+
+}