Refactor graph loader for readability.

rdf_entity.links.task.yml

@@ -25,3 +25,9 @@ entity.rdf_entity.collection:
   title: RDF
   route_name: entity.rdf_entity.collection
   base_route: system.admin_content
+
+entity.rdf_entity.version_history:
+  route_name: entity.rdf_entity.version_history
+  base_route: entity.rdf_entity.canonical
+  title: 'Revisions'
+  weight: 20

rdf_entity.routing.yml

@@ -11,6 +11,18 @@ entity.rdf_entity.canonical:
   # Calls the access controller of the entity, $operation 'view'.
     _entity_access: 'rdf_entity.view'
 
+entity.rdf_entity.version_history:
+  path: '/rdf_entity/{rdf_entity}/revisions'
+  defaults:
+    _title: 'Revisions'
+    _controller: '\Drupal\rdf_entity\Controller\RdfController::revisionOverview'
+  requirements:
+    _entity_access: 'rdf_entity.edit'
+  options:
+    parameters:
+      rdf_entity:
+        type: entity:rdf_entity
+
 entity.rdf_entity.collection:
   path: 'admin/content/rdf'
   defaults:
@@ -148,3 +160,54 @@ entity.rdf_entity_graph.disable:
     toggle_operation: disable
   requirements:
     _custom_access: 'Drupal\rdf_entity\Controller\RdfEntityGraphToggle::access'
+
+entity.rdf_entity.revision:
+  path: '/rdf_entity/{rdf_entity}/revisions/{rdf_revision}/view'
+  defaults:
+    _controller: 'Drupal\rdf_entity\Controller\RdfController::revisionShow'
+  options:
+    parameters:
+      rdf_entity:
+        type: entity:rdf_entity
+      rdf_revision:
+        type: entity:rdf_entity
+  requirements:
+    # Calls the access controller of the entity, $operation 'view'.
+    _entity_access: 'rdf_entity.view'
+
+rdf_entity.revision_revert_confirm:
+  path: '/rdf_entity/{rdf_entity}/revisions/{rdf_revision}/revert'
+  defaults:
+    _form: '\Drupal\rdf_entity\Form\RdfRevisionRevertForm'
+    _title: 'Revert to earlier revision'
+  options:
+    parameters:
+      rdf_entity:
+        type: entity:rdf_entity
+      rdf_revision:
+        type: entity:rdf_entity
+  requirements:
+    _entity_access: 'rdf_entity.edit'
+# T
+rdf_entity.revision_revert_translation_confirm:
+  path: '/rdf_entity/{rdf_entity}/revisions/{rdf_revision}/revert/{langcode}'
+  defaults:
+    _form: '\Drupal\rdf_entity\Form\RdfRevisionRevertTranslationForm'
+    _title: 'Revert to earlier revision of a translation'
+  parameters:
+    rdf_entity:
+      type: entity:rdf_entity
+    rdf_revision:
+      type: entity:rdf_entity
+
+rdf_entity.revision_delete_confirm:
+  path: '/rdf_entity/{rdf_entity}/revisions/{rdf_revision}/delete'
+  defaults:
+    _form: '\Drupal\rdf_entity\Form\RdfRevisionDeleteForm'
+    _title: 'Delete earlier revision'
+  options:
+    parameters:
+      rdf_entity:
+       type: entity:rdf_entity
+      rdf_revision:
+       type: entity:rdf_entity

rdf_entity.services.yml

@@ -55,3 +55,6 @@ services:
     arguments: ['@typed_data_manager']
     tags:
       - { name: event_subscriber }
+  rdf_entity.graph_priority.filter:
+    class: Drupal\rdf_entity\LayeredGraphPriorityFilter
+    arguments: ['@entity_type.manager']

src/Controller/RdfController.php

@@ -4,13 +4,57 @@
 
 use Drupal\Component\Utility\Xss;
 use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Datetime\DateFormatterInterface;
+use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
+use Drupal\Core\Entity\Controller\EntityViewController;
+use Drupal\Core\Render\RendererInterface;
+use Drupal\Core\Url;
+use Drupal\rdf_entity\RdfEntitySparqlStorageInterface;
 use Drupal\rdf_entity\RdfEntityTypeInterface;
 use Drupal\rdf_entity\RdfInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Provides route responses for rdf_entity.module.
  */
-class RdfController extends ControllerBase {
+class RdfController extends ControllerBase implements ContainerInjectionInterface {
+
+  /**
+   * The date formatter service.
+   *
+   * @var \Drupal\Core\Datetime\DateFormatterInterface
+   */
+  protected $dateFormatter;
+
+  /**
+   * The renderer service.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
+  /**
+   * Constructs a RdfController object.
+   *
+   * @param \Drupal\Core\Datetime\DateFormatterInterface $date_formatter
+   *   The date formatter service.
+   * @param \Drupal\Core\Render\RendererInterface $renderer
+   *   The renderer service.
+   */
+  public function __construct(DateFormatterInterface $date_formatter, RendererInterface $renderer) {
+    $this->dateFormatter = $date_formatter;
+    $this->renderer = $renderer;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function create(ContainerInterface $container) {
+    return new static(
+      $container->get('date.formatter'),
+      $container->get('renderer')
+    );
+  }
 
   /**
    * Route title callback.
@@ -108,4 +152,183 @@ public function addPage() {
     return $build;
   }
 
+  /**
+   * Generates an overview table of older revisions of a entity.
+   *
+   * @param \Drupal\rdf_entity\RdfInterface $rdf_entity
+   *   A rdf object.
+   *
+   * @return array
+   *   An array as expected by \Drupal\Core\Render\RendererInterface::render().
+   *
+   * @throws \Drupal\Component\Plugin\Exception\InvalidPluginDefinitionException
+   * @throws \Drupal\Component\Plugin\Exception\PluginNotFoundException
+   */
+  public function revisionOverview(RdfInterface $rdf_entity) {
+    $account = $this->currentUser();
+    $langcode = $rdf_entity->language()->getId();
+    $langname = $rdf_entity->language()->getName();
+    $languages = $rdf_entity->getTranslationLanguages();
+    $has_translations = (count($languages) > 1);
+    $rdf_storage = $this->entityManager()->getStorage('rdf_entity');
+    $type = $rdf_entity->getType();
+
+    $build['#title'] = $has_translations ? $this->t('@langname revisions for %title', ['@langname' => $langname, '%title' => $rdf_entity->label()]) : $this->t('Revisions for %title', ['%title' => $rdf_entity->label()]);
+    $header = [$this->t('Revision'), $this->t('Operations')];
+
+    $revert_permission = (($account->hasPermission("revert $type revisions") || $account->hasPermission('revert all revisions') || $account->hasPermission('administer nodes')) && $rdf_entity->access('update'));
+    $delete_permission = (($account->hasPermission("delete $type revisions") || $account->hasPermission('delete all revisions') || $account->hasPermission('administer nodes')) && $rdf_entity->access('delete'));
+
+    $rows = [];
+    $default_revision = $rdf_entity->getRevisionId();
+    $current_revision_displayed = FALSE;
+
+    $revisions = $this->getRevisionIds($rdf_entity, $rdf_storage);
+
+    foreach ($revisions as $vid) {
+      /** @var \Drupal\rdf_entity\RdfInterface $revision */
+      $revision = $rdf_storage->loadRevision($vid);
+      // Only show revisions that are affected by the language that is being
+      // displayed.
+      // @todo && $revision->getTranslation($langcode)->isRevisionTranslationAffected()
+      if ($revision->hasTranslation($langcode) ) {
+        $username = [
+          '#theme' => 'username',
+          '#account' => $revision->getRevisionUser(),
+        ];
+
+        // Use revision link to link to revisions that are not active.
+        $date = $this->dateFormatter->format($revision->getChangedTime(), 'short');
+
+        // We treat also the latest translation-affecting revision as current
+        // revision, if it was the default revision, as its values for the
+        // current language will be the same of the current default revision in
+        // this case.
+        $is_current_revision = $vid == $default_revision || (!$current_revision_displayed && $revision->wasDefaultRevision());
+        if (!$is_current_revision) {
+          $link = $this->l($date, new Url('entity.rdf_entity.revision', ['rdf_entity' => $rdf_entity->id(), 'rdf_revision' => $vid]));
+        }
+        else {
+          $link = $rdf_entity->link($date);
+          $current_revision_displayed = TRUE;
+        }
+
+        $row = [];
+        $column = [
+          'data' => [
+            '#type' => 'inline_template',
+            '#template' => '{% trans %}{{ date }} by {{ username }}{% endtrans %}{% if message %}<p class="revision-log">{{ message }}</p>{% endif %}',
+            '#context' => [
+              'date' => $link,
+              'username' => $this->renderer->renderPlain($username),
+              'message' => ['#markup' => $revision->revision_log->value, '#allowed_tags' => Xss::getHtmlTagList()],
+            ],
+          ],
+        ];
+        // @todo Simplify once https://www.drupal.org/node/2334319 lands.
+        $this->renderer->addCacheableDependency($column['data'], $username);
+        $row[] = $column;
+
+        if ($is_current_revision) {
+          $row[] = [
+            'data' => [
+              '#prefix' => '<em>',
+              '#markup' => $this->t('Current revision'),
+              '#suffix' => '</em>',
+            ],
+          ];
+
+          $rows[] = [
+            'data' => $row,
+            'class' => ['revision-current'],
+          ];
+        }
+        else {
+          $links = [];
+          if ($revert_permission) {
+            $links['revert'] = [
+              'title' => $vid < $rdf_entity->getRevisionId() ? $this->t('Revert') : $this->t('Set as current revision'),
+              'url' => $has_translations ?
+                Url::fromRoute('rdf_entity.revision_revert_translation_confirm', ['rdf_rntity' => $rdf_entity->id(), 'rdf_revision' => $vid, 'langcode' => $langcode]) :
+                Url::fromRoute('rdf_entity.revision_revert_confirm', ['rdf_entity' => $rdf_entity->id(), 'rdf_revision' => $vid]),
+            ];
+          }
+
+          if ($delete_permission) {
+            $links['delete'] = [
+              'title' => $this->t('Delete'),
+              'url' => Url::fromRoute('rdf_entity.revision_delete_confirm', ['rdf_entity' => $rdf_entity->id(), 'rdf_revision' => $vid]),
+            ];
+          }
+
+          $row[] = [
+            'data' => [
+              '#type' => 'operations',
+              '#links' => $links,
+            ],
+          ];
+
+          $rows[] = $row;
+        }
+      }
+    }
+
+    $build['node_revisions_table'] = [
+      '#theme' => 'table',
+      '#rows' => $rows,
+      '#header' => $header,
+      '#attached' => [
+        'library' => ['node/drupal.node.admin'],
+      ],
+      '#attributes' => ['class' => 'node-revision-table'],
+    ];
+
+    $build['pager'] = ['#type' => 'pager'];
+
+    // Bypass cache for development
+    $build['#cache']['max-age'] = 0;
+
+    return $build;
+  }
+
+  /**
+   * Gets a list of rdf revision IDs for a specific entity.
+   *
+   * @param \Drupal\rdf_entity\RdfInterface $rdf_entity
+   *   The rdf entity.
+   * @param \Drupal\rdf_entity\RdfEntitySparqlStorageInterface $rdf_storage
+   *   The rdf storage handler.
+   *
+   * @return int[]
+   *   Node revision IDs (in descending order).
+   */
+  protected function getRevisionIds(RdfInterface $rdf_entity, RdfEntitySparqlStorageInterface $rdf_storage) {
+    $query = $rdf_storage->getQuery()
+      ->allRevisions()
+      //->condition($rdf_entity->getEntityType()->getKey('bundle'), 'event')
+      ->condition($rdf_entity->getEntityType()->getKey('id'), $rdf_entity->id())
+      ->sort($rdf_entity->getEntityType()->getKey('revision'), 'DESC')
+      ->pager(50);
+    $result= $query->execute();
+    return array_keys($result);
+  }
+
+
+  /**
+   * Displays a rdf revision.
+   *
+   * @param \Drupal\rdf_entity\RdfInterface $rdf_revision
+   *   The rdf revision.
+   *
+   * @return array
+   *   An array suitable for \Drupal\Core\Render\RendererInterface::render().
+   */
+  public function revisionShow(RdfInterface $rdf_revision) {
+    $rdf_entity = $this->entityManager()->getTranslationFromContext($rdf_revision);
+    $view_controller = new EntityViewController($this->entityManager, $this->renderer);
+    $page = $view_controller->view($rdf_entity);
+    unset($page['#cache']);
+    return $page;
+  }
+
 }

src/Entity/Query/Sparql/Query.php

@@ -352,6 +352,14 @@ protected function conditionGroupFactory($conjunction = 'AND') {
     return new $class($conjunction, $this, $this->namespaces, $this->graphHandler, $this->fieldHandler);
   }
 
+  public function getLatestRevision() {
+    return $this->latestRevision;
+  }
+
+  public function getAllRevisions() {
+    return $this->allRevisions;
+  }
+
   /**
    * Return the query string for debugging help.
    *

src/Entity/Query/Sparql/SparqlCondition.php

@@ -295,6 +295,16 @@ public function condition($field = NULL, $value = NULL, $operator = NULL, $lang
    *    Thrown if the value is NULL or the operator is not allowed.
    */
   public function keyCondition($field, $value, $operator) {
+    // Revision handling.
+    $query = $this->query;
+    if ($query instanceof SparqlQueryInterface) {
+      if ($field === 'id' && $query->getAllRevisions()) {
+        $field = 'vid';
+      }
+    }
+
+
+
     // @todo: Add support for loadMultiple with empty Id (load all).
     if ($value == NULL) {
       throw new \Exception('The value cannot be NULL for conditions related to the Id and bundle keys.');

src/Entity/Query/Sparql/SparqlQueryInterface.php

@@ -44,4 +44,7 @@ public function getEntityType(): EntityTypeInterface;
    */
   public function getEntityStorage(): RdfEntitySparqlStorageInterface;
 
+  public function getLatestRevision();
+
+  public function getAllRevisions();
 }