';
+ $build['diff']['#attributes']['class'][] = 'diff-responsive-table';
+ }
+ }
+
+ $build['#attached']['library'][] = 'diff/diff.general';
+ return $build;
+ }
+
+ /**
+ * Builds a navigation dropdown button between the layout plugins.
+ *
+ * @param \Drupal\Core\Entity\ContentEntityInterface $entity
+ * The entity to be compared.
+ * @param int $left_revision_id
+ * Revision id of the left revision.
+ * @param int $right_revision_id
+ * Revision id of the right revision.
+ * @param string $active_filter
+ * The active filter.
+ *
+ * @return array
+ * The layout filter.
+ */
+ protected function buildLayoutNavigation(ContentEntityInterface $entity, $left_revision_id, $right_revision_id, $active_filter) {
+ $links = [];
+ $layouts = $this->diffLayoutManager->getPluginOptions();
+ foreach ($layouts as $key => $value) {
+ $links[$key] = array(
+ 'title' => $value,
+ 'url' => $this->diffRoute($entity, $left_revision_id, $right_revision_id, $key),
+ );
+ }
+
+ // Set as the first element the current filter.
+ $filter = $links[$active_filter];
+ unset($links[$active_filter]);
+ array_unshift($links, $filter);
+
+ $filter = [
+ '#type' => 'operations',
+ '#links' => $links,
+ ];
+
+ return $filter;
+ }
+
+ /**
+ * Creates navigation links between the previous changes and the new ones.
+ *
+ * @param \Drupal\Core\Entity\ContentEntityInterface $entity
+ * The entity to be compared.
+ * @param array $revision_ids
+ * The revision ids.
+ * @param int $left_revision_id
+ * Revision id of the left revision.
+ * @param int $right_revision_id
+ * Revision id of the right revision.
+ * @param string $filter
+ * The filter.
+ *
+ * @return array
+ * The revision navigation links.
+ */
+ protected function buildRevisionsNavigation(ContentEntityInterface $entity, array $revision_ids, $left_revision_id, $right_revision_id, $filter) {
+ $revisions_count = count($revision_ids);
+ $layout_options = &drupal_static(__FUNCTION__);
+ if (!isset($layout_options)) {
+ $layout_options = UrlHelper::filterQueryParameters($this->requestStack->getCurrentRequest()->query->all(), ['page']);
+ }
+ // If there are only 2 revision return an empty row.
+ if ($revisions_count == 2) {
+ return [];
+ }
+ else {
+ $left_link = $right_link = '';
+ $element = [
+ '#type' => 'item',
+ '#title' => $this->t('Navigation'),
+ '#wrapper_attributes' => ['class' => 'diff-navigation'],
+ ];
+ $i = 0;
+ // Find the previous revision.
+ while ($left_revision_id > $revision_ids[$i]) {
+ $i += 1;
+ }
+ if ($i != 0) {
+ // Build the left link.
+ $left_link = Link::fromTextAndUrl($this->t('Previous change'), $this->diffRoute($entity, $revision_ids[$i - 1], $left_revision_id, $filter, $layout_options))->toString();
+ }
+ $element['left'] = [
+ '#type' => 'markup',
+ '#markup' => $left_link,
+ '#prefix' => '
',
+ '#suffix' => '
',
+ ];
+ // Find the next revision.
+ $i = 0;
+ while ($i < $revisions_count && $right_revision_id >= $revision_ids[$i]) {
+ $i += 1;
+ }
+ if ($revisions_count != $i && $revision_ids[$i - 1] != $revision_ids[$revisions_count - 1]) {
+ // Build the right link.
+ $right_link = Link::fromTextAndUrl($this->t('Next change'), $this->diffRoute($entity, $right_revision_id, $revision_ids[$i], $filter, $layout_options))->toString();
+ }
+ $element['right'] = [
+ '#type' => 'markup',
+ '#markup' => $right_link,
+ '#prefix' => '
',
+ '#suffix' => '
',
+ ];
+ return $element;
+ }
+ }
+
+ /**
+ * Creates an url object for diff.
+ *
+ * @param \Drupal\Core\Entity\ContentEntityInterface $entity
+ * The entity to be compared.
+ * @param int $left_revision_id
+ * Revision id of the left revision.
+ * @param int $right_revision_id
+ * Revision id of the right revision.
+ * @param string $layout
+ * (optional) The filter/layout added to the route.
+ * @param array $layout_options
+ * (optional) The layout options provided by the selected layout.
+ *
+ * @return \Drupal\Core\Url
+ * The URL object.
+ */
+ public static function diffRoute(ContentEntityInterface $entity, $left_revision_id, $right_revision_id, $layout = NULL, array $layout_options = NULL) {
+ $entity_type_id = $entity->getEntityTypeId();
+ // @todo Remove the diff.revisions_diff route so we avoid adding extra cases.
+ if ($entity->getEntityTypeId() == 'node') {
+ $route_name = 'diff.revisions_diff';
+ }
+ else {
+ $route_name = "entity.$entity_type_id.revisions_diff";
+ }
+ $route_parameters = [
+ $entity_type_id => $entity->id(),
+ 'left_revision' => $left_revision_id,
+ 'right_revision' => $right_revision_id,
+ ];
+ if ($layout) {
+ $route_parameters['filter'] = $layout;
+ }
+ $options = [];
+ if ($layout_options) {
+ $options = [
+ 'query' => $layout_options,
+ ];
+ }
+ return Url::fromRoute($route_name, $route_parameters, $options);
+ }
+
+}