--- /dev/null
+<?php
+
+namespace Drupal\layout_builder\Plugin\Derivative;
+
+use Drupal\Component\Plugin\Derivative\DeriverBase;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
+use Drupal\Core\StringTranslation\StringTranslationTrait;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+ * Provides local task definitions for the layout builder user interface.
+ *
+ * @todo Remove this in https://www.drupal.org/project/drupal/issues/2936655.
+ *
+ * @internal
+ */
+class LayoutBuilderLocalTaskDeriver extends DeriverBase implements ContainerDeriverInterface {
+
+ use StringTranslationTrait;
+
+ /**
+ * The entity type manager.
+ *
+ * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+ */
+ protected $entityTypeManager;
+
+ /**
+ * Constructs a new LayoutBuilderLocalTaskDeriver.
+ *
+ * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
+ * The entity type manager.
+ */
+ public function __construct(EntityTypeManagerInterface $entity_type_manager) {
+ $this->entityTypeManager = $entity_type_manager;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container, $base_plugin_id) {
+ return new static(
+ $container->get('entity_type.manager')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getDerivativeDefinitions($base_plugin_definition) {
+ foreach ($this->getEntityTypesForOverrides() as $entity_type_id => $entity_type) {
+ // Overrides.
+ $this->derivatives["layout_builder.overrides.$entity_type_id.view"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.overrides.$entity_type_id.view",
+ 'weight' => 15,
+ 'title' => $this->t('Layout'),
+ 'base_route' => "entity.$entity_type_id.canonical",
+ 'cache_contexts' => ['layout_builder_is_active:' . $entity_type_id],
+ ];
+ $this->derivatives["layout_builder.overrides.$entity_type_id.save"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.overrides.$entity_type_id.save",
+ 'title' => $this->t('Save Layout'),
+ 'parent_id' => "layout_builder_ui:layout_builder.overrides.$entity_type_id.view",
+ 'cache_contexts' => ['layout_builder_is_active:' . $entity_type_id],
+ ];
+ $this->derivatives["layout_builder.overrides.$entity_type_id.cancel"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.overrides.$entity_type_id.cancel",
+ 'title' => $this->t('Cancel Layout'),
+ 'parent_id' => "layout_builder_ui:layout_builder.overrides.$entity_type_id.view",
+ 'weight' => 5,
+ 'cache_contexts' => ['layout_builder_is_active:' . $entity_type_id],
+ ];
+ // @todo This link should be conditionally displayed, see
+ // https://www.drupal.org/node/2917777.
+ $this->derivatives["layout_builder.overrides.$entity_type_id.revert"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.overrides.$entity_type_id.revert",
+ 'title' => $this->t('Revert to defaults'),
+ 'parent_id' => "layout_builder_ui:layout_builder.overrides.$entity_type_id.view",
+ 'weight' => 10,
+ 'cache_contexts' => ['layout_builder_is_active:' . $entity_type_id],
+ ];
+ }
+
+ foreach ($this->getEntityTypesForDefaults() as $entity_type_id => $entity_type) {
+ // Defaults.
+ $this->derivatives["layout_builder.defaults.$entity_type_id.view"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.defaults.$entity_type_id.view",
+ 'title' => $this->t('Manage layout'),
+ 'base_route' => "layout_builder.defaults.$entity_type_id.view",
+ ];
+ $this->derivatives["layout_builder.defaults.$entity_type_id.save"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.defaults.$entity_type_id.save",
+ 'title' => $this->t('Save Layout'),
+ 'parent_id' => "layout_builder_ui:layout_builder.defaults.$entity_type_id.view",
+ ];
+ $this->derivatives["layout_builder.defaults.$entity_type_id.cancel"] = $base_plugin_definition + [
+ 'route_name' => "layout_builder.defaults.$entity_type_id.cancel",
+ 'title' => $this->t('Cancel Layout'),
+ 'weight' => 5,
+ 'parent_id' => "layout_builder_ui:layout_builder.defaults.$entity_type_id.view",
+ ];
+ }
+
+ return $this->derivatives;
+ }
+
+ /**
+ * Returns an array of entity types relevant for defaults.
+ *
+ * @return \Drupal\Core\Entity\EntityTypeInterface[]
+ * An array of entity types.
+ */
+ protected function getEntityTypesForDefaults() {
+ return array_filter($this->entityTypeManager->getDefinitions(), function (EntityTypeInterface $entity_type) {
+ return $entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasViewBuilderClass() && $entity_type->get('field_ui_base_route');
+ });
+ }
+
+ /**
+ * Returns an array of entity types relevant for overrides.
+ *
+ * @return \Drupal\Core\Entity\EntityTypeInterface[]
+ * An array of entity types.
+ */
+ protected function getEntityTypesForOverrides() {
+ return array_filter($this->entityTypeManager->getDefinitions(), function (EntityTypeInterface $entity_type) {
+ return $entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasViewBuilderClass() && $entity_type->hasLinkTemplate('canonical');
+ });
+ }
+
+}