--- /dev/null
+<?php
+
+namespace Drupal\layout_builder\Plugin\SectionStorage;
+
+use Drupal\Component\Utility\NestedArray;
+use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
+use Drupal\Core\Plugin\Context\Context;
+use Drupal\Core\Plugin\Context\ContextDefinition;
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+use Drupal\Core\Url;
+use Drupal\field_ui\FieldUI;
+use Drupal\layout_builder\DefaultsSectionStorageInterface;
+use Drupal\layout_builder\Entity\LayoutBuilderSampleEntityGenerator;
+use Drupal\layout_builder\Entity\LayoutEntityDisplayInterface;
+use Drupal\layout_builder\SectionListInterface;
+use Symfony\Component\DependencyInjection\ContainerInterface;
+use Symfony\Component\Routing\RouteCollection;
+
+/**
+ * Defines the 'defaults' section storage type.
+ *
+ * @SectionStorage(
+ * id = "defaults",
+ * )
+ *
+ * @internal
+ * Layout Builder is currently experimental and should only be leveraged by
+ * experimental modules and development releases of contributed modules.
+ * See https://www.drupal.org/core/experimental for more information.
+ */
+class DefaultsSectionStorage extends SectionStorageBase implements ContainerFactoryPluginInterface, DefaultsSectionStorageInterface {
+
+ /**
+ * The entity type manager.
+ *
+ * @var \Drupal\Core\Entity\EntityTypeManagerInterface
+ */
+ protected $entityTypeManager;
+
+ /**
+ * The entity type bundle info.
+ *
+ * @var \Drupal\Core\Entity\EntityTypeBundleInfoInterface
+ */
+ protected $entityTypeBundleInfo;
+
+ /**
+ * {@inheritdoc}
+ *
+ * @var \Drupal\layout_builder\Entity\LayoutEntityDisplayInterface
+ */
+ protected $sectionList;
+
+ /**
+ * The sample entity generator.
+ *
+ * @var \Drupal\layout_builder\Entity\LayoutBuilderSampleEntityGenerator
+ */
+ protected $sampleEntityGenerator;
+
+ /**
+ * {@inheritdoc}
+ */
+ public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info, LayoutBuilderSampleEntityGenerator $sample_entity_generator) {
+ parent::__construct($configuration, $plugin_id, $plugin_definition);
+
+ $this->entityTypeManager = $entity_type_manager;
+ $this->entityTypeBundleInfo = $entity_type_bundle_info;
+ $this->sampleEntityGenerator = $sample_entity_generator;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
+ return new static(
+ $configuration,
+ $plugin_id,
+ $plugin_definition,
+ $container->get('entity_type.manager'),
+ $container->get('entity_type.bundle.info'),
+ $container->get('layout_builder.sample_entity_generator')
+ );
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function setSectionList(SectionListInterface $section_list) {
+ if (!$section_list instanceof LayoutEntityDisplayInterface) {
+ throw new \InvalidArgumentException('Defaults expect a display-based section list');
+ }
+
+ return parent::setSectionList($section_list);
+ }
+
+ /**
+ * Gets the entity storing the overrides.
+ *
+ * @return \Drupal\layout_builder\Entity\LayoutEntityDisplayInterface
+ * The entity storing the defaults.
+ */
+ protected function getDisplay() {
+ return $this->getSectionList();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getStorageId() {
+ return $this->getDisplay()->id();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getRedirectUrl() {
+ return Url::fromRoute("entity.entity_view_display.{$this->getDisplay()->getTargetEntityTypeId()}.view_mode", $this->getRouteParameters());
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getLayoutBuilderUrl() {
+ return Url::fromRoute("layout_builder.{$this->getStorageType()}.{$this->getDisplay()->getTargetEntityTypeId()}.view", $this->getRouteParameters());
+ }
+
+ /**
+ * Provides the route parameters needed to generate a URL for this object.
+ *
+ * @return mixed[]
+ * An associative array of parameter names and values.
+ */
+ protected function getRouteParameters() {
+ $display = $this->getDisplay();
+ $entity_type = $this->entityTypeManager->getDefinition($display->getTargetEntityTypeId());
+ $route_parameters = FieldUI::getRouteBundleParameter($entity_type, $display->getTargetBundle());
+ $route_parameters['view_mode_name'] = $display->getMode();
+ return $route_parameters;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function buildRoutes(RouteCollection $collection) {
+ foreach ($this->getEntityTypes() as $entity_type_id => $entity_type) {
+ // Try to get the route from the current collection.
+ if (!$entity_route = $collection->get($entity_type->get('field_ui_base_route'))) {
+ continue;
+ }
+
+ $path = $entity_route->getPath() . '/display-layout/{view_mode_name}';
+
+ $defaults = [];
+ $defaults['entity_type_id'] = $entity_type_id;
+ // If the entity type has no bundles and it doesn't use {bundle} in its
+ // admin path, use the entity type.
+ if (strpos($path, '{bundle}') === FALSE) {
+ if (!$entity_type->hasKey('bundle')) {
+ $defaults['bundle'] = $entity_type_id;
+ }
+ else {
+ $defaults['bundle_key'] = $entity_type->getBundleEntityType();
+ }
+ }
+
+ $requirements = [];
+ $requirements['_field_ui_view_mode_access'] = 'administer ' . $entity_type_id . ' display';
+
+ $options = $entity_route->getOptions();
+ $options['_admin_route'] = FALSE;
+
+ $this->buildLayoutRoutes($collection, $this->getPluginDefinition(), $path, $defaults, $requirements, $options, $entity_type_id);
+
+ $route_names = [
+ "entity.entity_view_display.{$entity_type_id}.default",
+ "entity.entity_view_display.{$entity_type_id}.view_mode",
+ ];
+ foreach ($route_names as $route_name) {
+ if (!$route = $collection->get($route_name)) {
+ continue;
+ }
+
+ $route->addDefaults([
+ 'section_storage_type' => $this->getStorageType(),
+ 'section_storage' => '',
+ ] + $defaults);
+ $parameters['section_storage']['layout_builder_tempstore'] = TRUE;
+ $parameters = NestedArray::mergeDeep($parameters, $route->getOption('parameters') ?: []);
+ $route->setOption('parameters', $parameters);
+ }
+ }
+ }
+
+ /**
+ * Returns an array of relevant entity types.
+ *
+ * @return \Drupal\Core\Entity\EntityTypeInterface[]
+ * An array of entity types.
+ */
+ protected function getEntityTypes() {
+ return array_filter($this->entityTypeManager->getDefinitions(), function (EntityTypeInterface $entity_type) {
+ return $entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasViewBuilderClass() && $entity_type->get('field_ui_base_route');
+ });
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function extractIdFromRoute($value, $definition, $name, array $defaults) {
+ if (is_string($value) && strpos($value, '.') !== FALSE) {
+ return $value;
+ }
+
+ // If a bundle is not provided but a value corresponding to the bundle key
+ // is, use that for the bundle value.
+ if (empty($defaults['bundle']) && isset($defaults['bundle_key']) && !empty($defaults[$defaults['bundle_key']])) {
+ $defaults['bundle'] = $defaults[$defaults['bundle_key']];
+ }
+
+ if (!empty($defaults['entity_type_id']) && !empty($defaults['bundle']) && !empty($defaults['view_mode_name'])) {
+ return $defaults['entity_type_id'] . '.' . $defaults['bundle'] . '.' . $defaults['view_mode_name'];
+ }
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getSectionListFromId($id) {
+ if (strpos($id, '.') === FALSE) {
+ throw new \InvalidArgumentException(sprintf('The "%s" ID for the "%s" section storage type is invalid', $id, $this->getStorageType()));
+ }
+
+ $storage = $this->entityTypeManager->getStorage('entity_view_display');
+ // If the display does not exist, create a new one.
+ if (!$display = $storage->load($id)) {
+ list($entity_type_id, $bundle, $view_mode) = explode('.', $id, 3);
+ $display = $storage->create([
+ 'targetEntityType' => $entity_type_id,
+ 'bundle' => $bundle,
+ 'mode' => $view_mode,
+ 'status' => TRUE,
+ ]);
+ }
+ return $display;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function getContexts() {
+ $display = $this->getDisplay();
+ $entity = $this->sampleEntityGenerator->get($display->getTargetEntityTypeId(), $display->getTargetBundle());
+ $context_label = new TranslatableMarkup('@entity being viewed', ['@entity' => $entity->getEntityType()->getLabel()]);
+
+ // @todo Use EntityContextDefinition after resolving
+ // https://www.drupal.org/node/2932462.
+ $contexts = [];
+ $contexts['layout_builder.entity'] = new Context(new ContextDefinition("entity:{$entity->getEntityTypeId()}", $context_label), $entity);
+ return $contexts;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function label() {
+ return $this->getDisplay()->label();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function save() {
+ return $this->getDisplay()->save();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function isOverridable() {
+ return $this->getDisplay()->isOverridable();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function setOverridable($overridable = TRUE) {
+ $this->getDisplay()->setOverridable($overridable);
+ return $this;
+ }
+
+}