Issue #2666792 by bojanz, dawehner, edysmp, heddn: Provide a route provider for add-page of entities

core/lib/Drupal/Core/Entity/Controller/EntityController.php

@@ -7,22 +7,28 @@
 
 namespace Drupal\Core\Entity\Controller;
 
+use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityRepositoryInterface;
 use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Link;
+use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
-use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Routing\UrlGeneratorInterface;
+use Drupal\Core\Routing\UrlGeneratorTrait;
 use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\StringTranslation\TranslationInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
- * Provides generic entity title callbacks for use in routing.
+ * Provides the add-page and title callbacks for entities.
  *
  * It provides:
- * - An add title callback for entities without bundles.
- * - An add title callback for entities with bundles.
+ * - The add-page callback.
+ * - An add title callback for entity types.
+ * - An add title callback for entity types with bundles.
  * - A view title callback.
  * - An edit title callback.
  * - A delete title callback.
@@ -30,6 +36,7 @@ use Symfony\Component\DependencyInjection\ContainerInterface;
 class EntityController implements ContainerInjectionInterface {
 
   use StringTranslationTrait;
+  use UrlGeneratorTrait;
 
   /**
    * The entity manager.
@@ -52,6 +59,13 @@ class EntityController implements ContainerInjectionInterface {
    */
   protected $entityRepository;
 
+  /**
+   * The renderer.
+   *
+   * @var \Drupal\Core\Render\RendererInterface
+   */
+  protected $renderer;
+
   /**
    * Constructs a new EntityController.
    *
@@ -61,14 +75,20 @@ class EntityController implements ContainerInjectionInterface {
    *   The entity type bundle info.
    * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
    *   The entity repository.
+   * @param \Drupal\Core\Render\RendererInterface $renderer
+   *   The renderer.
    * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
    *   The string translation.
+   * @param \Drupal\Core\Routing\UrlGeneratorInterface $url_generator
+   *   The url generator.
    */
-  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info, EntityRepositoryInterface $entity_repository, TranslationInterface $string_translation) {
+  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info, EntityRepositoryInterface $entity_repository, RendererInterface $renderer, TranslationInterface $string_translation, UrlGeneratorInterface $url_generator) {
     $this->entityTypeManager = $entity_type_manager;
     $this->entityTypeBundleInfo = $entity_type_bundle_info;
     $this->entityRepository = $entity_repository;
+    $this->renderer = $renderer;
     $this->stringTranslation = $string_translation;
+    $this->urlGenerator = $url_generator;
   }
 
   /**
@@ -79,12 +99,83 @@ class EntityController implements ContainerInjectionInterface {
       $container->get('entity_type.manager'),
       $container->get('entity_type.bundle.info'),
       $container->get('entity.repository'),
-      $container->get('string_translation')
+      $container->get('renderer'),
+      $container->get('string_translation'),
+      $container->get('url_generator')
     );
   }
 
   /**
-   * Provides a generic add title callback for entities without bundles.
+   * Displays add links for the available bundles.
+   *
+   * Redirects to the add form if there's only one bundle available.
+   *
+   * @param string $entity_type_id
+   *   The entity type ID.
+   *
+   * @return \Symfony\Component\HttpFoundation\RedirectResponse|array
+   *   If there's only one available bundle, a redirect response.
+   *   Otherwise, a render array with the add links for each bundle.
+   */
+  public function addPage($entity_type_id) {
+    $entity_type = $this->entityTypeManager->getDefinition($entity_type_id);
+    $bundles = $this->entityTypeBundleInfo->getBundleInfo($entity_type_id);
+    $bundle_key = $entity_type->getKey('bundle');
+    $bundle_entity_type_id = $entity_type->getBundleEntityType();
+    $build = [
+      '#theme' => 'entity_add_list',
+      '#bundles' => [],
+    ];
+    if ($bundle_entity_type_id) {
+      $bundle_argument = $bundle_entity_type_id;
+      $bundle_entity_type = $this->entityTypeManager->getDefinition($bundle_entity_type_id);
+      $bundle_entity_type_label = $bundle_entity_type->getLowercaseLabel();
+      $build['#cache']['tags'] = $bundle_entity_type->getListCacheTags();
+
+      // Build the message shown when there are no bundles.
+      $link_text = $this->t('Add a new @entity_type.', ['@entity_type' => $bundle_entity_type_label]);
+      $link_route_name = 'entity.' . $bundle_entity_type->id() . '.add_form';
+      $build['#add_bundle_message'] = $this->t('There is no @entity_type yet. @add_link', [
+        '@entity_type' => $bundle_entity_type_label,
+        '@add_link' => Link::createFromRoute($link_text, $link_route_name)->toString(),
+      ]);
+      // Filter out the bundles the user doesn't have access to.
+      $access_control_handler = $this->entityTypeManager->getAccessControlHandler($bundle_entity_type_id);
+      foreach ($bundles as $bundle_name => $bundle_info) {
+        $access = $access_control_handler->createAccess($bundle_name, NULL, [], TRUE);
+        if (!$access->isAllowed()) {
+          unset($bundles[$bundle_name]);
+        }
+        $this->renderer->addCacheableDependency($build, $access);
+      }
+      // Add descriptions from the bundle entities.
+      $bundles = $this->loadBundleDescriptions($bundles, $bundle_entity_type);
+    }
+    else {
+      $bundle_argument = $bundle_key;
+    }
+
+    $form_route_name = 'entity.' . $entity_type_id . '.add_form';
+    // Redirect if there's only one bundle available.
+    if (count($bundles) == 1) {
+      $bundle_names = array_keys($bundles);
+      $bundle_name = reset($bundle_names);
+      return $this->redirect($form_route_name, [$bundle_argument => $bundle_name]);
+    }
+    // Prepare the #bundles array for the template.
+    foreach ($bundles as $bundle_name => $bundle_info) {
+      $build['#bundles'][$bundle_name] = [
+        'label' => $bundle_info['label'],
+        'description' => isset($bundle_info['description']) ? $bundle_info['description'] : '',
+        'add_link' => Link::createFromRoute($bundle_info['label'], $form_route_name, [$bundle_argument => $bundle_name]),
+      ];
+    }
+
+    return $build;
+  }
+
+  /**
+   * Provides a generic add title callback for an entity type.
    *
    * @param string $entity_type_id
    *   The entity type ID.
@@ -209,4 +300,32 @@ class EntityController implements ContainerInjectionInterface {
     }
   }
 
+  /**
+   * Expands the bundle information with descriptions, if known.
+   *
+   * @param array $bundles
+   *   An array of bundle information.
+   * @param \Drupal\Core\Entity\EntityTypeInterface $bundle_entity_type
+   *   The ID of the bundle entity type.
+   *
+   * @return array
+   *   The expanded array of bundle information.
+   */
+  protected function loadBundleDescriptions(array $bundles, EntityTypeInterface $bundle_entity_type) {
+    if (!$bundle_entity_type->isSubclassOf('\Drupal\Core\Entity\EntityDescriptionInterface')) {
+      return $bundles;
+    }
+    $bundle_names = array_keys($bundles);
+    $storage = $this->entityTypeManager->getStorage($bundle_entity_type->id());
+    /** @var \Drupal\Core\Entity\EntityDescriptionInterface[] $bundle_entities */
+    $bundle_entities = $storage->loadMultiple($bundle_names);
+    foreach ($bundles as $bundle_name => &$bundle_info) {
+      if (isset($bundle_entities[$bundle_name])) {
+        $bundle_info['description'] = $bundle_entities[$bundle_name]->getDescription();
+      }
+    }
+
+    return $bundles;
+  }
+
 }

core/lib/Drupal/Core/Entity/EntityDescriptionInterface.php

@@ -0,0 +1,33 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Entity\EntityDescriptionInterface.
+ */
+
+namespace Drupal\Core\Entity;
+
+/**
+ * Defines the interface for entities that have a description.
+ */
+interface EntityDescriptionInterface {
+
+  /**
+   * Gets the entity description.
+   *
+   * @return string
+   *   The entity description.
+   */
+  public function getDescription();
+
+  /**
+   * Sets the entity description.
+   *
+   * @param string $description
+   *   The entity description.
+   *
+   * @return $this
+   */
+  public function setDescription($description);
+
+}

core/lib/Drupal/Core/Entity/Routing/AdminHtmlRouteProvider.php

@@ -10,9 +10,9 @@ namespace Drupal\Core\Entity\Routing;
 use Drupal\Core\Entity\EntityTypeInterface;
 
 /**
- * Provides HTML routes for entities with administrative edit/delete pages.
+ * Provides HTML routes for entities with administrative add/edit/delete pages.
  *
- * Use this class if the edit and delete form routes should use the
+ * Use this class if the add/edit/delete form routes should use the
  * administrative theme.
  *
  * @see \Drupal\Core\Entity\Routing\DefaultHtmlRouteProvider.
@@ -21,6 +21,16 @@ use Drupal\Core\Entity\EntityTypeInterface;
  */
 class AdminHtmlRouteProvider extends DefaultHtmlRouteProvider {
 
+  /**
+   * {@inheritdoc}
+   */
+  protected function getAddPageRoute(EntityTypeInterface $entity_type) {
+    if ($route = parent::getAddPageRoute($entity_type)) {
+      $route->setOption('_admin_route', TRUE);
+      return $route;
+    }
+  }
+
   /**
    * {@inheritdoc}
    */

core/lib/Drupal/Core/Entity/Routing/DefaultHtmlRouteProvider.php

@@ -24,6 +24,8 @@ use Symfony\Component\Routing\RouteCollection;
  * This class provides the following routes for entities, with title and access
  * callbacks:
  * - canonical
+ * - add-page
+ * - add-form
  * - edit-form
  * - delete-form
  *
@@ -78,8 +80,12 @@ class DefaultHtmlRouteProvider implements EntityRouteProviderInterface, EntityHa
 
     $entity_type_id = $entity_type->id();
 
-    if ($add_route = $this->getAddFormRoute($entity_type)) {
-      $collection->add("entity.{$entity_type_id}.add_form", $add_route);
+    if ($add_page_route = $this->getAddPageRoute($entity_type)) {
+      $collection->add("entity.{$entity_type_id}.add_page", $add_page_route);
+    }
+
+    if ($add_form_route = $this->getAddFormRoute($entity_type)) {
+      $collection->add("entity.{$entity_type_id}.add_form", $add_form_route);
     }
 
     if ($canonical_route = $this->getCanonicalRoute($entity_type)) {
@@ -97,6 +103,29 @@ class DefaultHtmlRouteProvider implements EntityRouteProviderInterface, EntityHa
     return $collection;
   }
 
+  /**
+   * Gets the add page route.
+   *
+   * Built only for entity types that have bundles.
+   *
+   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
+   *   The entity type.
+   *
+   * @return \Symfony\Component\Routing\Route|null
+   *   The generated route, if available.
+   */
+  protected function getAddPageRoute(EntityTypeInterface $entity_type) {
+    if ($entity_type->hasLinkTemplate('add-page') && $entity_type->getKey('bundle')) {
+      $route = new Route($entity_type->getLinkTemplate('add-page'));
+      $route->setDefault('_controller', EntityController::class . '::addPage');
+      $route->setDefault('_title_callback', EntityController::class . '::addTitle');
+      $route->setDefault('entity_type_id', $entity_type->id());
+      $route->setRequirement('_entity_create_access', $entity_type->id());
+
+      return $route;
+    }
+  }
+
   /**
    * Gets the add-form route.
    *

core/modules/system/src/Tests/Entity/EntityAddUITest.php

@@ -0,0 +1,107 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\system\Tests\Entity\EntityAddUITest.
+ */
+
+namespace Drupal\system\Tests\Entity;
+
+use Drupal\entity_test\Entity\EntityTestBundle;
+use Drupal\entity_test\Entity\EntityTestMul;
+use Drupal\entity_test\Entity\EntityTestWithBundle;
+use Drupal\simpletest\WebTestBase;
+use Drupal\system\Tests\Cache\AssertPageCacheContextsAndTagsTrait;
+
+/**
+ * Tests the /add and /add/{type} controllers.
+ *
+ * @group entity
+ */
+class EntityAddUITest extends WebTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['entity_test'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $web_user = $this->drupalCreateUser([
+      "administer entity_test_with_bundle content",
+      "administer entity_test content",
+    ]);
+    $this->drupalLogin($web_user);
+  }
+
+  /**
+   * Tests the add page for an entity type using bundle entities.
+   */
+  public function testAddPageWithBundleEntities() {
+    $this->drupalGet('/entity_test_with_bundle/add');
+    // No bundles exist, the add bundle message should be present.
+    $this->assertText('There is no test entity bundle yet.');
+    $this->assertLink('Add a new test entity bundle.');
+
+    // One bundle exists, confirm redirection to the add-form.
+    EntityTestBundle::create([
+      'id' => 'test',
+      'label' => 'Test label',
+      'description' => 'My test description',
+    ])->save();
+    $this->drupalGet('/entity_test_with_bundle/add');
+    $this->assertUrl('/entity_test_with_bundle/add/test');
+
+    // Two bundles exist, confirm both are shown.
+    EntityTestBundle::create([
+      'id' => 'test2',
+      'label' => 'Test2 label',
+      'description' => 'My test2 description',
+    ])->save();
+    $this->drupalGet('/entity_test_with_bundle/add');
+
+    $this->assertLink('Test label');
+    $this->assertLink('Test2 label');
+    $this->assertText('My test description');
+    $this->assertText('My test2 description');
+
+    $this->clickLink('Test2 label');
+    $this->drupalGet('/entity_test_with_bundle/add/test2');
+
+    $this->drupalPostForm(NULL, ['name[0][value]' => 'test name'], t('Save'));
+    $entity = EntityTestWithBundle::load(1);
+    $this->assertEqual('test name', $entity->label());
+  }
+
+  /**
+   * Tests the add page for an entity type not using bundle entities.
+   */
+  public function testAddPageWithoutBundleEntities() {
+    entity_test_create_bundle('test', 'Test label', 'entity_test_mul');
+    // Delete the default bundle, so that we can rely on our own.
+    entity_test_delete_bundle('entity_test_mul', 'entity_test_mul');
+
+    // One bundle exists, confirm redirection to the add-form.
+    $this->drupalGet('/entity_test_mul/add');
+    $this->assertUrl('/entity_test_mul/add/test');
+
+    // Two bundles exist, confirm both are shown.
+    entity_test_create_bundle('test2', 'Test2 label', 'entity_test_mul');
+    $this->drupalGet('/entity_test_mul/add');
+
+    $this->assertLink('Test label');
+    $this->assertLink('Test2 label');
+
+    $this->clickLink('Test2 label');
+    $this->drupalGet('/entity_test_mul/add/test2');
+
+    $this->drupalPostForm(NULL, ['name[0][value]' => 'test name'], t('Save'));
+    $entity = EntityTestMul::load(1);
+    $this->assertEqual('test name', $entity->label());
+  }
+
+}

core/modules/system/system.module

@@ -217,6 +217,13 @@ function system_theme() {
       'variables' => array('menu_items' => NULL),
       'file' => 'system.admin.inc',
     ),
+    'entity_add_list' => array(
+      'variables' => array(
+        'bundles' => array(),
+        'add_bundle_message' => NULL,
+      ),
+      'template' => 'entity-add-list',
+    ),
   ));
 }
 
@@ -316,6 +323,25 @@ function system_theme_suggestions_field(array $variables) {
   return $suggestions;
 }
 
+/**
+ * Prepares variables for the list of available bundles.
+ *
+ * Default template: entity-add-list.html.twig.
+ *
+ * @param array $variables
+ *   An associative array containing:
+ *   - bundles: An array of bundles with the label, description, add_link keys.
+ *   - add_bundle_message: The message shown when there are no bundles. Only
++ *                         available if the entity type uses bundle entities.
+ */
+function template_preprocess_entity_add_list(&$variables) {
+  foreach ($variables['bundles'] as $bundle_name => $bundle_info) {
+    $variables['bundles'][$bundle_name]['description'] = [
+      '#markup' => $bundle_info['description'],
+    ];
+  }
+}
+
 /**
  * @defgroup authorize Authorized operations
  * @{

core/modules/system/templates/entity-add-list.html.twig

@@ -0,0 +1,30 @@
+{#
+/**
+ * @file
+ * Default theme implementation to present a list of available bundles.
+ *
+ * Available variables:
+ *   - bundles: A list of bundles, each with the following properties:
+ *     - label: Bundle label.
+ *     - description: Bundle description.
+ *     - add_link: Link to create an entity of this bundle.
+ *   - add_bundle_message: The message shown when there are no bundles. Only
+ *                         available if the entity type uses bundle entities.
+ *
+ * @see template_preprocess_entity_add_list()
+ *
+ * @ingroup themeable
+ */
+#}
+{% if bundles is not empty %}
+  <dl>
+    {% for bundle in bundles %}
+      <dt>{{ bundle.add_link }}</dt>
+      <dd>{{ bundle.description }}</dd>
+    {% endfor %}
+  </dl>
+{% elseif add_bundle_message is not empty %}
+  <p>
+    {{ add_bundle_message }}
+  </p>
+{% endif %}

core/modules/system/tests/modules/entity_test/config/schema/entity_test.schema.yml

@@ -13,3 +13,17 @@ field.storage_settings.shape:
     foreign_key_name:
       type: string
       label: 'Foreign key name'
+
+entity_test.entity_test_bundle.*:
+  type: config_entity
+  label: 'Entity test bundle'
+  mapping:
+    label:
+      type: label
+      label: 'Label'
+    id:
+      type: string
+      label: 'Machine-readable name'
+    description:
+      type: text
+      label: 'Description'

core/modules/system/tests/modules/entity_test/entity_test.module

@@ -196,7 +196,7 @@ function entity_test_entity_bundle_info() {
   $bundles = array();
   $entity_types = \Drupal::entityManager()->getDefinitions();
   foreach ($entity_types as $entity_type_id => $entity_type) {
-    if ($entity_type->getProvider() == 'entity_test') {
+    if ($entity_type->getProvider() == 'entity_test' && $entity_type_id != 'entity_test_with_bundle') {
       $bundles[$entity_type_id] = \Drupal::state()->get($entity_type_id . '.bundles') ?: array($entity_type_id => array('label' => 'Entity Test Bundle'));
     }
   }

core/modules/system/tests/modules/entity_test/entity_test.permissions.yml

@@ -7,3 +7,6 @@ view test entity translations:
   title: 'View translations of test entities'
 view test entity field:
   title: 'View test entity field'
+administer entity_test_with_bundle content:
+  title: 'administer entity_test_with_bundle content'
+  description: 'administer entity_test_with_bundle content'

core/modules/system/tests/modules/entity_test/src/Entity/EntityTestBundle.php

@@ -0,0 +1,83 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\entity_test\Entity\EntityTestBundle.
+ */
+
+namespace Drupal\entity_test\Entity;
+
+use Drupal\Core\Config\Entity\ConfigEntityBundleBase;
+use Drupal\Core\Entity\EntityDescriptionInterface;
+
+/**
+ * Defines the Test entity bundle configuration entity.
+ *
+ * @ConfigEntityType(
+ *   id = "entity_test_bundle",
+ *   label = @Translation("Test entity bundle"),
+ *   handlers = {
+ *     "access" = "\Drupal\Core\Entity\EntityAccessControlHandler",
+ *     "form" = {
+ *       "default" = "\Drupal\Core\Entity\BundleEntityFormBase",
+ *     },
+ *     "route_provider" = {
+ *       "html" = "Drupal\Core\Entity\Routing\DefaultHtmlRouteProvider",
+ *     },
+ *   },
+ *   admin_permission = "administer entity_test_with_bundle content",
+ *   config_prefix = "entity_test_bundle",
+ *   bundle_of = "entity_test_with_bundle",
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "label" = "label"
+ *   },
+ *   config_export = {
+ *     "id",
+ *     "label",
+ *     "description",
+ *   },
+ *   links = {
+ *     "add-form" = "/entity_test_bundle/add",
+ *   }
+ * )
+ */
+class EntityTestBundle extends ConfigEntityBundleBase implements EntityDescriptionInterface {
+
+  /**
+   * The machine name.
+   *
+   * @var string
+   */
+  protected $id;
+
+  /**
+   * The human-readable name.
+   *
+   * @var string
+   */
+  protected $label;
+
+  /**
+   * The description.
+   *
+   * @var string
+   */
+  protected $description;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getDescription() {
+    return $this->description;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function setDescription($description) {
+    $this->description = $description;
+    return $this;
+  }
+
+}

core/modules/system/tests/modules/entity_test/src/Entity/EntityTestMul.php

@@ -38,7 +38,8 @@ namespace Drupal\entity_test\Entity;
  *     "langcode" = "langcode",
  *   },
  *   links = {
- *     "add-form" = "/entity_test_mul/add",
+ *     "add-page" = "/entity_test_mul/add",
+ *     "add-form" = "/entity_test_mul/add/{type}",
  *     "canonical" = "/entity_test_mul/manage/{entity_test_mul}",
  *     "edit-form" = "/entity_test_mul/manage/{entity_test_mul}/edit",
  *     "delete-form" = "/entity_test/delete/entity_test_mul/{entity_test_mul}",

core/modules/system/tests/modules/entity_test/src/Entity/EntityTestWithBundle.php

@@ -0,0 +1,77 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\entity_test\Entity\EntityTestWithBundle.
+ */
+
+namespace Drupal\entity_test\Entity;
+
+use Drupal\Core\Entity\ContentEntityBase;
+use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Field\BaseFieldDefinition;
+
+/**
+ * Defines the Test entity with bundle entity class.
+ *
+ * @ContentEntityType(
+ *   id = "entity_test_with_bundle",
+ *   label = @Translation("Test entity with bundle"),
+ *   handlers = {
+ *     "list_builder" = "Drupal\entity_test\EntityTestListBuilder",
+ *     "view_builder" = "Drupal\entity_test\EntityTestViewBuilder",
+ *     "access" = "\Drupal\Core\Entity\EntityAccessControlHandler",
+ *     "form" = {
+ *       "default" = "\Drupal\Core\Entity\ContentEntityForm",
+ *       "delete" = "\Drupal\Core\Entity\EntityDeleteForm"
+ *     },
+ *     "route_provider" = {
+ *       "html" = "Drupal\Core\Entity\Routing\DefaultHtmlRouteProvider",
+ *     },
+ *   },
+ *   base_table = "entity_test_with_bundle",
+ *   admin_permission = "administer entity_test_with_bundle content",
+ *   persistent_cache = FALSE,
+ *   entity_keys = {
+ *     "id" = "id",
+ *     "uuid" = "uuid",
+ *     "bundle" = "type",
+ *     "label" = "name",
+ *     "langcode" = "langcode",
+ *   },
+ *   bundle_entity_type = "entity_test_bundle",
+ *   links = {
+ *     "canonical" = "/entity_test_with_bundle/{entity_test_with_bundle}",
+ *     "add-page" = "/entity_test_with_bundle/add",
+ *     "add-form" = "/entity_test_with_bundle/add/{entity_test_bundle}",
+ *     "edit-form" = "/entity_test_with_bundle/manage/{entity_test_with_bundle}/edit",
+ *     "delete-form" = "/entity_test_with_bundle/delete/entity_test_with_bundle/{entity_test_with_bundle}",
+ *   },
+ * )
+ */
+class EntityTestWithBundle extends ContentEntityBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
+    $fields = parent::baseFieldDefinitions($entity_type);
+
+    $fields['name'] = BaseFieldDefinition::create('string')
+      ->setLabel(t('Name'))
+      ->setDescription(t('The name of the test entity.'))
+      ->setTranslatable(TRUE)
+      ->setSetting('max_length', 32)
+      ->setDisplayOptions('view', [
+        'label' => 'hidden',
+        'type' => 'string',
+        'weight' => -5,
+      ])
+      ->setDisplayOptions('form', [
+        'type' => 'string_textfield',
+        'weight' => -5,
+      ]);
+    return $fields;
+  }
+
+}

core/modules/system/tests/modules/entity_test/src/Routing/EntityTestRoutes.php

@@ -25,11 +25,6 @@ class EntityTestRoutes {
 
     $routes = array();
     foreach ($types as $entity_type_id) {
-      $routes["entity.$entity_type_id.add_form"] = new Route(
-        "$entity_type_id/add",
-        array('_entity_form' => "$entity_type_id.default"),
-        array('_permission' => 'administer entity_test content')
-      );
       $routes["entity.$entity_type_id.admin_form"] = new Route(
         "$entity_type_id/structure/{bundle}",
         array('_controller' => '\Drupal\entity_test\Controller\EntityTestController::testAdmin'),

core/tests/Drupal/Tests/Core/Entity/Routing/DefaultHtmlRouteProviderTest.php

@@ -58,6 +58,44 @@ class DefaultHtmlRouteProviderTest extends UnitTestCase {
     $this->routeProvider = new TestDefaultHtmlRouteProvider($this->entityTypeManager->reveal(), $this->entityFieldManager->reveal());
   }
 
+  /**
+   * @covers ::getAddPageRoute
+   * @dataProvider providerTestGetAddPageRoute
+   */
+  public function testGetAddPageRoute(Route $expected = NULL, EntityTypeInterface $entity_type) {
+    $route = $this->routeProvider->getAddPageRoute($entity_type);
+    $this->assertEquals($expected, $route);
+  }
+
+  public function providerTestGetAddPageRoute() {
+    $data = [];
+
+    $entity_type1 = $this->getEntityType();
+    $entity_type1->hasLinkTemplate('add-page')->willReturn(FALSE);
+    $data['no_add_page_link_template'] = [NULL, $entity_type1->reveal()];
+
+    $entity_type2 = $this->getEntityType();
+    $entity_type2->hasLinkTemplate('add-page')->willReturn(TRUE);
+    $entity_type2->getKey('bundle')->willReturn(NULL);
+    $data['no_bundle'] = [NULL, $entity_type2->reveal()];
+
+    $entity_type3 = $this->getEntityType();
+    $entity_type3->hasLinkTemplate('add-page')->willReturn(TRUE);
+    $entity_type3->getLinkTemplate('add-page')->willReturn('/the/add/page/link/template');
+    $entity_type3->id()->willReturn('the_entity_type_id');
+    $entity_type3->getKey('bundle')->willReturn('type');
+    $route = new Route('/the/add/page/link/template');
+    $route->setDefaults([
+      '_controller' => 'Drupal\Core\Entity\Controller\EntityController::addPage',
+      '_title_callback' => 'Drupal\Core\Entity\Controller\EntityController::addTitle',
+      'entity_type_id' => 'the_entity_type_id',
+    ]);
+    $route->setRequirement('_entity_create_access', 'the_entity_type_id');
+    $data['add_page'] = [clone $route, $entity_type3->reveal()];
+
+    return $data;
+  }
+
   /**
    * @covers ::getAddFormRoute
    * @dataProvider providerTestGetAddFormRoute
@@ -260,6 +298,9 @@ class TestDefaultHtmlRouteProvider extends DefaultHtmlRouteProvider {
   public function getEntityTypeIdKeyType(EntityTypeInterface $entity_type) {
     return parent::getEntityTypeIdKeyType($entity_type);
   }
+  public function getAddPageRoute(EntityTypeInterface $entity_type) {
+    return parent::getAddPageRoute($entity_type);
+  }
   public function getAddFormRoute(EntityTypeInterface $entity_type) {
     return parent::getAddFormRoute($entity_type);
   }

core/themes/seven/templates/entity-add-list.html.twig

@@ -0,0 +1,27 @@
+{#
+/**
+ * @file
+ * Theme override to to present a list of available bundles.
+ *
+ * Available variables:
+ *   - bundles: A list of bundles, each with the following properties:
+ *     - label: Bundle label.
+ *     - description: Bundle description.
+ *     - add_link: Link to create an entity of this bundle.
+ *   - add_bundle_message: The message shown when there are no bundles. Only
+ *                         available if the entity type uses bundle entities.
+ *
+ * @see template_preprocess_entity_add_list()
+ */
+#}
+{% if bundles is not empty %}
+  <ul class="admin-list">
+    {% for bundle in bundles %}
+      <li class="clearfix"><a href="{{ bundle.add_link.url }}"><span class="label">{{ bundle.label }}</span><div class="description">{{ bundle.description }}</div></a></li>
+    {% endfor %}
+  </ul>
+{% elseif add_bundle_message is not empty %}
+  <p>
+    {{ add_bundle_message }}
+  </p>
+{% endif %}

core/themes/stable/templates/content-edit/entity-add-list.html.twig

@@ -0,0 +1,30 @@
+{#
+/**
+ * @file
+ * Default theme implementation to present a list of available bundles.
+ *
+ * Available variables:
+ *   - bundles: A list of bundles, each with the following properties:
+ *     - label: Bundle label.
+ *     - description: Bundle description.
+ *     - add_link: Link to create an entity of this bundle.
+ *   - add_bundle_message: The message shown when there are no bundles. Only
+ *                         available if the entity type uses bundle entities.
+ *
+ * @see template_preprocess_entity_add_list()
+ *
+ * @ingroup themeable
+ */
+#}
+{% if bundles is not empty %}
+  <dl>
+    {% for bundle in bundles %}
+      <dt>{{ bundle.add_link }}</dt>
+      <dd>{{ bundle.description }}</dd>
+    {% endfor %}
+  </dl>
+{% elseif add_bundle_message is not empty %}
+  <p>
+    {{ add_bundle_message }}
+  </p>
+{% endif %}