Entity.entity_name.collection link missing when creating a custom entity type

Question

I've been trying to programmatically create a custom entity type, yet I keep getting an error message I can't seem to figure out. Here is my code:

/src/Entity/Car.php

namespace Drupal\car\Entity;

use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\Field\BaseFieldDefinition;
use Drupal\Core\Entity\ContentEntityBase;
use Drupal\Core\Entity\EntityChangedTrait;
use Drupal\Core\Entity\EntityTypeInterface;
use Drupal\user\UserInterface;

/**
 * Defines the Car entity.
 *
 * @ContentEntityType(
 *   id = "car",
 *   label = @Translation("Car"),
 *   handlers = {
 *     "view_builder" = "Drupal\Core\Entity\EntityViewBuilder",
 *     "list_builder" = "Drupal\car\CarListBuilder",
*
 *     "form" = {
 *       "default" = "Drupal\car\Form\CarForm",
 *       "add" = "Drupal\car\Form\CarForm",
 *       "edit" = "Drupal\car\Form\CarForm",
 *       "delete" = "Drupal\car\Form\ContentEntityDeleteForm",
 *     },
 *     "route_provider" = {
  *      "html" = "Drupal\Core\Entity\Routing\AdminHtmlRouteProvider"
 *     },
 *   },
 *   base_table = "car",
 *   admin_permission = "administer site entities",
 *   entity_keys = {
 *     "id" = "id",
 *     "label" = "name",
 *     "uuid" = "uuid",
 *   },
 *   links = {
 *     "canonical" = "/admin/structure/car/{car}",
 *     "add-form" = "/admin/structure/car/add",
 *     "edit-form" = "/admin/structure/car/{car}/edit",
 *     "delete-form" = "/admin/structure/car/{car}/delete",
 *     "collection" = "/admin/structure/car",
 *   },
 * )
 */

class Car extends ContentEntityBase implements CarInterface {

  use EntityChangedTrait;

  /**
   * {@inheritdoc}
   */
  public function getName() {
    return $this->get('name')->value;
  }

  /**
   * {@inheritdoc}
   */
  public function setName($name) {
    $this->set('name', $name);
    return $this;
  }

  /**
   * {@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 car entity.'))
      ->setSettings([
        'max_length' => 50,
        'text_processing' => 0,
      ])
      ->setDefaultValue('')
      ->setDisplayOptions('view', [
        'label' => 'above',
        'type' => 'string',
        'weight' => -4,
      ])
      ->setDisplayOptions('form', [
        'type' => 'string_textfield',
        'weight' => -4,
      ])
      ->setDisplayConfigurable('form', TRUE)
      ->setDisplayConfigurable('view', TRUE)
      ->setRequired(TRUE);

    $fields['created'] = BaseFieldDefinition::create('created')
      ->setLabel(t('Created'))
      ->setDescription(t('The time that the entity was created.'));

    $fields['changed'] = BaseFieldDefinition::create('changed')
      ->setLabel(t('Changed'))
      ->setDescription(t('The time that the entity was last edited.'));

    return $fields;
  }

}

/src/Entity/CarInterface.php

namespace Drupal\car\Entity;

use Drupal\Core\Entity\ContentEntityInterface;
use Drupal\Core\Entity\EntityChangedInterface;

/**
 * Provides an interface for defining Car entities.
 */
interface CarInterface extends ContentEntityInterface, EntityChangedInterface {

  /**
   * Gets the Car name.
   *
   * @return string
   *   Name of the Car.
   */
  public function getName();

  /**
   * Sets the Car name.
   *
   * @param string $name
   *   The Car name.
   *
   * @return \Drupal\car\Entity\CarInterface
   *   The called Car entity.
   */
  public function setName($name);

}

/car.links.menu.yml

# Car menu items definition
entity.car.collection:
  title: 'Car list'
  route_name: entity.car.collection
  description: 'List Car entities'
  parent: system.admin_structure
  weight: 100

I also have src/CarListBuilder.php (content is irrelevant to the problem, I think)

The error I'm getting is:

Route "entity.car.collection" does not exist. in...

I checked in the router table and it looks like only four out of the five links ("canonical","add-form","edit-form","delete-form") were created but not "collection".

I inspected the code generated by Drupal console's generate:entity:content, yet I can't find in any of the code another place the collection link is defined apart from the annotation.

Also, another thing I noticed was that there is no "car" base_table.

What am I missing here?

Answer 1

I have just tested with Drupal 8.6 and it worked fine for me, these are the steps I went throu:

Step 1. $ drupal generate:entity:content

// Welcome to the Drupal Content Entity generator
Enter the module name [aa_11]:
> mymodule

Enter the class of your new content entity [DefaultEntity]:
> Car

Enter the machine name of your new content entity [car]:
>

Enter the label of your new content entity [Car]:
>

Enter the base-path for the content entity routes [/admin/structure]:
>

Do you want this (content) entity to have bundles? (yes/no) [no]:
> no

Is your entity translatable? (yes/no) [yes]:
> no

Is your entity revisionable? (yes/no) [yes]:
> no

Step 2. $ drupal entity-updates -y

Result file: src/CarListBuilder.php

namespace Drupal\mymodule;

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\EntityListBuilder;
use Drupal\Core\Link;

/**
 * Defines a class to build a listing of Car entities.
 *
 * @ingroup mymodule
 */
class CarListBuilder extends EntityListBuilder {


  /**
   * {@inheritdoc}
   */
  public function buildHeader() {
    $header['id'] = $this->t('Car ID');
    $header['name'] = $this->t('Name');
    return $header + parent::buildHeader();
  }

  /**
   * {@inheritdoc}
   */
  public function buildRow(EntityInterface $entity) {
    /* @var $entity \Drupal\mymodule\Entity\Car */
    $row['id'] = $entity->id();
    $row['name'] = Link::createFromRoute(
      $entity->label(),
      'entity.car.edit_form',
      ['car' => $entity->id()]
    );
    return $row + parent::buildRow($entity);
  }

}