EntityActionDeriverBase.php

<?php

namespace Drupal\Core\Action\Plugin\Action\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;
use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
use Drupal\Core\Entity\EntityTypeInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\StringTranslation\TranslationInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides a base action for each entity type with specific interfaces.
 */
abstract class EntityActionDeriverBase extends DeriverBase implements ContainerDeriverInterface {
    use StringTranslationTrait;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * Constructs a new EntityActionDeriverBase object.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
     *   The string translation service.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, TranslationInterface $string_translation) {
        $this->entityTypeManager = $entity_type_manager;
        $this->stringTranslation = $string_translation;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, $base_plugin_id) {
        return new static($container->get('entity_type.manager'), $container->get('string_translation'));
    }
    
    /**
     * Indicates whether the deriver can be used for the provided entity type.
     *
     * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
     *   The entity type.
     *
     * @return bool
     *   TRUE if the entity type can be used, FALSE otherwise.
     */
    protected abstract function isApplicable(EntityTypeInterface $entity_type);
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        if (empty($this->derivatives)) {
            $definitions = [];
            foreach ($this->getApplicableEntityTypes() as $entity_type_id => $entity_type) {
                $definition = $base_plugin_definition;
                $definition['type'] = $entity_type_id;
                $definition['label'] = sprintf('%s %s', $base_plugin_definition['action_label'], $entity_type->getSingularLabel());
                $definitions[$entity_type_id] = $definition;
            }
            $this->derivatives = $definitions;
        }
        return parent::getDerivativeDefinitions($base_plugin_definition);
    }
    
    /**
     * Gets a list of applicable entity types.
     *
     * The list consists of all entity types which match the conditions for the
     * given deriver.
     * For example, if the action applies to entities that are publishable,
     * this method will find all entity types that are publishable.
     *
     * @return \Drupal\Core\Entity\EntityTypeInterface[]
     *   The applicable entity types, keyed by entity type ID.
     */
    protected function getApplicableEntityTypes() {
        $entity_types = $this->entityTypeManager
            ->getDefinitions();
        $entity_types = array_filter($entity_types, function (EntityTypeInterface $entity_type) {
            return $this->isApplicable($entity_type);
        });
        return $entity_types;
    }

}