ContentEntityDeriver.php

<?php

namespace Drupal\migrate_drupal\Plugin\migrate\source;

use Drupal\Component\Plugin\Derivative\DeriverBase;
use Drupal\Core\Entity\ContentEntityTypeInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Deriver for content entity source plugins.
 */
class ContentEntityDeriver extends DeriverBase implements ContainerDeriverInterface {
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * Constructs a new ContentEntityDeriver.
     *
     * @param string $base_plugin_id
     *   The base plugin ID.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
     *   The entity type manager.
     */
    public function __construct($base_plugin_id, EntityTypeManagerInterface $entityTypeManager) {
        $this->entityTypeManager = $entityTypeManager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, $base_plugin_id) {
        return new static($base_plugin_id, $container->get('entity_type.manager'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        $this->derivatives = [];
        foreach ($this->entityTypeManager
            ->getDefinitions() as $id => $definition) {
            if ($definition instanceof ContentEntityTypeInterface) {
                $this->derivatives[$id] = $base_plugin_definition;
                // Provide entity_type so the source can be used apart from a deriver.
                $this->derivatives[$id]['entity_type'] = $id;
            }
        }
        return parent::getDerivativeDefinitions($base_plugin_definition);
    }

}