View source  
  <?php
namespace Drupal\media_migration\Plugin\migrate;
use Drupal\Core\Database\DatabaseExceptionWrapper;
use Drupal\Core\Plugin\PluginBase;
use Drupal\media_migration\FileEntityDealerManagerInterface;
use Drupal\media_migration\FileEntityDealerPluginInterface;
use Drupal\media_migration\MediaMigration;
use Drupal\media_migration\Plugin\migrate\source\d7\ConfigSourceBase;
use Drupal\migrate\Exception\RequirementsException;
use Drupal\migrate\Plugin\Migration;
use Drupal\migrate\Row;
use Drupal\migrate_drupal\FieldDiscoveryInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;
class D7FileEntityDeriver extends D7FileEntityConfigDeriver {
  
  protected $basePluginId;
  
  protected $fieldPluginManager;
  
  protected $entityTypeManager;
  
  protected $fieldDiscovery;
  
  protected $fileEntityDealerManager;
  
  public function __construct(FileEntityDealerManagerInterface $file_entity_dealer_manager, FieldDiscoveryInterface $field_discovery) {
    parent::__construct($file_entity_dealer_manager);
    $this->fieldDiscovery = $field_discovery;
  }
  
  public static function create(ContainerInterface $container, $base_plugin_id) {
    return new static($container
      ->get('plugin.manager.file_entity_dealer'), $container
      ->get('migrate_drupal.field_discovery'));
  }
  
  public function getDerivativeDefinitions($base_plugin_definition) {
    $file_entity_types = static::getSourcePlugin('d7_file_entity_type');
    try {
      $file_entity_types
        ->checkRequirements();
    } catch (RequirementsException $e) {
      return $this->derivatives;
    }
    try {
      foreach ($file_entity_types as $file_entity_type_row) {
        assert($file_entity_type_row instanceof Row);
        [
          'types' => $types,
          'schemes' => $schemes,
        ] = $file_entity_type_row
          ->getSource();
        foreach (explode(ConfigSourceBase::MULTIPLE_SEPARATOR, $types) as $type) {
          foreach (explode(ConfigSourceBase::MULTIPLE_SEPARATOR, $schemes) as $scheme) {
            $dealer_plugin = $this->fileEntityDealerManager
              ->createInstanceFromTypeAndScheme($type, $scheme);
            
            if (!$dealer_plugin instanceof FileEntityDealerPluginInterface) {
              throw new \LogicException(sprintf('No FileEntityDealer plugin applies for file entities with type "%s" and with scheme "%s/*"', $type, $scheme));
            }
            $destination_media_type_id = $dealer_plugin
              ->getDestinationMediaTypeId();
            $derivative_definition = $base_plugin_definition;
            $derivative_id = implode(PluginBase::DERIVATIVE_SEPARATOR, [
              $type,
              $scheme,
            ]);
            
            $derivative_definition['migration_tags'][] = MediaMigration::MIGRATION_TAG_MAIN;
            $derivative_definition['migration_tags'][] = MediaMigration::MIGRATION_TAG_CONTENT;
            $derivative_definition['source']['type'] = $type;
            $derivative_definition['source']['scheme'] = $scheme;
            $derivative_definition['source']['destination_media_type_id'] = $destination_media_type_id;
            $derivative_definition['label'] = $this
              ->t('@label (@type)', [
              '@label' => $base_plugin_definition['label'],
              '@type' => $dealer_plugin
                ->getDestinationMediaTypeLabel(),
            ]);
            
            $derived_migration_ids = [
              'd7_file_entity_type',
              'd7_file_entity_source_field',
              'd7_file_entity_source_field_config',
              'd7_file_entity_widget',
              'd7_file_entity_formatter',
            ];
            foreach ($derived_migration_ids as $derived_migration_base_id) {
              $required_dependencies = !empty($derivative_definition['migration_dependencies']['required']) ? $derivative_definition['migration_dependencies']['required'] : [];
              $dependency_key = array_search($derived_migration_base_id, $required_dependencies, TRUE);
              if ($dependency_key !== FALSE) {
                $derivative_definition['migration_dependencies']['required'][$dependency_key] .= PluginBase::DERIVATIVE_SEPARATOR . $destination_media_type_id;
              }
            }
            
            $migration = \Drupal::service('plugin.manager.migration')
              ->createStubMigration($derivative_definition);
            $process_keys_before = array_keys($derivative_definition['process']);
            assert($migration instanceof Migration);
            $this->fieldDiscovery
              ->addBundleFieldProcesses($migration, 'file', $type);
            $derivative_definition = $migration
              ->getPluginDefinition();
            if (!empty(array_diff(array_keys($derivative_definition['process']), $process_keys_before))) {
              $derivative_definition['migration_dependencies']['required'][] = 'd7_field_instance';
            }
            
            switch ($scheme) {
              case 'public':
                $derivative_definition['migration_dependencies']['required'][] = 'd7_file';
                break;
              case 'private':
                $derivative_definition['migration_dependencies']['required'][] = 'd7_file_private';
                break;
            }
            $dealer_plugin
              ->alterMediaEntityMigrationDefinition($derivative_definition, $file_entity_types
              ->getDatabase());
            $this->derivatives[$derivative_id] = $derivative_definition;
          }
        }
      }
    } catch (DatabaseExceptionWrapper $e) {
      
    }
    return $this->derivatives;
  }
}