class D7TaxonomyTermDeriver

class D7TaxonomyTermDeriver extends DeriverBase implements ContainerDeriverInterface {
    use MigrationDeriverTrait;
    use StringTranslationTrait;
    
    /**
     * The base plugin ID this derivative is for.
     *
     * @var string
     */
    protected $basePluginId;
    
    /**
     * The migration field discovery service.
     *
     * @var \Drupal\migrate_drupal\FieldDiscoveryInterface
     */
    protected $fieldDiscovery;
    
    /**
     * D7TaxonomyTermDeriver constructor.
     *
     * @param string $base_plugin_id
     *   The base plugin ID for the plugin ID.
     * @param \Drupal\migrate_drupal\FieldDiscoveryInterface $field_discovery
     *   The migration field discovery service.
     */
    public function __construct($base_plugin_id, FieldDiscoveryInterface $field_discovery) {
        $this->basePluginId = $base_plugin_id;
        $this->fieldDiscovery = $field_discovery;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, $base_plugin_id) {
        return new static($base_plugin_id, $container->get('migrate_drupal.field_discovery'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        $vocabulary_source_plugin = static::getSourcePlugin('d7_taxonomy_vocabulary');
        try {
            $vocabulary_source_plugin->checkRequirements();
        } catch (RequirementsException $e) {
            // If the d7_taxonomy_vocabulary requirements failed, that means we do not
            // have a Drupal source database configured - there is nothing to
            // generate.
            return $this->derivatives;
        }
        try {
            foreach ($vocabulary_source_plugin as $row) {
                $bundle = $row->getSourceProperty('machine_name');
                $values = $base_plugin_definition;
                $values['label'] = $this->t('@label (@type)', [
                    '@label' => $values['label'],
                    '@type' => $row->getSourceProperty('name'),
                ]);
                $values['source']['bundle'] = $bundle;
                $values['destination']['default_bundle'] = $bundle;
                
                /** @var \Drupal\migrate\Plugin\MigrationInterface $migration */
                $migration = \Drupal::service('plugin.manager.migration')->createStubMigration($values);
                $this->fieldDiscovery
                    ->addBundleFieldProcesses($migration, 'taxonomy_term', $bundle);
                $this->derivatives[$bundle] = $migration->getPluginDefinition();
            }
        } catch (DatabaseExceptionWrapper $e) {
            // Once we begin iterating the source plugin it is possible that the
            // source tables will not exist. This can happen when the
            // MigrationPluginManager gathers up the migration definitions but we do
            // not actually have a Drupal 7 source database.
        }
        return $this->derivatives;
    }

}