field_entity_bundle_delete

field_entity_bundle_delete($entity_type_id, $bundle)

function field_entity_bundle_delete($entity_type_id, $bundle) {
  $storage = \Drupal::entityManager()->getStorage('field_config');
  // Get the fields on the bundle.
  $fields = $storage->loadByProperties(['entity_type' => $entity_type_id, 'bundle' => $bundle]);
  // This deletes the data for the field as well as the field themselves. This
  // function actually just marks the data and fields as deleted, leaving the
  // garbage collection for a separate process, because it is not always
  // possible to delete this much data in a single page request (particularly
  // since for some field types, the deletion is more than just a simple DELETE
  // query).
  foreach ($fields as $field) {
    $field->delete();
  }

  // We are duplicating the work done by
  // \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::onDependencyRemoval()
  // because we need to take into account bundles that are not provided by a
  // config entity type so they are not part of the config dependencies.

  // Gather a list of all entity reference fields.
  $map = \Drupal::entityManager()->getFieldMapByFieldType('entity_reference');
  $ids = [];
  foreach ($map as $type => $info) {
    foreach ($info as $name => $data) {
      foreach ($data['bundles'] as $bundle_name) {
        $ids[] = "$type.$bundle_name.$name";
      }
    }
  }

  // Update the 'target_bundles' handler setting if needed.
  foreach (FieldConfig::loadMultiple($ids) as $field_config) {
    if ($field_config->getSetting('target_type') == $entity_type_id) {
      $handler_settings = $field_config->getSetting('handler_settings');
      if (isset($handler_settings['target_bundles'][$bundle])) {
        unset($handler_settings['target_bundles'][$bundle]);
        $field_config->setSetting('handler_settings', $handler_settings);
        $field_config->save();

        // In case we deleted the only target bundle allowed by the field we
        // have to log a critical message because the field will not function
        // correctly anymore.
        if ($handler_settings['target_bundles'] === []) {
          \Drupal::logger('entity_reference')->critical('The %target_bundle bundle (entity type: %target_entity_type) was deleted. As a result, the %field_name entity reference field (entity_type: %entity_type, bundle: %bundle) no longer has any valid bundle it can reference. The field is not working correctly anymore and has to be adjusted.', [
            '%target_bundle' => $bundle,
            '%target_entity_type' => $entity_type_id,
            '%field_name' => $field_config->getName(),
            '%entity_type' => $field_config->getTargetEntityTypeId(),
            '%bundle' => $field_config->getTargetBundle()
          ]);
        }
      }
    }
  }
}