delete() has a complete entity to pass to the various deletion * steps, the Field API purge process only has the field data it has previously * stored. It cannot reconstruct complete original entities to pass to the * deletion operations. It is even possible that the original entity to which * some Field API data was attached has been itself deleted before the field * purge operation takes place. * * Field API resolves this problem by using stub entities during purge * operations, containing only the information from the original entity that * Field API knows about: entity type, ID, revision ID, and bundle. It also * contains the field data for whichever field is currently being purged. * * See @link field Field API @endlink for information about the other parts of * the Field API. */ /** * Purges a batch of deleted Field API data, field storages, or fields. * * This function will purge deleted field data in batches. The batch size * is defined as an argument to the function, and once each batch is finished, * it continues with the next batch until all have completed. If a deleted field * with no remaining data records is found, the field itself will * be purged. If a deleted field storage with no remaining fields is found, the * field storage itself will be purged. * * @param int $batch_size * The maximum number of field data records to purge before returning. * @param string $field_storage_unique_id * (optional) Limit the purge to a specific field storage. Defaults to NULL. */ function field_purge_batch($batch_size, $field_storage_unique_id = NULL) { /** @var \Drupal\Core\Field\DeletedFieldsRepositoryInterface $deleted_fields_repository */ $deleted_fields_repository = \Drupal::service('entity_field.deleted_fields_repository'); $fields = $deleted_fields_repository->getFieldDefinitions($field_storage_unique_id); $info = \Drupal::entityTypeManager()->getDefinitions(); foreach ($fields as $field) { $entity_type = $field->getTargetEntityTypeId(); // We cannot purge anything if the entity type is unknown (e.g. the // providing module was uninstalled). // @todo Revisit after https://www.drupal.org/node/2080823. if (!isset($info[$entity_type])) { \Drupal::logger('field')->warning("Cannot remove field @field_name because the entity type is unknown: %entity_type", ['@field_name' => $field->getName(), '%entity_type' => $entity_type]); continue; } $count_purged = \Drupal::entityTypeManager()->getStorage($entity_type)->purgeFieldData($field, $batch_size); if ($count_purged < $batch_size || $count_purged == 0) { // No field data remains for the field, so we can remove it. field_purge_field($field); } $batch_size -= $count_purged; // Only delete up to the maximum number of records. if ($batch_size == 0) { break; } } // Retrieve all deleted field storages. Any that have no fields can be purged. foreach ($deleted_fields_repository->getFieldStorageDefinitions() as $field_storage) { if ($field_storage_unique_id && $field_storage->getUniqueStorageIdentifier() != $field_storage_unique_id) { // If a specific UUID is provided, only purge the corresponding field. continue; } // We cannot purge anything if the entity type is unknown (e.g. the // providing module was uninstalled). // @todo Revisit after https://www.drupal.org/node/2080823. if (!isset($info[$field_storage->getTargetEntityTypeId()])) { continue; } $fields = $deleted_fields_repository->getFieldDefinitions($field_storage->getUniqueStorageIdentifier()); if (empty($fields)) { field_purge_field_storage($field_storage); } } } /** * Purges a field record from the database. * * This function assumes all data for the field has already been purged and * should only be called by field_purge_batch(). * * @param \Drupal\Core\Field\FieldDefinitionInterface $field * The field to purge. */ function field_purge_field(FieldDefinitionInterface $field) { /** @var \Drupal\Core\Field\DeletedFieldsRepositoryInterface $deleted_fields_repository */ $deleted_fields_repository = \Drupal::service('entity_field.deleted_fields_repository'); $deleted_fields_repository->removeFieldDefinition($field); // Invoke external hooks after the cache is cleared for API consistency. \Drupal::moduleHandler()->invokeAll('field_purge_field', [$field]); } /** * Purges a field record from the database. * * This function assumes all fields for the field storage has already been * purged, and should only be called by field_purge_batch(). * * @param \Drupal\Core\Field\FieldStorageDefinitionInterface $field_storage * The field storage to purge. * * @throws \Drupal\Core\Field\FieldException */ function field_purge_field_storage(FieldStorageDefinitionInterface $field_storage) { /** @var \Drupal\Core\Field\DeletedFieldsRepositoryInterface $deleted_fields_repository */ $deleted_fields_repository = \Drupal::service('entity_field.deleted_fields_repository'); $fields = $deleted_fields_repository->getFieldDefinitions($field_storage->getUniqueStorageIdentifier()); if (count($fields) > 0) { throw new FieldException("Attempt to purge a field storage '{$field_storage->getName()}' that still has fields."); } $deleted_fields_repository->removeFieldStorageDefinition($field_storage); // Notify the storage layer. \Drupal::entityTypeManager()->getStorage($field_storage->getTargetEntityTypeId())->finalizePurge($field_storage); // Invoke external hooks after the cache is cleared for API consistency. \Drupal::moduleHandler()->invokeAll('field_purge_field_storage', [$field_storage]); } /** * @} End of "defgroup field_purge". */