SqlContentEntityStorageSchema::onFieldStorageDefinitionDelete

public SqlContentEntityStorageSchema::onFieldStorageDefinitionDelete(FieldStorageDefinitionInterface $storage_definition)

public function onFieldStorageDefinitionDelete(FieldStorageDefinitionInterface $storage_definition) {
  // Only configurable fields currently support purging, so prevent deletion
  // of ones we can't purge if they have existing data.
  // @todo Add purging to all fields: https://www.drupal.org/node/2282119.
  try {
    if (!($storage_definition instanceof FieldStorageConfigInterface) && $this->storage->countFieldData($storage_definition, TRUE)) {
      throw new FieldStorageDefinitionUpdateForbiddenException('Unable to delete a field (' . $storage_definition->getName() . ' in ' . $storage_definition->getTargetEntityTypeId() . ' entity) with data that cannot be purged.');
    }
  }
  catch (DatabaseException $e) {
    // This may happen when changing field storage schema, since we are not
    // able to use a table mapping matching the passed storage definition.
    // @todo Revisit this once we are able to instantiate the table mapping
    //   properly. See https://www.drupal.org/node/2274017.
    return;
  }

  // Retrieve a table mapping which contains the deleted field still.
  $table_mapping = $this->storage->getTableMapping(
  $this->entityManager->getLastInstalledFieldStorageDefinitions($this->entityType->id())
  );
  if ($table_mapping->requiresDedicatedTableStorage($storage_definition)) {
    // Move the table to a unique name while the table contents are being
    // deleted.
    $table = $table_mapping->getDedicatedDataTableName($storage_definition);
    $new_table = $table_mapping->getDedicatedDataTableName($storage_definition, TRUE);
    $this->database->schema()->renameTable($table, $new_table);
    if ($this->entityType->isRevisionable()) {
      $revision_table = $table_mapping->getDedicatedRevisionTableName($storage_definition);
      $revision_new_table = $table_mapping->getDedicatedRevisionTableName($storage_definition, TRUE);
      $this->database->schema()->renameTable($revision_table, $revision_new_table);
    }
  }

  // @todo Remove when finalizePurge() is invoked from the outside for all
  //   fields: https://www.drupal.org/node/2282119.
  if (!($storage_definition instanceof FieldStorageConfigInterface)) {
    $this->performFieldSchemaOperation('delete', $storage_definition);
  }
}