/**
* {@inheritdoc}
*/
public function rollback()
{
// Only begin the rollback operation if the migration is currently idle.
if ($this->migration->getStatus() !== MigrationInterface::STATUS_IDLE) {
$this->message->display($this->t('Migration @id is busy with another operation: @status', ['@id' => $this->migration->id(), '@status' => $this->t($this->migration->getStatusLabel())]), 'error');
return MigrationInterface::RESULT_FAILED;
}
// Announce that rollback is about to happen.
$this->getEventDispatcher()->dispatch(MigrateEvents::PRE_ROLLBACK, new MigrateRollbackEvent($this->migration));
// Optimistically assume things are going to work out; if not, $return will be
// updated to some other status.
$return = MigrationInterface::RESULT_COMPLETED;
$this->migration->setStatus(MigrationInterface::STATUS_ROLLING_BACK);
$id_map = $this->migration->getIdMap();
$destination = $this->migration->getDestinationPlugin();
// Loop through each row in the map, and try to roll it back.
foreach ($id_map as $map_row) {
$destination_key = $id_map->currentDestination();
if ($destination_key) {
$map_row = $id_map->getRowByDestination($destination_key);
if ($map_row['rollback_action'] == MigrateIdMapInterface::ROLLBACK_DELETE) {
$this->getEventDispatcher()->dispatch(MigrateEvents::PRE_ROW_DELETE, new MigrateRowDeleteEvent($this->migration, $destination_key));
$destination->rollback($destination_key);
$this->getEventDispatcher()->dispatch(MigrateEvents::POST_ROW_DELETE, new MigrateRowDeleteEvent($this->migration, $destination_key));
}
// We're now done with this row, so remove it from the map.
$id_map->deleteDestination($destination_key);
}
// Check for memory exhaustion.
if (($return = $this->checkStatus()) != MigrationInterface::RESULT_COMPLETED) {
break;
}
// If anyone has requested we stop, return the requested result.
if ($this->migration->getStatus() == MigrationInterface::STATUS_STOPPING) {
$return = $this->migration->getInterruptionResult();
$this->migration->clearInterruptionResult();
break;
}
}
// If rollback completed successfully, reset the high water mark.
if ($return == MigrationInterface::RESULT_COMPLETED) {
$this->migration->saveHighWater(NULL);
}
// Notify modules that rollback attempt was complete.
$this->getEventDispatcher()->dispatch(MigrateEvents::POST_ROLLBACK, new MigrateRollbackEvent($this->migration));
$this->migration->setStatus(MigrationInterface::STATUS_IDLE);
return $return;
}