MigrateMapDeleteEvent example

  public function delete(array $source_id_values, $messages_only = FALSE) {
    if (empty($source_id_values)) {
      throw new MigrateException('Without source identifier values it is impossible to find the row to delete.');
    }

    if (!$messages_only) {
      $map_query = $this->getDatabase()->delete($this->mapTableName());
      $map_query->condition($this::SOURCE_IDS_HASH, $this->getSourceIdsHash($source_id_values));
      // Notify anyone listening of the map row we're about to delete.       $this->eventDispatcher->dispatch(new MigrateMapDeleteEvent($this, $source_id_values), MigrateEvents::MAP_DELETE);
      $map_query->execute();
    }
    $message_query = $this->getDatabase()->delete($this->messageTableName());
    $message_query->condition($this::SOURCE_IDS_HASH, $this->getSourceIdsHash($source_id_values));
    $message_query->execute();
  }

  /** * {@inheritdoc} */
  public function deleteDestination(array $destination_id_values) {