class SkipOnEmpty

class SkipOnEmpty extends ProcessPluginBase {

  /**
   * Skips the current row when value is not set.
   *
   * @param mixed $value
   *   The input value.
   * @param \Drupal\migrate\MigrateExecutableInterface $migrate_executable
   *   The migration in which this process is being executed.
   * @param \Drupal\migrate\Row $row
   *   The row from the source to process.
   * @param string $destination_property
   *   The destination property currently worked on. This is only used together
   *   with the $row above.
   *
   * @return mixed
   *   The input value, $value, if it is not empty.
   *
   * @throws \Drupal\migrate\MigrateSkipRowException
   *   Thrown if the source property is not set and the row should be skipped,
   *   records with STATUS_IGNORED status in the map.
   */
  public function row($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    if (!$value) {
      $message = !empty($this->configuration['message']) ? $this->configuration['message'] : '';
      throw new MigrateSkipRowException($message);
    }
    return $value;
  }

  /**
   * Stops processing the current property when value is not set.
   *
   * @param mixed $value
   *   The input value.
   * @param \Drupal\migrate\MigrateExecutableInterface $migrate_executable
   *   The migration in which this process is being executed.
   * @param \Drupal\migrate\Row $row
   *   The row from the source to process.
   * @param string $destination_property
   *   The destination property currently worked on. This is only used together
   *   with the $row above.
   *
   * @return mixed
   *   The input value, $value, if it is not empty.
   */
  public function process($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    if (!$value) {
      $this
        ->stopPipeline();
      return NULL;
    }
    return $value;
  }

}