class FormatDate

class FormatDate extends ProcessPluginBase {

  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    if (empty($value) && $value !== '0' && $value !== 0) {
      return '';
    }

    // Validate the configuration.
    if (empty($this->configuration['from_format'])) {
      throw new MigrateException('Format date plugin is missing from_format configuration.');
    }
    if (empty($this->configuration['to_format'])) {
      throw new MigrateException('Format date plugin is missing to_format configuration.');
    }
    $fromFormat = $this->configuration['from_format'];
    $toFormat = $this->configuration['to_format'];
    $system_timezone = date_default_timezone_get();
    $default_timezone = !empty($system_timezone) ? $system_timezone : 'UTC';
    $from_timezone = $this->configuration['from_timezone'] ?? $default_timezone;
    $to_timezone = $this->configuration['to_timezone'] ?? $default_timezone;
    $settings = $this->configuration['settings'] ?? [];

    // Older versions of Drupal where omitting certain granularity values (also
    // known as "collected date attributes") resulted in invalid timestamps
    // getting stored.
    if ($fromFormat === 'Y-m-d\\TH:i:s') {
      $value = str_replace([
        '-00-00T',
        '-00T',
      ], [
        '-01-01T',
        '-01T',
      ], $value);
    }

    // Attempts to transform the supplied date using the defined input format.
    // DateTimePlus::createFromFormat can throw exceptions, so we need to
    // explicitly check for problems.
    try {
      $transformed = DateTimePlus::createFromFormat($fromFormat, $value, $from_timezone, $settings)
        ->format($toFormat, [
        'timezone' => $to_timezone,
      ]);
    } catch (\InvalidArgumentException $e) {
      throw new MigrateException(sprintf("Format date plugin could not transform '%s' using the format '%s'. Error: %s", $value, $fromFormat, $e
        ->getMessage()), $e
        ->getCode(), $e);
    } catch (\UnexpectedValueException $e) {
      throw new MigrateException(sprintf("Format date plugin could not transform '%s' using the format '%s'. Error: %s", $value, $fromFormat, $e
        ->getMessage()), $e
        ->getCode(), $e);
    }
    return $transformed;
  }

}