class TableSortExtender

class TableSortExtender extends SelectExtender {
  
  /**
   * {@inheritdoc}
   */
  public function __construct(SelectInterface $query, Connection $connection) {
    parent::__construct($query, $connection);
    // Add convenience tag to mark that this is an extended query. We have to
    // do this in the constructor to ensure that it is set before preExecute()
    // gets called.
    $this->addTag('tablesort');
  }
  
  /**
   * Order the query based on a header array.
   *
   * @param array $header
   *   Table header array.
   *
   * @return \Drupal\Core\Database\Query\SelectInterface
   *   The called object.
   *
   * @see table.html.twig
   */
  public function orderByHeader(array $header) {
    $context = TableSort::getContextFromRequest($header, \Drupal::request());
    if (!empty($context['sql'])) {
      // Based on code from \Drupal\Core\Database\Connection::escapeTable(),
      // but this can also contain a dot.
      $field = preg_replace('/[^A-Za-z0-9_.]+/', '', $context['sql']);
      // orderBy() will ensure that only ASC/DESC values are accepted, so we
      // don't need to sanitize that here.
      $this->orderBy($field, $context['sort']);
    }
    return $this;
  }

}