Compress file with ArchiveInterface without file paths

Question

I'm trying to create an archive of log files to be downloadable in a form making a custom module in Drupal 9. In the form, the user can change the format of the archive, as per image:

Here below my code:

private function download($form, $form_state) {
  $format = $form_state->getValue('format');
  $folder = $form_state->getValue('folders');

  $date = new DateTime();
  $date = $date->format("y_m_d_H_i_s");

  $logsDirectory = \Drupal::service('file_system')
    ->realpath($folder . "://logs/");
  //Retrieve all the files in the folder.
  $logs = glob($logsDirectory . "/*.log");

  $archiveName = $date . $format;

  $archive_path = \Drupal::service('file_system')
    ->saveData('', 'temporary://' . $archiveName);
  $archive = \Drupal::service('plugin.manager.archiver')
    ->getInstance(['filepath' => $archive_path]);

  foreach ($logs as $log) {
    $archive->add($log);
  }

  $response = new BinaryFileResponse($archive_path);
  $response->headers->set('Content-type', $this->getContentTypes($format));
  $response->headers->set('Content-Disposition', 'attachment;filename="' . $archive_path . '"');
  $form_state->setResponse($response);
}

Everything is going fine, I managed to achieve a button in this way that, when pressed, downloads the archive with all the log files inside. The problem is that inside of this zip all the files are inside their absolute path, in this way:

This is because in the ArchiveInterface Class the add method only accepts one parameter, $file_path, and it is not supported to add a second parameter to specify the name of the files. How could I solve this problem, being able of adding inside the archive only the files and not all the subfolders?

Answer 1

Drupal's Zip archiver doesn't support that functionality directly, but the underlying PHP ZipArchive it uses does (see ZipArchive::addFile()), and you can get a reference to that object from the Drupal archiver.

For example:

$zip_archive = $archive->getArchive();
foreach ($logs as $log) {
  $zip_archive->addFile($log, basename($log));
}

Bear in mind that this only works well for a glob that brings back unique file names every time. If the structure changes and you end up with subfolders containing files with name clashes, you'll need to update the loop to accommodate, or risk some files not being included.