TYPO3 isDir, getRealPath don't work on the Controller - php

Question

What i would like to do, is to zip my fileadmin and my extension folder with a zipAction on my controller. So i took a piece of code from here
and i have this:
$fileAdminPath = 'fileadmin';
$archiveName = $importerSettings['fileadminArchiveName'];
$zip = new \ZipArchive;
$zip->open($archiveName, \ZipArchive::CREATE | \ZipArchive::OVERWRITE);
$files = new \RecursiveIteratorIterator (new \RecursiveDirectoryIterator($fileAdminPath), \RecursiveIteratorIterator::LEAVES_ONLY);
if (!$file->isDir()) {
// Get real and relative path for current file
$filePath = $file->getRealPath();
$relativePath = substr($filePath, strlen($fileAdminPath) + 1);
// Add current file to archive
$zip->addFile($filePath, $relativePath);
}
// Zip archive will be created only after closing object
$zip->close();
Now, when the code reaches the isDir() part, i get the following error:
Call to a member function isDir() on null
If i remove it and let the code run again, the getRealPath() gets the same error. So i am guessing i missing a namespace or something like that, that stores these functions.
On a local php file (index.php) and MAMPP it works. On TYPO3, not.
By the way, i am not sure if the controller really reads the fileadmin path. If i got it wrong, please feel free to correct me.
Best regards

Answer 1

If you run your script inside an extension, this script is searching fileadmin within your extension directory.
Try to use the following script:
$fileAdminPath = \TYPO3\CMS\Core\Utility\GeneralUtility::getFileAbsFileName('fileadmin');
Edit:
You should also walk the files in an foreach because you scan an directory recursiv:
foreach ($files as $file) {
if (!$file->isDir()) {
// Get real and relative path for current file
$filePath = $file->getRealPath();
$relativePath = substr($filePath, strlen($fileAdminPath) + 1);
// Add current file to archive
$zip->addFile($filePath, $relativePath);
}
}