SignalSlot Fiddle

Classes_Resource_ResourceStorageExtended.php

<?php

namespace STUBR\Template\Resource;

/**
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

class ResourceStorageExtended extends \TYPO3\CMS\Core\Resource\ResourceStorage {

  /**
   * Returns a string where any character not matching [.a-zA-Z0-9_-] is
   * substituted by '_'
   * Trailing dots are removed
   *
   * Previously in \TYPO3\CMS\Core\Utility\File\BasicFileUtility::cleanFileName()
   *
   * @param string $fileName Input string, typically the body of a fileName
   * @param string $charset Charset of the a fileName (defaults to current charset; depending on context)
   * @return string Output string with any characters not matching [.a-zA-Z0-9_-] is substituted by '_' and trailing dots removed
   * @throws Exception\InvalidFileNameException
   */
  public function sanitizeFileName($fileName, $charset = '')
  {
      // Handle UTF-8 characters
      if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['UTF8filesystem']) {
          // Allow ".", "-", 0-9, a-z, A-Z and everything beyond U+C0 (latin capital letter a with grave)
          $cleanFileName = preg_replace('/[' . self::UNSAFE_FILENAME_CHARACTER_EXPRESSION . ']/u', '_', trim($fileName));
      } else {
          // Define character set
          if (!$charset) {
              if (TYPO3_MODE === 'FE') {
                  $charset = $GLOBALS['TSFE']->renderCharset;
              } else {
                  // default for Backend
                  $charset = 'utf-8';
              }
          }
          // If a charset was found, convert fileName
          if ($charset) {
              $fileName = $this->getCharsetConversion()->specCharsToASCII($charset, $fileName);
          }
          // Replace unwanted characters by underscores
          $cleanFileName = preg_replace('/[' . self::UNSAFE_FILENAME_CHARACTER_EXPRESSION . '\\xC0-\\xFF]/', '_', trim($fileName));
      }
      // Strip trailing dots and return
      $cleanFileName = rtrim($cleanFileName, '.');
      if ($cleanFileName === '') {
          throw new Exception\InvalidFileNameException(
              'File name ' . $fileName . ' is invalid.',
              1320288991
          );
      }
      return $cleanFileName;
  }

}

?>

ext_localconf.php

<?php
/** @var \TYPO3\CMS\Extbase\SignalSlot\Dispatcher $signalSlotDispatcher */
$signalSlotDispatcher = \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\SignalSlot\Dispatcher::class);
$signalSlotDispatcher->connect(
  \TYPO3\CMS\Core\Resource\ResourceStorage::class,            // Signal class name
  'sanitizeFileName',                                         // Signal name
  \STUBR\Template\Resource\ResourceStorageExtended::class,        // Slot class name
  'sanitizeFileName',                                                 // Slot name
  false
);