class TemporaryStream

class TemporaryStream extends LocalStream {
    
    /**
     * {@inheritdoc}
     */
    public static function getType() {
        return StreamWrapperInterface::LOCAL_HIDDEN;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getName() {
        return t('Temporary files');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDescription() {
        return t('Temporary local files for upload and previews.');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDirectoryPath() {
        return \Drupal::service('file_system')->getTempDirectory();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getExternalUrl() {
        $path = str_replace('\\', '/', $this->getTarget());
        return Url::fromRoute('system.temporary', [], [
            'absolute' => TRUE,
            'query' => [
                'file' => $path,
            ],
        ])->toString();
    }

}