file_requirements

file_requirements($phase)

function file_requirements($phase) {
  $requirements = array();

  // Check the server's ability to indicate upload progress.
  if ($phase == 'runtime') {
    $description = NULL;
    $implementation = file_progress_implementation();
    $server_software = \Drupal::request()->server->get('SERVER_SOFTWARE');

    // Test the web server identity.
    if (preg_match("/Nginx/i", $server_software)) {
      $is_nginx = TRUE;
      $is_apache = FALSE;
      $fastcgi = FALSE;
    }
    elseif (preg_match("/Apache/i", $server_software)) {
      $is_nginx = FALSE;
      $is_apache = TRUE;
      $fastcgi = strpos($server_software, 'mod_fastcgi') !== FALSE || strpos($server_software, 'mod_fcgi') !== FALSE;
    }
    else {
      $is_nginx = FALSE;
      $is_apache = FALSE;
      $fastcgi = FALSE;
    }

    if (!$is_apache && !$is_nginx) {
      $value = t('Not enabled');
      $description = t('Your server is not capable of displaying file upload progress. File upload progress requires an Apache server running PHP with mod_php or Nginx with PHP-FPM.');
    }
    elseif ($fastcgi) {
      $value = t('Not enabled');
      $description = t('Your server is not capable of displaying file upload progress. File upload progress requires PHP be run with mod_php or PHP-FPM and not as FastCGI.');
    }
    elseif (!$implementation && extension_loaded('apcu')) {
      $value = t('Not enabled');
      $description = t('Your server is capable of displaying file upload progress through APC, but it is not enabled. Add <code>apc.rfc1867 = 1</code> to your php.ini configuration. Alternatively, it is recommended to use <a href="http://pecl.php.net/package/uploadprogress">PECL uploadprogress</a>, which supports more than one simultaneous upload.');
    }
    elseif (!$implementation) {
      $value = t('Not enabled');
      $description = t('Your server is capable of displaying file upload progress, but does not have the required libraries. It is recommended to install the <a href="http://pecl.php.net/package/uploadprogress">PECL uploadprogress library</a> (preferred) or to install <a href="http://php.net/apcu">APC</a>.');
    }
    elseif ($implementation == 'apc') {
      $value = t('Enabled (<a href="http://php.net/manual/apcu.configuration.php#ini.apcu.rfc1867">APC RFC1867</a>)');
      $description = t('Your server is capable of displaying file upload progress using APC RFC1867. Note that only one upload at a time is supported. It is recommended to use the <a href="http://pecl.php.net/package/uploadprogress">PECL uploadprogress library</a> if possible.');
    }
    elseif ($implementation == 'uploadprogress') {
      $value = t('Enabled (<a href="http://pecl.php.net/package/uploadprogress">PECL uploadprogress</a>)');
    }
    $requirements['file_progress'] = array(
      'title' => t('Upload progress'),
      'value' => $value,
      'description' => $description,
    );
  }

  return $requirements;
}