public static function Unicode::mimeHeaderDecode in Plug 7

Decodes MIME/HTTP encoded header values.

Parameters

string $header: The header to decode.

Return value

string The mime-decoded header.

File

lib/Drupal/Component/Utility/Unicode.php, line 639

Contains \Drupal\Component\Utility\Unicode.

Class

Unicode

Provides Unicode-related conversions and operations.

Namespace

Drupal\Component\Utility

Code

public static function mimeHeaderDecode($header) {
  $callback = function ($matches) {
    $data = $matches[2] == 'B' ? base64_decode($matches[3]) : str_replace('_', ' ', quoted_printable_decode($matches[3]));
    if (strtolower($matches[1]) != 'utf-8') {
      $data = static::convertToUtf8($data, $matches[1]);
    }
    return $data;
  };

  // First step: encoded chunks followed by other encoded chunks (need to collapse whitespace)
  $header = preg_replace_callback('/=\\?([^?]+)\\?(Q|B)\\?([^?]+|\\?(?!=))\\?=\\s+(?==\\?)/', $callback, $header);

  // Second step: remaining chunks (do not collapse whitespace)
  return preg_replace_callback('/=\\?([^?]+)\\?(Q|B)\\?([^?]+|\\?(?!=))\\?=/', $callback, $header);
}