Replaces invalid UTF-8 byte sequences in a string.

PHP's mb_convert_encoding() replaces every invalid byte with a ? so any that already present are preserved when a different $unknown_character is specified.

Parameters

string $string: The string to coerce to valid UTF-8.

string $unknown_character: The character substituted for invalid byte sequences.

Return value

string The string as valid UTF-8.

File

core/modules/file/src/EventSubscriber/FileEventSubscriber.php, line 150

Class

FileEventSubscriber

Sanitizes uploaded filenames.

Namespace

Drupal\file\EventSubscriber

Code

private static function coerceToValidUtf8(string $string, string $unknown_character = '?') : string {
  $code_point = mb_ord($unknown_character, 'UTF-8');
  if ($code_point === FALSE) {
    throw new \InvalidArgumentException('$unknown_character must be a single valid UTF-8 character.');
  }
  $previous = mb_substitute_character();
  mb_substitute_character($code_point);
  $string = mb_convert_encoding($string, 'UTF-8', 'UTF-8');
  mb_substitute_character($previous);
  return $string;
}

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