function drupal_mail_format_display_name in Drupal 7

Return a RFC-2822 compliant "display-name" component.

The "display-name" component is used in mail header "Originator" fields (From, Sender, Reply-to) to give a human-friendly description of the address, i.e. From: My Display Name <xyz@example.org>. RFC-822 and RFC-2822 define its syntax and rules. This method gets as input a string to be used as "display-name" and formats it to be RFC compliant.

Parameters

string $string: A string to be used as "display-name".

Return value

string A RFC compliant version of the string, ready to be used as "display-name" in mail originator header fields.

1 call to drupal_mail_format_display_name()

drupal_mail in includes/mail.inc

Composes and optionally sends an e-mail message.

File

includes/mail.inc, line 587

API functions for processing and sending e-mail.

Code

function drupal_mail_format_display_name($string) {

  // Make sure we don't process html-encoded characters. They may create
  // unneeded trouble if left encoded, besides they will be correctly
  // processed if decoded.
  $string = decode_entities($string);

  // If string contains non-ASCII characters it must be (short) encoded
  // according to RFC-2047. The output of a "B" (Base64) encoded-word is
  // always safe to be used as display-name.
  $safe_display_name = mime_header_encode($string, TRUE);

  // Encoded-words are always safe to be used as display-name because don't
  // contain any RFC 2822 "specials" characters. However
  // mimeHeaderEncode() encodes a string only if it contains any
  // non-ASCII characters, and leaves its value untouched (un-encoded) if
  // ASCII only. For this reason in order to produce a valid display-name we
  // still need to make sure there are no "specials" characters left.
  if (preg_match('/[' . preg_quote(MAIL_RFC_2822_SPECIALS) . ']/', $safe_display_name)) {

    // If string is already quoted, it may or may not be escaped properly, so
    // don't trust it and reset.
    if (preg_match('/^"(.+)"$/', $safe_display_name, $matches)) {
      $safe_display_name = str_replace(array(
        '\\\\',
        '\\"',
      ), array(
        '\\',
        '"',
      ), $matches[1]);
    }

    // Transform the string in a RFC-2822 "quoted-string" by wrapping it in
    // double-quotes. Also make sure '"' and '\' occurrences are escaped.
    $safe_display_name = '"' . str_replace(array(
      '\\',
      '"',
    ), array(
      '\\\\',
      '\\"',
    ), $safe_display_name) . '"';
  }
  return $safe_display_name;
}