Performs format=flowed soft wrapping for mail (RFC 3676).

We use delsp=yes wrapping, but only break non-spaced languages when absolutely necessary to avoid compatibility issues.

We deliberately use LF rather than CRLF, see drupal_mail().

Parameters

string $text: The plain text to process.

string $indent (optional): A string to indent the text with. Only '>' characters are repeated on subsequent wrapped lines. Others are replaced by spaces.

Return value

string The content of the email as a string with formatting applied.

File

drupal-7.x/includes/mail.inc, line 351

API functions for processing and sending e-mail.

Code

function drupal_wrap_mail($text, $indent = '') {
  // Convert CRLF into LF.
  $text = str_replace("\r", '', $text);
  // See if soft-wrapping is allowed.
  $clean_indent = _drupal_html_to_text_clean($indent);
  $soft = strpos($clean_indent, ' ') === FALSE;
  // Check if the string has line breaks.
  if (strpos($text, "\n") !== FALSE) {
    // Remove trailing spaces to make existing breaks hard, but leave signature
    // marker untouched (RFC 3676, Section 4.3).
    $text = preg_replace('/(?(?<!^--) +\n|  +\n)/m', "\n", $text);
    // Wrap each line at the needed width.
    $lines = explode("\n", $text);
    array_walk($lines, '_drupal_wrap_mail_line', array('soft' => $soft, 'length' => strlen($indent)));
    $text = implode("\n", $lines);
  }
  else {
    // Wrap this line.
    _drupal_wrap_mail_line($text, 0, array('soft' => $soft, 'length' => strlen($indent)));
  }
  // Empty lines with nothing but spaces.
  $text = preg_replace('/^ +\n/m', "\n", $text);
  // Space-stuff special lines.
  $text = preg_replace('/^(>| |From)/m', ' $1', $text);
  // Apply indentation. We only include non-'>' indentation on the first line.
  $text = $indent . substr(preg_replace('/^/m', $clean_indent, $text), strlen($indent));

  return $text;
}