function mailsystem_html_to_text in Mail System 7.2

Same name and namespace in other branches

1. 8.2 html_to_text.inc \mailsystem_html_to_text()
2. 6.2 html_to_text.inc \mailsystem_html_to_text()
3. 7.3 html_to_text.inc \mailsystem_html_to_text()

Transform an HTML string into plain text, preserving the structure of the markup. Useful for preparing the body of a node to be sent by e-mail.

The output will be suitable for use as 'format=flowed; delsp=yes' text (RFC 3676) and can be passed directly to drupal_mail() for sending.

We deliberately use variable_get('mail_line_endings', MAIL_LINE_ENDINGS) rather than "\r\n".

This function provides suitable alternatives for the following tags:

<a> <address> <b> <blockquote> <br /> <caption> <cite> <dd> <div> <dl> <dt> <em> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <ol> <p> <pre> <strong> <table> <tbody> <td> <tfoot> <thead> <tr> <u> <ul>

The following tag attributes are supported:

• <a href=...>: Hyperlink destination urls.
• <li value=...>: Ordered list item numbers.
• <ol start=...>: Ordered list start number.

Parameters

$string: The string to be transformed.

$allowed_tags: (optional) If supplied, a list of tags that will be transformed. If omitted, all supported tags are transformed.

Return value

The transformed string.

See also

drupal_mail()

1 string reference to 'mailsystem_html_to_text'

mailsystem_init in ./mailsystem.module

Implements hook_init().

File

./html_to_text.inc, line 103

Copy of drupal_html_to_text improvements from issue #299138.

Code

function mailsystem_html_to_text($string, $allowed_tags = NULL) {
  $eol = variable_get('mail_line_endings', MAIL_LINE_ENDINGS);

  // Cache list of supported tags.
  static $supported_tags;
  if (!isset($supported_tags)) {
    $supported_tags = array(
      'a',
      'address',
      'b',
      'blockquote',
      'br',
      'cite',
      'dd',
      'div',
      'dl',
      'dt',
      'em',
      'h1',
      'h2',
      'h3',
      'h4',
      'h5',
      'h6',
      'hr',
      'i',
      'li',
      'ol',
      'p',
      'pre',
      'strong',
      'table',
      'td',
      'tr',
      'u',
      'ul',
    );
  }

  // Make sure only supported tags are kept.
  $allowed_tags = isset($allowed_tags) ? array_intersect($supported_tags, $allowed_tags) : $supported_tags;

  // Parse $string into a DOM tree.
  $dom = filter_dom_load($string);
  $notes = array();

  // Recursively convert the DOM tree into plain text.
  $text = _mailsystem_html_to_text($dom->documentElement, $allowed_tags, $notes);

  // Hard-wrap at 1000 characters (including the line break sequence)
  // and space-stuff special lines.
  $text = mailsystem_wrap_mail($text, array(
    'max' => 1000 - strlen($eol),
    'hard' => TRUE,
  ));

  // Change non-breaking spaces back to regular spaces, and trim line breaks.
  // chr(160) is the non-breaking space character.
  $text = str_replace(chr(160), ' ', trim($text, $eol));

  // Add footnotes;
  if ($notes) {

    // Add a blank line before the footnote list.
    $text .= $eol;
    foreach ($notes as $url => $note) {
      $text .= $eol . '[' . $note . '] ' . $url;
    }
  }
  return $text;
}