function _filter_xss_split

Processes an HTML tag.

Parameters

@m: An array with various meaning depending on the value of $store. If $store is TRUE then the array contains the allowed tags. If $store is FALSE then the array has one element, the HTML tag to process.

$store: Whether to store $m.

Return value

If the element isn't allowed, an empty string. Otherwise, the cleaned up version of the HTML element.

File

modules/filter.module, line 1180

Framework for handling filtering of content.

Code

function _filter_xss_split($m, $store = FALSE) {
  static $allowed_html;
  if ($store) {
    $allowed_html = array_flip($m);
    return;
  }
  $string = $m[1];
  if (substr($string, 0, 1) != '<') {

    // We matched a lone ">" character
    return '&gt;';
  }
  if (!preg_match('%^<\\s*(/\\s*)?([a-zA-Z0-9]+)([^>]*)>?$%', $string, $matches)) {

    // Seriously malformed
    return '';
  }
  $slash = trim($matches[1]);
  $elem =& $matches[2];
  $attrlist =& $matches[3];
  if (!isset($allowed_html[strtolower($elem)])) {

    // Disallowed HTML element
    return '';
  }
  if ($slash != '') {
    return "</{$elem}>";
  }

  // Is there a closing XHTML slash at the end of the attributes?
  // In PHP 5.1.0+ we could count the changes, currently we need a separate match
  $xhtml_slash = preg_match('%\\s?/\\s*$%', $attrlist) ? ' /' : '';
  $attrlist = preg_replace('%(\\s?)/\\s*$%', '\\1', $attrlist);

  // Clean up attributes
  $attr2 = implode(' ', _filter_xss_attributes($attrlist));
  $attr2 = preg_replace('/[<>]/', '', $attr2);
  $attr2 = strlen($attr2) ? ' ' . $attr2 : '';
  return "<{$elem}{$attr2}{$xhtml_slash}>";
}