4 * Validates contents based on NMTOKENS attribute type.
6 class HTMLPurifier_AttrDef_HTML_Nmtokens extends HTMLPurifier_AttrDef
9 public function validate($string, $config, $context) {
11 $string = trim($string);
13 // early abort: '' and '0' (strings that convert to false) are invalid
14 if (!$string) return false;
16 $tokens = $this->split($string, $config, $context);
17 $tokens = $this->filter($tokens, $config, $context);
18 if (empty($tokens)) return false;
19 return implode(' ', $tokens);
24 * Splits a space separated list of tokens into its constituent parts.
26 protected function split($string, $config, $context) {
28 // do the preg_match, capture all subpatterns for reformulation
30 // we don't support U+00A1 and up codepoints or
31 // escaping because I don't know how to do that with regexps
32 // and plus it would complicate optimization efforts (you never
34 $pattern = '/(?:(?<=\s)|\A)'. // look behind for space or string start
35 '((?:--|-?[A-Za-z_])[A-Za-z_\-0-9]*)'.
36 '(?:(?=\s)|\z)/'; // look ahead for space or string end
37 preg_match_all($pattern, $string, $matches);
42 * Template method for removing certain tokens based on arbitrary criteria.
43 * @note If we wanted to be really functional, we'd do an array_filter
44 * with a callback. But... we're not.
46 protected function filter($tokens, $config, $context) {