lib/htmlpurifier/library/HTMLPurifier/AttrDef/HTML/Nmtokens.php

   1 <?php
   2
   3 /**
   4  * Validates contents based on NMTOKENS attribute type.
   5  */
   6 class HTMLPurifier_AttrDef_HTML_Nmtokens extends HTMLPurifier_AttrDef
   7 {
   8
   9     public function validate($string, $config, $context) {
  10
  11         $string = trim($string);
  12
  13         // early abort: '' and '0' (strings that convert to false) are invalid
  14         if (!$string) return false;
  15
  16         $tokens = $this->split($string, $config, $context);
  17         $tokens = $this->filter($tokens, $config, $context);
  18         if (empty($tokens)) return false;
  19         return implode(' ', $tokens);
  20
  21     }
  22
  23     /**
  24      * Splits a space separated list of tokens into its constituent parts.
  25      */
  26     protected function split($string, $config, $context) {
  27         // OPTIMIZABLE!
  28         // do the preg_match, capture all subpatterns for reformulation
  29
  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
  33         // see that anyway).
  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);
  38         return $matches[1];
  39     }
  40
  41     /**
  42      * Template method for removing certain tokens based on arbitrary criteria.
  43      * @note If we wanted to be really functional, we'd do an array_filter
  44      *       with a callback. But... we're not.
  45      */
  46     protected function filter($tokens, $config, $context) {
  47         return $tokens;
  48     }
  49
  50 }
  51
  52 // vim: et sw=4 sts=4