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     /**
  10      * @param string $string
  11      * @param HTMLPurifier_Config $config
  12      * @param HTMLPurifier_Context $context
  13      * @return bool|string
  14      */
  15     public function validate($string, $config, $context)
  16     {
  17         $string = trim($string);
  18
  19         // early abort: '' and '0' (strings that convert to false) are invalid
  20         if (!$string) {
  21             return false;
  22         }
  23
  24         $tokens = $this->split($string, $config, $context);
  25         $tokens = $this->filter($tokens, $config, $context);
  26         if (empty($tokens)) {
  27             return false;
  28         }
  29         return implode(' ', $tokens);
  30     }
  31
  32     /**
  33      * Splits a space separated list of tokens into its constituent parts.
  34      * @param string $string
  35      * @param HTMLPurifier_Config $config
  36      * @param HTMLPurifier_Context $context
  37      * @return array
  38      */
  39     protected function split($string, $config, $context)
  40     {
  41         // OPTIMIZABLE!
  42         // do the preg_match, capture all subpatterns for reformulation
  43
  44         // we don't support U+00A1 and up codepoints or
  45         // escaping because I don't know how to do that with regexps
  46         // and plus it would complicate optimization efforts (you never
  47         // see that anyway).
  48         $pattern = '/(?:(?<=\s)|\A)' . // look behind for space or string start
  49             '((?:--|-?[A-Za-z_])[A-Za-z_\-0-9]*)' .
  50             '(?:(?=\s)|\z)/'; // look ahead for space or string end
  51         preg_match_all($pattern, $string, $matches);
  52         return $matches[1];
  53     }
  54
  55     /**
  56      * Template method for removing certain tokens based on arbitrary criteria.
  57      * @note If we wanted to be really functional, we'd do an array_filter
  58      *       with a callback. But... we're not.
  59      * @param array $tokens
  60      * @param HTMLPurifier_Config $config
  61      * @param HTMLPurifier_Context $context
  62      * @return array
  63      */
  64     protected function filter($tokens, $config, $context)
  65     {
  66         return $tokens;
  67     }
  68 }
  69
  70 // vim: et sw=4 sts=4