library/HTMLPurifier/AttrDef/HTML/ID.php

   1 <?php
   2
   3 /**
   4  * Validates the HTML attribute ID.
   5  * @warning Even though this is the id processor, it
   6  *          will ignore the directive Attr:IDBlacklist, since it will only
   7  *          go according to the ID accumulator. Since the accumulator is
   8  *          automatically generated, it will have already absorbed the
   9  *          blacklist. If you're hacking around, make sure you use load()!
  10  */
  11
  12 class HTMLPurifier_AttrDef_HTML_ID extends HTMLPurifier_AttrDef
  13 {
  14
  15     // selector is NOT a valid thing to use for IDREFs, because IDREFs
  16     // *must* target IDs that exist, whereas selector #ids do not.
  17
  18     /**
  19      * Determines whether or not we're validating an ID in a CSS
  20      * selector context.
  21      * @type bool
  22      */
  23     protected $selector;
  24
  25     /**
  26      * @param bool $selector
  27      */
  28     public function __construct($selector = false)
  29     {
  30         $this->selector = $selector;
  31     }
  32
  33     /**
  34      * @param string $id
  35      * @param HTMLPurifier_Config $config
  36      * @param HTMLPurifier_Context $context
  37      * @return bool|string
  38      */
  39     public function validate($id, $config, $context)
  40     {
  41         if (!$this->selector && !$config->get('Attr.EnableID')) {
  42             return false;
  43         }
  44
  45         $id = trim($id); // trim it first
  46
  47         if ($id === '') {
  48             return false;
  49         }
  50
  51         $prefix = $config->get('Attr.IDPrefix');
  52         if ($prefix !== '') {
  53             $prefix .= $config->get('Attr.IDPrefixLocal');
  54             // prevent re-appending the prefix
  55             if (strpos($id, $prefix) !== 0) {
  56                 $id = $prefix . $id;
  57             }
  58         } elseif ($config->get('Attr.IDPrefixLocal') !== '') {
  59             trigger_error(
  60                 '%Attr.IDPrefixLocal cannot be used unless ' .
  61                 '%Attr.IDPrefix is set',
  62                 E_USER_WARNING
  63             );
  64         }
  65
  66         if (!$this->selector) {
  67             $id_accumulator =& $context->get('IDAccumulator');
  68             if (isset($id_accumulator->ids[$id])) {
  69                 return false;
  70             }
  71         }
  72
  73         // we purposely avoid using regex, hopefully this is faster
  74
  75         if (ctype_alpha($id)) {
  76             $result = true;
  77         } else {
  78             if (!ctype_alpha(@$id[0])) {
  79                 return false;
  80             }
  81             // primitive style of regexps, I suppose
  82             $trim = trim(
  83                 $id,
  84                 'A..Za..z0..9:-._'
  85             );
  86             $result = ($trim === '');
  87         }
  88
  89         $regexp = $config->get('Attr.IDBlacklistRegexp');
  90         if ($regexp && preg_match($regexp, $id)) {
  91             return false;
  92         }
  93
  94         if (!$this->selector && $result) {
  95             $id_accumulator->add($id);
  96         }
  97
  98         // if no change was made to the ID, return the result
  99         // else, return the new id if stripping whitespace made it
 100         //     valid, or return false.
 101         return $result ? $id : false;
 102     }
 103 }
 104
 105 // vim: et sw=4 sts=4