library/HTMLPurifier/AttrTransform/Nofollow.php

   1 <?php
   2
   3 // must be called POST validation
   4
   5 /**
   6  * Adds rel="nofollow" to all outbound links.  This transform is
   7  * only attached if Attr.Nofollow is TRUE.
   8  */
   9 class HTMLPurifier_AttrTransform_Nofollow extends HTMLPurifier_AttrTransform
  10 {
  11     private $parser;
  12
  13     public function __construct() {
  14         $this->parser = new HTMLPurifier_URIParser();
  15     }
  16
  17     public function transform($attr, $config, $context) {
  18
  19         if (!isset($attr['href'])) {
  20             return $attr;
  21         }
  22
  23         // XXX Kind of inefficient
  24         $url = $this->parser->parse($attr['href']);
  25         $scheme = $url->getSchemeObj($config, $context);
  26
  27         if (!is_null($url->host) && $scheme !== false && $scheme->browsable) {
  28             if (isset($attr['rel'])) {
  29                 $rels = explode(' ', $attr);
  30                 if (!in_array('nofollow', $rels)) {
  31                     $rels[] = 'nofollow';
  32                 }
  33                 $attr['rel'] = implode(' ', $rels);
  34             } else {
  35                 $attr['rel'] = 'nofollow';
  36             }
  37         }
  38
  39         return $attr;
  40
  41     }
  42
  43 }
  44
  45 // vim: et sw=4 sts=4