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     /**
  12      * @type HTMLPurifier_URIParser
  13      */
  14     private $parser;
  15
  16     public function __construct()
  17     {
  18         $this->parser = new HTMLPurifier_URIParser();
  19     }
  20
  21     /**
  22      * @param array $attr
  23      * @param HTMLPurifier_Config $config
  24      * @param HTMLPurifier_Context $context
  25      * @return array
  26      */
  27     public function transform($attr, $config, $context)
  28     {
  29         if (!isset($attr['href'])) {
  30             return $attr;
  31         }
  32
  33         // XXX Kind of inefficient
  34         $url = $this->parser->parse($attr['href']);
  35         $scheme = $url->getSchemeObj($config, $context);
  36
  37         if ($scheme->browsable && !$url->isLocal($config, $context)) {
  38             if (isset($attr['rel'])) {
  39                 $rels = explode(' ', $attr['rel']);
  40                 if (!in_array('nofollow', $rels)) {
  41                     $rels[] = 'nofollow';
  42                 }
  43                 $attr['rel'] = implode(' ', $rels);
  44             } else {
  45                 $attr['rel'] = 'nofollow';
  46             }
  47         }
  48         return $attr;
  49     }
  50 }
  51
  52 // vim: et sw=4 sts=4