library/HTMLPurifier/AttrTransform/ImgRequired.php

   1 <?php
   2
   3 // must be called POST validation
   4
   5 /**
   6  * Transform that supplies default values for the src and alt attributes
   7  * in img tags, as well as prevents the img tag from being removed
   8  * because of a missing alt tag. This needs to be registered as both
   9  * a pre and post attribute transform.
  10  */
  11 class HTMLPurifier_AttrTransform_ImgRequired extends HTMLPurifier_AttrTransform
  12 {
  13
  14     /**
  15      * @param array $attr
  16      * @param HTMLPurifier_Config $config
  17      * @param HTMLPurifier_Context $context
  18      * @return array
  19      */
  20     public function transform($attr, $config, $context)
  21     {
  22         $src = true;
  23         if (!isset($attr['src'])) {
  24             if ($config->get('Core.RemoveInvalidImg')) {
  25                 return $attr;
  26             }
  27             $attr['src'] = $config->get('Attr.DefaultInvalidImage');
  28             $src = false;
  29         }
  30
  31         if (!isset($attr['alt'])) {
  32             if ($src) {
  33                 $alt = $config->get('Attr.DefaultImageAlt');
  34                 if ($alt === null) {
  35                     // truncate if the alt is too long
  36                     $attr['alt'] = substr(basename($attr['src']), 0, 40);
  37                 } else {
  38                     $attr['alt'] = $alt;
  39                 }
  40             } else {
  41                 $attr['alt'] = $config->get('Attr.DefaultInvalidImageAlt');
  42             }
  43         }
  44         return $attr;
  45     }
  46 }
  47
  48 // vim: et sw=4 sts=4