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     public function transform($attr, $config, $context) {
  15
  16         $src = true;
  17         if (!isset($attr['src'])) {
  18             if ($config->get('Core.RemoveInvalidImg')) return $attr;
  19             $attr['src'] = $config->get('Attr.DefaultInvalidImage');
  20             $src = false;
  21         }
  22
  23         if (!isset($attr['alt'])) {
  24             if ($src) {
  25                 $alt = $config->get('Attr.DefaultImageAlt');
  26                 if ($alt === null) {
  27                     // truncate if the alt is too long
  28                     $attr['alt'] = substr(basename($attr['src']),0,40);
  29                 } else {
  30                     $attr['alt'] = $alt;
  31                 }
  32             } else {
  33                 $attr['alt'] = $config->get('Attr.DefaultInvalidImageAlt');
  34             }
  35         }
  36
  37         return $attr;
  38
  39     }
  40
  41 }
  42
  43 // vim: et sw=4 sts=4