lib/htmlpurifier/library/HTMLPurifier/TagTransform/Font.php

   1 <?php
   2
   3 /**
   4  * Transforms FONT tags to the proper form (SPAN with CSS styling)
   5  *
   6  * This transformation takes the three proprietary attributes of FONT and
   7  * transforms them into their corresponding CSS attributes.  These are color,
   8  * face, and size.
   9  *
  10  * @note Size is an interesting case because it doesn't map cleanly to CSS.
  11  *       Thanks to
  12  *       http://style.cleverchimp.com/font_size_intervals/altintervals.html
  13  *       for reasonable mappings.
  14  * @warning This doesn't work completely correctly; specifically, this
  15  *          TagTransform operates before well-formedness is enforced, so
  16  *          the "active formatting elements" algorithm doesn't get applied.
  17  */
  18 class HTMLPurifier_TagTransform_Font extends HTMLPurifier_TagTransform
  19 {
  20
  21     public $transform_to = 'span';
  22
  23     protected $_size_lookup = array(
  24         '0' => 'xx-small',
  25         '1' => 'xx-small',
  26         '2' => 'small',
  27         '3' => 'medium',
  28         '4' => 'large',
  29         '5' => 'x-large',
  30         '6' => 'xx-large',
  31         '7' => '300%',
  32         '-1' => 'smaller',
  33         '-2' => '60%',
  34         '+1' => 'larger',
  35         '+2' => '150%',
  36         '+3' => '200%',
  37         '+4' => '300%'
  38     );
  39
  40     public function transform($tag, $config, $context) {
  41
  42         if ($tag instanceof HTMLPurifier_Token_End) {
  43             $new_tag = clone $tag;
  44             $new_tag->name = $this->transform_to;
  45             return $new_tag;
  46         }
  47
  48         $attr = $tag->attr;
  49         $prepend_style = '';
  50
  51         // handle color transform
  52         if (isset($attr['color'])) {
  53             $prepend_style .= 'color:' . $attr['color'] . ';';
  54             unset($attr['color']);
  55         }
  56
  57         // handle face transform
  58         if (isset($attr['face'])) {
  59             $prepend_style .= 'font-family:' . $attr['face'] . ';';
  60             unset($attr['face']);
  61         }
  62
  63         // handle size transform
  64         if (isset($attr['size'])) {
  65             // normalize large numbers
  66             if ($attr['size'] !== '') {
  67                 if ($attr['size']{0} == '+' || $attr['size']{0} == '-') {
  68                     $size = (int) $attr['size'];
  69                     if ($size < -2) $attr['size'] = '-2';
  70                     if ($size > 4)  $attr['size'] = '+4';
  71                 } else {
  72                     $size = (int) $attr['size'];
  73                     if ($size > 7) $attr['size'] = '7';
  74                 }
  75             }
  76             if (isset($this->_size_lookup[$attr['size']])) {
  77                 $prepend_style .= 'font-size:' .
  78                   $this->_size_lookup[$attr['size']] . ';';
  79             }
  80             unset($attr['size']);
  81         }
  82
  83         if ($prepend_style) {
  84             $attr['style'] = isset($attr['style']) ?
  85                 $prepend_style . $attr['style'] :
  86                 $prepend_style;
  87         }
  88
  89         $new_tag = clone $tag;
  90         $new_tag->name = $this->transform_to;
  91         $new_tag->attr = $attr;
  92
  93         return $new_tag;
  94
  95     }
  96 }
  97
  98 // vim: et sw=4 sts=4