library/HTMLPurifier/TagTransform/Font.php

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