[Summary view]

   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       * @type string
  22       */
  23      public $transform_to = 'span';
  24  
  25      /**
  26       * @type array
  27       */
  28      protected $_size_lookup = array(
  29          '0' => 'xx-small',
  30          '1' => 'xx-small',
  31          '2' => 'small',
  32          '3' => 'medium',
  33          '4' => 'large',
  34          '5' => 'x-large',
  35          '6' => 'xx-large',
  36          '7' => '300%',
  37          '-1' => 'smaller',
  38          '-2' => '60%',
  39          '+1' => 'larger',
  40          '+2' => '150%',
  41          '+3' => '200%',
  42          '+4' => '300%'
  43      );
  44  
  45      /**
  46       * @param HTMLPurifier_Token_Tag $tag
  47       * @param HTMLPurifier_Config $config
  48       * @param HTMLPurifier_Context $context
  49       * @return HTMLPurifier_Token_End|string
  50       */
  51      public function transform($tag, $config, $context)
  52      {
  53          if ($tag instanceof HTMLPurifier_Token_End) {
  54              $new_tag = clone $tag;
  55              $new_tag->name = $this->transform_to;
  56              return $new_tag;
  57          }
  58  
  59          $attr = $tag->attr;
  60          $prepend_style = '';
  61  
  62          // handle color transform
  63          if (isset($attr['color'])) {
  64              $prepend_style .= 'color:' . $attr['color'] . ';';
  65              unset($attr['color']);
  66          }
  67  
  68          // handle face transform
  69          if (isset($attr['face'])) {
  70              $prepend_style .= 'font-family:' . $attr['face'] . ';';
  71              unset($attr['face']);
  72          }
  73  
  74          // handle size transform
  75          if (isset($attr['size'])) {
  76              // normalize large numbers
  77              if ($attr['size'] !== '') {
  78                  if ($attr['size'][0] == '+' || $attr['size'][0] == '-') {
  79                      $size = (int)$attr['size'];
  80                      if ($size < -2) {
  81                          $attr['size'] = '-2';
  82                      }
  83                      if ($size > 4) {
  84                          $attr['size'] = '+4';
  85                      }
  86                  } else {
  87                      $size = (int)$attr['size'];
  88                      if ($size > 7) {
  89                          $attr['size'] = '7';
  90                      }
  91                  }
  92              }
  93              if (isset($this->_size_lookup[$attr['size']])) {
  94                  $prepend_style .= 'font-size:' .
  95                      $this->_size_lookup[$attr['size']] . ';';
  96              }
  97              unset($attr['size']);
  98          }
  99  
 100          if ($prepend_style) {
 101              $attr['style'] = isset($attr['style']) ?
 102                  $prepend_style . $attr['style'] :
 103                  $prepend_style;
 104          }
 105  
 106          $new_tag = clone $tag;
 107          $new_tag->name = $this->transform_to;
 108          $new_tag->attr = $attr;
 109  
 110          return $new_tag;
 111      }
 112  }
 113  
 114  // vim: et sw=4 sts=4