<?php
/**
* Transforms FONT tags to the proper form (SPAN with CSS styling)
*
* This transformation takes the three proprietary attributes of FONT and
* transforms them into their corresponding CSS attributes. These are color,
* face, and size.
*
* @note Size is an interesting case because it doesn't map cleanly to CSS.
* Thanks to
* http://style.cleverchimp.com/font_size_intervals/altintervals.html
* for reasonable mappings.
* @warning This doesn't work completely correctly; specifically, this
* TagTransform operates before well-formedness is enforced, so
* the "active formatting elements" algorithm doesn't get applied.
*/
class HTMLPurifier_TagTransform_Font extends HTMLPurifier_TagTransform
{
/**
* @type string
*/
public $transform_to = 'span';
/**
* @type array
*/
protected $_size_lookup = array(
'0' => 'xx-small',
'1' => 'xx-small',
'2' => 'small',
'3' => 'medium',
'4' => 'large',
'5' => 'x-large',
'6' => 'xx-large',
'7' => '300%',
'-1' => 'smaller',
'-2' => '60%',
'+1' => 'larger',
'+2' => '150%',
'+3' => '200%',
'+4' => '300%'
);
/**
* @param HTMLPurifier_Token_Tag $tag
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return HTMLPurifier_Token_End|string
*/
public function transform($tag, $config, $context)
{
if ($tag instanceof HTMLPurifier_Token_End) {
$new_tag = clone $tag;
$new_tag->name = $this->transform_to;
return $new_tag;
}
$attr = $tag->attr;
$prepend_style = '';
// handle color transform
if (isset($attr['color'])) {
$prepend_style .= 'color:' . $attr['color'] . ';';
unset($attr['color']);
}
// handle face transform
if (isset($attr['face'])) {
$prepend_style .= 'font-family:' . $attr['face'] . ';';
unset($attr['face']);
}
// handle size transform
if (isset($attr['size'])) {
// normalize large numbers
if ($attr['size'] !== '') {
if ($attr['size']{0} == '+' || $attr['size']{0} == '-') {
$size = (int)$attr['size'];
if ($size < -2) {
$attr['size'] = '-2';
}
if ($size > 4) {
$attr['size'] = '+4';
}
} else {
$size = (int)$attr['size'];
if ($size > 7) {
$attr['size'] = '7';
}
}
}
if (isset($this->_size_lookup[$attr['size']])) {
$prepend_style .= 'font-size:' .
$this->_size_lookup[$attr['size']] . ';';
}
unset($attr['size']);
}
if ($prepend_style) {
$attr['style'] = isset($attr['style']) ?
$prepend_style . $attr['style'] :
$prepend_style;
}
$new_tag = clone $tag;
$new_tag->name = $this->transform_to;
$new_tag->attr = $attr;
return $new_tag;
}
}
// vim: et sw=4 sts=4