private function _filter_htmlcorrector($text)
{
// Prepare tag lists.
static $no_nesting, $single_use;
if (!isset($no_nesting)) {
// Tags which cannot be nested but are typically left unclosed.
$no_nesting = Arr::map_assoc(array('li', 'p'));
// Single use tags in HTML4
$single_use = Arr::map_assoc(array('base', 'meta', 'link', 'hr', 'br', 'param', 'img', 'area', 'input', 'col', 'frame'));
}
// Properly entify angles.
$text = preg_replace('@<(?=[^a-zA-Z!/]|$)@', '<', $text);
// Split tags from text.
$split = preg_split('/<(!--.*?--|[^>]+?)>/s', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
// Note: PHP ensures the array consists of alternating delimiters and
// literals
// and begins and ends with a literal (inserting $null as required).
$tag = false;
// Odd/even counter. Tag or no tag.
$stack = array();
$output = '';
foreach ($split as $value) {
// Process HTML tags.
if ($tag) {
// Passthrough comments.
if (substr($value, 0, 3) == '!--') {
$output .= '<' . $value . '>';
} else {
list($tagname) = preg_split('/\\s/', strtolower($value), 2);
// Closing tag
if ($tagname[0] == '/') {
$tagname = substr($tagname, 1);
// Discard XHTML closing tags for single use tags.
if (!isset($single_use[$tagname])) {
// See if we possibly have a matching opening tag on
// the stack.
if (in_array($tagname, $stack)) {
// Close other tags lingering first.
do {
$output .= '</' . $stack[0] . '>';
} while (array_shift($stack) != $tagname);
}
// Otherwise, discard it.
}
} else {
// See if we have an identical 'no nesting' tag already
// open and close it if found.
if (count($stack) && $stack[0] == $tagname && isset($no_nesting[$stack[0]])) {
$output .= '</' . array_shift($stack) . '>';
}
// Push non-single-use tags onto the stack
if (!isset($single_use[$tagname])) {
array_unshift($stack, $tagname);
} else {
$value = rtrim($value, ' /') . ' /';
}
$output .= '<' . $value . '>';
}
}
} else {
// Passthrough all text.
$output .= $value;
}
$tag = !$tag;
}
// Close remaining tags.
while (count($stack) > 0) {
$output .= '</' . array_shift($stack) . '>';
}
return $output;
}
