public static function renderTableOfContents(PhutilRemarkupEngine $engine)
{
$key = self::KEY_HEADER_TOC;
$anchors = $engine->getTextMetadata($key, array());
if (count($anchors) < 2) {
// Don't generate a TOC if there are no headers, or if there's only
// one header (since such a TOC would be silly).
return null;
}
$depth = 0;
$toc = array();
foreach ($anchors as $anchor => $info) {
list($level, $name) = $info;
while ($depth < $level) {
$toc[] = '<ul>';
$depth++;
}
while ($depth > $level) {
$toc[] = '</ul>';
$depth--;
}
$toc[] = phutil_render_tag('li', array(), phutil_render_tag('a', array('href' => '#' . $anchor), phutil_escape_html($name)));
}
while ($depth > 0) {
$toc[] = '</ul>';
$depth--;
}
return implode("\n", $toc);
}
