function getTagWithLabel($label)
{
assert(labelExists($label));
global $database;
$sql = $database->prepare('SELECT tag FROM tags WHERE label = :label AND active = "TRUE"');
$sql->bindParam(':label', $label);
if ($sql->execute()) {
return $sql->fetchColumn();
}
return "ZZZZ";
}
function parseReferences($string)
{
// look for \ref before MathJax can and see if they point to existing tags
$references = array();
preg_match_all('/\\\\ref{[\\w-]*}/', $string, $references);
foreach ($references[0] as $reference) {
// get the label or tag we're referring to, nothing more
$target = substr($reference, 5, -1);
// we're referring to a tag
if (isValidTag($target)) {
// regardless of whether the tag exists we insert the link, the user is responsible for meaningful content
$string = str_replace($reference, '[`' . $target . '`](' . href('tag/' . $target) . ')', $string);
} else {
// might it be that he is referring to a "local" label, i.e. in the same chapter as the tag?
// TODO: Is it worth it to do this?
if (!labelExists($target)) {
$tag = getTag(strtoupper($_GET['tag']));
// let's try it with the current chapter in front of the label
$target = $tag["file"] . '-' . $target;
}
// the label (potentially modified) exists in the database (and it is active), so the user is probably referring to it
// if he declared a \label{} in his string with this particular label value he's out of luck
if (labelExists($target)) {
$tag = getTagWithLabel($target);
$string = str_replace($reference, '[`' . $tag . '`](' . href('tag/' . $tag) . ')', $string);
}
}
}
return $string;
}