MODx tags are meant to work with objects that exist, so the results of using a tag with modifiers to display an object that doesn’t exist would probably be unwise even if it worked. Also, boolean (yes/no) system settings might contain a ’0’ which would be interpreted as empty even though they exist and other system settings could contain empty strings.
A simple snippet would be much more efficient anyway and could tell you if a setting doesn’t exist. Something like this:
[[!GetSetting? &systemSetting=`filemanager_path`]]
<?php
/* GetSetting snippet */
$output = $modx->getOption($systemSetting);
if ($output === null ) {
$output = 'Setting Does not exist';
} elseif (empty($s)) {
$output = 'Setting is empty';
}
return $output;
?>
