Get $modx->newQuery to show the query string

$criteria->prepare();
echo $criteria->toSQL();

$this->setDebug(true);

/* query code and execution here */
die();

//get params
$resource = $modx->getOption('id', $scriptProperties, $modx->resource->get('id'));
$direction = $modx->getOption('direction', $scriptProperties, false);
$tpl = $modx->getOption('tpl', $scriptProperties, false);
$linktxt = $modx->getOption('linktext', $scriptProperties, false);


if($res = $modx->getObject('modResource', $resource)) {
	
	$menuindex = $res->get('menuindex');
	$parentid = $res->get('parent');
	$c = $modx->newQuery('modResource');
	$c->limit(1);
	switch($direction) {
		case 'next':
		case 'prev':
			$c->where(array('id:!=' => $resource));
			$c->where(array('parent' => $parentid));
			$c->where(array('published' => true));
			$c->where(array('deleted' => false));
			break;
	}
	switch($direction) {
		case 'next':
			//$c->where(array('publishedon:<' => 'date('.$res->get('publishedon').')' ));
                        $c->where("[modResource].[publishedon] > CAST('" . $res->get('publishedon') . "' AS DATETIME) " , xPDOQuery::SQL_AND);
			$c->sortby('publishedon','DESC');
			break;
		case 'prev':
			//$c->where(array('publishedon:>' => 'date('.$res->get('publishedon').')' ));
			$c->sortby('publishedon','ASC');
			break;
	}
//debug
//$c->prepare();
//return 'SQL: ' . $c->toSQL();
	if($linkResource = $modx->getObject('modResource', $c)) {
		// build placeholders
		$placeholders = array(
			'id' => $linkResource->get('id'),
			'pagetitle' => (!empty($linktxt)) ? $linktxt : $linkResource->get('pagetitle'), 
			'longtitle' => (!empty($linktxt)) ? $linktxt : $linkResource->get('longtitle'),
			'publishedon' => (!empty($linktxt)) ? $linktxt : $linkResource->get('publishedon'),
			'menutitle' => (!empty($linktxt)) ? $linktxt : $linkResource->get('menutitle')
		);
		
		// parse chunk
		$chunk = $modx->getObject('modChunk', array('name' => $tpl));
		if(!$chunk) {
			$useChunk = '<a href="[[~[[+id]]]]">[[+menutitle:isempty=`[[+pagetitle]]`]]</a>';
			$chunk = $modx->newObject('modChunk');
			$chunk->setCacheable(false);
			$chunk->setContent($useChunk);
		}
		return $chunk->process($placeholders);
	}else{
		return 'no object found';
	}
}

$c->sortby('publishedon', 'ASC');
$c->sortby('publishedon', 'DESC');