recursive get resource children in front-end

 $parent = $modx->resource->get('id');
 
function getrchild($child){
	global $zoutput ;
	if($child->hasChildren()){
		$itschild = $child->getMany('Children');
		foreach($itschild as $value){
			$zoutput  .= $value->get('longtitle')."<br>";
			getrchild($value);
		}
	}  
	return $zoutput;
} 
 
  
$c = $modx->newQuery('modResource');
$whereArray = array(
   'parent' => $parent
);
$c->where($whereArray);
$c->sortby('menuindex','asc');
$children = $modx->getCollection('modResource',$c);

foreach ($children as $child) {
	   
	$output .= $child->get('longtitle')."<br>";
	$output .= getrchild($child);
  
}
//$output.=  $modx->getChunk ('download_table'  , array( )  ); 
return $output;

// Recursive function - Since you'll be doing it with every resource,
// and Queries have limits, best to do it all in here.
function getMyChildren($parent, $atDepth, $toDepth)
{//Include MODX Object
    global $modx;
    $q = $modx->newQuery(
        'modResource',
        array('parent'=>$parent)
    );
    $q->sortby('menuindex', 'ASC');
    $q->limit(999);              // <-- DO set this appropriately (really, I mean it)
    $q->prepare();
    $children = $modx->getCollection('modResource', $q);

    $output = array();
//CYA - Don't cycle, if children don't exist
    if (!empty($children))
    {//Cycle through all children
        foreach ($children as $key => $child)
        {//CYA - Don't output if it doesn't exist
            if (!empty($child))
            {
               $output[] = $child->get('longtitle') . "\n";
            // Recursively add Children
               if ($toDepth >= $atDepth +1)
                   $output[] = implode("\n", getMyChildren($child->get('id'), $atDepth + 1, $toDepth));
            }
        }
    }
    return $output;
}

//CYA - Make sure starting ID exists
$start = $modx->getObject('modResource', $fromID);  // <-- This is based on parameterized code.
                                               // You can change to $modx->resource->get('id')   
if (!empty($start)
{   $output = $start->get('longtitle') . "\n";
    $output .= implode("\n", getMyChildren($fromID, 1, $toDepth));
}
return $output;

if ($toDepth == 0 || $toDepth >= $atDepth +1 )