PHP Infinitus classification related codes

//Non-recursively get all descendant categories
function get_offspring($pids, $list)
{
 $npid = array();
 $offspring = array();
 $has_child = true;
 while( $has_child)
 {
 $has_child = false;
 foreach($list as $lk => $lv)
 {
 if(in_array($lv['pid'], $pids))
 {
 $offspring[ ] = $lv;
 $npid[] = $lv['cid'];
 unset($list[$lk]);
 $has_child = true;
 }
 }
 $pids = $npid;
 }
 return $offspring;
}
//Use the path field to get the descendant classification
function get_offspring($pid)
{
 $offspring = array();
 $cats = $this->getList('cat_id,cat_name,parent_id, cat_path', array(), 0, -1);
 foreach($cats as $cv)
 {
 if(in_array($pid, explode(',', $cv['cat_path'])))
 {
 $offspring[] = $cv;
 }
 }
 return $offspring;
}
//Update descendant classification path
function update_offspring_path($pid, $ppath)
{
 if($ppath == ',')
 {
 $ppath = '';
 }
 $offspring = $this->get_offspring($pid);

 foreach($offspring as $ov)
 {
 $ov['cat_path'] = substr($ ov['cat_path'], 0, strlen($ov['cat_path'])-1);
 $old_path = explode(',', $ov['cat_path']);
 foreach($old_path as $oldk => $oldv)
 {
 if($oldv == $pid)
 {
 break;
 }
 unset($old_path[$oldk]);
 }
 $new_path = $ppath.implode(',' , $old_path).',';
 if(!$this->update(array('cat_path'=>$new_path), array('cat_id'=>$ov['cat_id'])))
 {
 return false;
 }
 }
 return true;
}
//Organize the list into a tree shape
function get_tree_list($pid, $arr, &$r)
{
 foreach($arr as $k = > $v)
 {
 if($v['parent_id'] == $pid)
 {
 if(isset($r[$pid]))//Set the subclass tag
 {
 $r[ $pid]['has_child'] = 1;
 }

 $v['cat_path'] = trim($v['cat_path']);//Calculate depth
 $path_str = substr($v['cat_path' ], 0, strlen($v['cat_path'])-1);
 if($path_str == '')
 {
 $v['deep'] = 0;
 }
 else
 {
 $v ['deep'] = count(explode(',', $path_str));
 }

 $v['format'] = str_repeat(' ', 6*$v['deep']);/ /Calculate indent

 $r[$v['cat_id']] = $v;//Add to ordered list

 unset($arr[$k]);//Add and remove from unordered list

 $this->get_tree_list($v['cat_id'], $arr, $r);
 }
 }
}

Infinitus, PHP