How to reorder nested elements in PHP? - php

Question

I have a list of nested items (categories) I would like to reorganize, by ordering and nesting depth. I will try to explain:
When I submit a form with jQuery by clicking on blue button SAVE, it process a function inside models/categories_model.php:
public function organize($items){
if( count($items)){
foreach($items as $order => $item){
if($item['item_id'] != ''){
echo '<pre>'.$order.'</pre>';
$data = array(
'pid' => (int) $item['parent_id'],
'ordering' => $order
);
$this->db
->set($data)
->where($this->_primary_key, $item['item_id'])
->update($this->_table_name);
}
}
}
}
It saves that list like this:
1
2
3
4
5
6
7
8
9
10
Instead of saving it like this:
1
1
2
3
4
2
1
2
3
1
2
1
2
3
3
Instead of getting $order value one by one, it should take into the account it's nested items and start counting the $order from 1, and not continuing a counting from it's parent item.
So when I save it, I want them to be ordered like this, but don't know how to do it:
Someone know how to make it work with nested items pls?

Answer 1

If method recieves items in correct order, this should work:
public function organize($items)
{
if (!empty($items)) {
$orderByPid = array();
foreach ($items as $item) {
if($item['item_id'] != '') {
if (!isset($orderByPid[$item['parent_id']])) {
$orderByPid[$item['parent_id']] = 0;
}
$data = array(
'pid' => (int) $item['parent_id'],
'ordering' => ++$orderByPid[$item['parent_id']]
);
$this->db
->set($data)
->where($this->_primary_key, $item['item_id'])
->update($this->_table_name);
}
}
}
}