php shift in a hierarchy array

Question

Hello. I have the next array:

Array(
   [id] => 1
   [children] => Array(
      [2] => Array(
         [id] => 2
         [inactive] => true
         [children] => Array(
            [4] => Array(
               [id] => 4
               [children] => Array()
            )
         )
      )
      [3] => array(
         [id] => 3
         [children] => Array(
            [5] => Array(
               [id] => 5
               [inactive] => true
               [children] => Array()
            )
         )
      )
   )
)

I need to remove elements from this array, which have [inactive] = true. But my problem in the next. I should shift the array elements. Output should be:

Array(
   [id] => 1
   [children] => Array(
      [4] => Array(
         [id] => 4
         [children] => Array()
      )
      [3] => array(
         [id] => 3
         [children] => Array(
         )
      )
   )
)

It is my function. But it removes array element with all his subelements.

public function deleteInactive($userTree)
{
    if (!empty($userTree)) {
        foreach($userTree['children'] as $userId => &$user) {
            if (array_key_exists('inactive', $user)) {
                $userTree['children'] += $user['children'];
                unset($userTree['children'][$userId]);
                $this->deleteInactive($userTree);
                break;
            }
            $this->deleteInactive($user);
        }
    }
    return $userTree;
}

Can you help me to modify this function?

Thank you very much.

Answer 1

Before unsetting a node, you need to attach the children to the parent of the node. This doesn't happen (the code only unsets), so the children are lost.

Answer 2

Try this function, it should do as you asked.

<?php
function deleteInactive($children) {
    $copy = $children;
    foreach ($copy as $key => $child) {
        if (!empty($child['inactive']) && $child['inactive'] === true) {
            unset($children[$key]);
            $children = deleteInactive($child['children']);
        } elseif (!empty($child['children']) && is_array($child['children'])) {
            $children[$key]['children'] = deleteInactive($child['children']);
        }
    }
    return $children;
} ?>

Your FIRST array MUST be a valid children array also, you can call it like this against your array you listed.

deleteInactive(array('1' => $array));