RecursiveParentChild.php

RecursiveParentChild.php

<?php

$arr = '[{"id":8,"parent":4,"name":"Food & Lifestyle"},{"id":2,"parent":1,"name":"Mobile Phones"},{"id":1,"parent":0,"name":"Electronics"},{"id":3,"parent":1,"name":"Laptops"},{"id":5,"parent":4,"name":"Fiction"},{"id":4,"parent":0,"name":"Books"},{"id":6,"parent":4,"name":"Non-fiction"},{"id":7,"parent":1,"name":"Storage"}]';

$t = buildTree($arr);

print_r($t);

function buildTree(array $flatList)
{
    $grouped = [];
    foreach ($flatList as $node){
        $grouped[$node['parent']][] = $node;
    }

    $fnBuilder = function($siblings) use (&$fnBuilder, $grouped) {
        foreach ($siblings as $k => $sibling) {
            $id = $sibling['id'];
            if(isset($grouped[$id])) {
                $sibling['children'] = $fnBuilder($grouped[$id]);
            }
            $siblings[$k] = $sibling;
        }
        return $siblings;
    };

    return $fnBuilder($grouped[0]);
}

function build_tree(&$items, $parentId = null) {
    $treeItems = [];
    foreach ($items as $idx => $item) {
        if((empty($parentId) && empty($item['parent'])) || (!empty($item['parent']) && !empty($parentId) && $item['parent'] == $parentId)) {
            $items[$idx]['children'] = build_tree($items, $items[$idx]['id']);
            $treeItems []= $items[$idx];
        }
    }

    return $treeItems;
}



?>