flattened_JSON_into_a_hierarchical_JSON.php

<?php
$json ='[
  {
    "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"
  }
]';
$json = json_decode($json,true);
$outPut = generateArrayTree($json);

echo json_encode($outPut);


function generateArrayTree($datas, $parent = 0, $depth=0){
    $length=count($datas);    $branch = array();
    if($length === 0 || $depth > 1000) return '';
    for($i=0; $i < $length; $i++){
        if($datas[$i]['parent'] == $parent){$node=array();
            $children =generateArrayTree($datas, $datas[$i]['id'], $depth+1);
              $node['id'] = $datas[$i]['id'];
              $node['parent'] = $datas[$i]['parent'];
              $node['name'] = $datas[$i]['name'];
              if($children){
              $node['children']=$children;
              }
              $branch[]= $node;
                   // $branch[] = array('id' => $datas[$i]['id'], 'parent' => $datas[$i]['parent'],'name' => $datas[$i]['name'], 'children' => generateArrayTree($datas, $datas[$i]['id'], $depth+1)            ); 


        }
    }
    return $branch;
}


?>