How to traverse JSON recursively?

Question

PHP

I'm trying to parse a bookmark file from Google Chrome. As you know, this is just a JSON file. And here's something stuck on the recursion. Displays an empty table and at least crack. Where did I screw up?

// читаем файл с закладками в формате JSON
$str = file_get_contents('Bookmarks');
$ar = json_decode($str);
$chld = $ar->roots->other->children;
$marks = array();
 
function recursiveJSON2ARRAY($obj, $arr){
  foreach($obj as $v){
    if(isset($v->children) && is_array($v->children) && count($v->children) > 0){
      foreach($v->children as $child){
        if(isset($child->url)){
          $arr[$child->date_added] = array('name'=>$child->name, 'url'=>$child->url);
        }
        else{
          recursiveJSON2ARRAY($child, $arr);
        }
      }
    }
    else{
      if(isset($v->url)){
        $arr[$v->date_added] = array('name'=>$v->name, 'url'=>$v->url);
      }
    }
  }
}

recursiveJSON2ARRAY($chld, $marks);

//krsort($marks); // Reverse sort the bookmarks by date added
 
$table = '<table cellspacing="2" cellpadding="2" border="1" width="600"><tr><td><b>Date</b></td><td><b>Name</b></td><td><b>URL</b></td></tr>';
foreach($marks as $date=>$mark)
{
  $table .= '<tr><td>'.date('H:m:s d-m-Y', $date).'</td><td>'.$mark['name'].'</td><td><a href="'.$mark['url'].'" target="_blank">'.$mark['url'].'</a></td></tr>';
}
$table .= '</table>';
 
echo $table;

Answer 1

Maybe $arr should be passed by reference?

Answer 2

$ar = json_decode($str, TRUE); // will return an array. php.net/manual/en/function.json-decode.php
$names= array_column($ar, 'name'); // recursively find "name" php.net/manual/en/function.array-column.php

Answer 3

Madridian Fox is right.
Do it like this
function recursiveJSON2ARRAY($obj, &$arr){

Answer 4

<?php

error_reporting(E_ALL);
ini_set('display_errors', 1);

$file = '/path/to/file';
$array = json_decode(file_get_contents($file), true);

function buildBookmarks($bookmarks, $name, &$output = [])
{
    if (!isset($bookmarks['children'])) {
        $output[$name][] = $bookmarks;

        return;
    }

    foreach ($bookmarks['children'] as $child) {
        if ($bookmark = buildBookmarks($child, $array['name'], $output)) {
            $output[$name][] = $bookmark;
        }
    }
}

buildBookmarks($array['roots']['bookmark_bar'], 'root', $bookmarks);

foreach ($bookmarks as $folder => $children) {
    foreach ($children as $bookmark) {

        echo "<pre>";
        var_dump($folder, $bookmark);
        echo "</pre>";
        exit("File: " . __FILE__ . " Line: " . __LINE__);
    }
}