Convert multidimensional array to nested set array - php

Question

im having a little problem i need some help with.
Im trying to convert a multidimensional array into a flatten array with nested set values right and left like so:
$array = {
'id' => 1
'name' => 'john'
'childs' => array(
array(
'id' => 1
'name' => 'jane'
)
)
}
to
$array = {
array(
'id' => 1,
'name' => 'john'
'left' => '1'
'right' => '4'
),
array(
'id' => 1,
'name' => 'jane'
'left' => '2'
'right' => '3'
)
}
Any help is appreciated!

Answer 1

I asked a very similar question and got a result, so thought I'd send it on for you. I realise this is quite an old topic, but still worth getting an answer. I've included my data, but would be easily adapted for yours.
$JSON = '[{"id":1,"children":[{"id":2,"children":[{"id":3},{"id":4}]},{"id":5}]}]';
$cleanJSON = json_decode($JSON,true);
$a_newTree = array();
function recurseTree($structure,$previousLeft)
{
global $a_newTree; // Get global Variable to store results in.
$indexed = array(); // Bucket of results.
$indexed['id'] = $structure['id']; // Set ID
$indexed['left'] = $previousLeft + 1; // Set Left
$lastRight = $indexed['left'];
$i_count = 0;
if ($structure['children'])
{
foreach ($structure['children'] as $a_child)
{
$lastRight = recurseTree($structure['children'][$i_count],$lastRight);
$i_count++;
}
}
$indexed['right'] = $lastRight + 1; // Set Right
array_push($a_newTree,$indexed); // Push onto stack
return $indexed['right'];
}
recurseTree($cleanJSON[0],0);
print_r($a_newTree);

Answer 2

function restructRecursive($array, $left = 1) {
if (isset($array['childs'])) {
$result = array();
foreach ($array['childs'] as $child) {
$result = array_merge($result, restructRecursive($child, $left+1));
}
unset($array['childs']);
}
$array['left'] = $left;
return array_merge(array($array), $result);
}
$newStruct = restructRecursive($oldStruct);

Answer 3

For anyone coming here and looking for a solution, loneTraceur's solution works fine. However, I needed one in OOP, so here is my version of it.
<?php
class NestedSet
{
protected $tree = [];
public function deconstruct($tree, $left = 0)
{
$this->flattenTree($tree, $left);
return $this->tree;
}
protected function flattenTree($tree, $left)
{
$indexed = [];
$indexed['id'] = $tree['id'];
$indexed['_lft'] = $left + 1;
$right = $indexed['_lft'];
if (isset($tree['children']) && count($tree['children'])) {
foreach ($tree['children'] as $child) {
$right = $this->flattenTree($child, $right);
}
}
$indexed['_rgt'] = $right + 1;
$this->tree[] = $indexed;
return $indexed['_rgt'];
}
}
You would run it like this:
$NestedSet = new NestedSet;
$flat = $NestedSet->deconstruct($tree):
This code is based on the other answer.