Convert a flat array to a nested array using materialized path

Question

I have some categories that I need to convert to nested array (tree). I use materialized path to make a tree and I work in PHP. Here's a print_r of what I have:

Array
(
    [0] => Array
        (
            [_id] => mac
            [name] => Mac
            [path] => null
        )

    [1] => Array
        (
            [_id] => ipod
            [name] => iPod
            [path] => null
        )

    [2] => Array
        (
            [_id] => imac
            [name] => iMac
            [path] => ,mac,
        )

    [3] => Array
        (
            [_id] => imac2001
            [name] => iMac 2001
            [path] => ,mac,imac,
        )

    [4] => Array
        (
            [_id] => imac2002
            [name] => iMac 2002
            [path] => ,mac,imac,
        )

    [5] => Array
        (
            [_id] => imac2003
            [name] => iMac 2003
            [path] => ,mac,imac,
        )

)

I tried to make it but I get lost in the whole idea of recursive function.

UPDATE :

Here's what I would like to have ultimately :

Array
(
    [0] => Array
        (
            [_id] => mac
            [name] => Mac
            [path] => null
            [children] =>
                [0] => Array
                    (
                        [_id] => imac
                        [name] => iMac
                        [path] => ,mac,
                        [children] =>
                            [0] => Array
                                (
                                    [_id] => imac2001
                                    [name] => iMac 2001
                                    [path] => ,mac,imac,
                                )

                            [1] => Array
                                (
                                    [_id] => imac2002
                                    [name] => iMac 2002
                                    [path] => ,mac,imac,
                                )

                            [2] => Array
                                (
                                    [_id] => imac2003
                                    [name] => iMac 2003
                                    [path] => ,mac,imac,
                                )
                    )
        )

    [1] => Array
        (
            [_id] => ipod
            [name] => iPod
            [path] => null
        )
)

I'd like to show you what I already have coded but It's far from working so nothing good to see in my opinion.

So we see what you have. But the questions are: what you **need** and what you **have done**? — u_mulder, Jan 31 '15 at 20:56
Does it have to be an array or can it also be an object? Also, is the array always in the correct order? So the paths follow up on each other? — Hugo Delsing, Jan 31 '15 at 21:04

score 0 · Answer 1 · answered Feb 01 '15 at 17:26

I have found a solution. It's working for me so here it is:

<?php

$categories = Array
(
    [0] => Array
        (
            ["_id"] => "mac"
            ["name"] => "Mac"
            ["path"] => null
        )

    [1] => Array
        (
            ["_id"] => "ipod"
            ["name"] => "iPod"
            ["path"] => null
        )

    [2] => Array
        (
            ["_id"] => "imac"
            ["name"] => "iMac"
            ["path"] => ",mac,"
        )

    [3] => Array
        (
            ["_id"] => "imac2001"
            ["name"] => "iMac 2001"
            ["path"] => ",mac,imac,"
        )

    [4] => Array
        (
            ["_id"] => "imac2002"
            ["name"] => "iMac 2002"
            ["path"] => ",mac,imac,"
        )

    [5] => Array
        (
            ["_id"] => "imac2003"
            ["name"] => "iMac 2003"
            ["path"] => ",mac,imac,"
        )
)

$categoriesNested = sortTree($categories);

function sortTree(&$categories, $parent = null)
{
    $result = array();

    foreach($categories as $key => $cat)
    {
        if($parent == null)
        {
            $temp = $cat;
            unset($categories[$key]);
            $temp["children"] = $this->sortTree($categories, $cat);
            $result[] = $temp;
        }
        else
        {
            $tempPath = array_values(array_filter(explode(',', $cat["path"])));
            $directParent = array_pop($tempPath);
            if ($parent["_id"] == $directParent)
            {
                $temp = $cat;
                unset($categories[$key]);
                $temp["children"] = $this->sortTree($categories, $cat);
                $result[] = $temp;
            }
        }
    }

    if (empty($result))
        return null;
    else
        return $result;
}

Convert a flat array to a nested array using materialized path

1 Answers1