How to reformat a nested array?

Question

I have a stored unlimited nested levels array with unwanted extra data.

$arr = array(
    array(
        'name' => 'item1',
        'level' => 0,
        'extra_key' => 'some_data',
        'children' => array(
            'name' => 'sub-item1',
            'level' => 1,
            'extra_key' => 'some_data',
            'children' => array(
                'name' => 'sub-sub-item1',
                'level' => 2,
                'extra_key' => 'some_data',
                'children' => array()
            ),
            array(
                'name' => 'sub-sub2-item1',
                'level' => 2,
                'extra_key' => 'some_data',
                'children' => array()
            ),
        )
    ),
    array(
        'name' => 'item2',
        'level' => 0,
        'extra_key' => 'some_data',
        'children' => array(
            'name' => 'sub-item2',
            'level' => 2,
            'extra_key' => 'some_data',
            'children' => array(
                'name' => 'sub-sub-item2',
                'level' => 2,
                'extra_key' => 'some_data',
                'children' => array()
            ),
            array(
                'name' => 'sub-sub2-item2',
                'level' => 2,
                'extra_key' => 'some_data',
                'children' => array()
            ),
        )
    ),
    array(
        'name' => 'item3',
        'level' => 0,
        'extra_key' => 'some_data',
        'children' => array(
            'name' => 'sub-item3',
            'level' => 1,
            'extra_key' => 'some_data',
            'children' => array(
                'name' => 'sub-sub-item3',
                'level' => 2,
                'extra_key' => 'some_data',
                'children' => array()
            ),
            array(
                'name' => 'sub-sub2-item3',
                'level' => 2,
                'extra_key' => 'some_data',
                'children' => array()
            ),
        )
    ),
);

Expected output array:

$arr = array(
    array(
        'name' => 'item1',
        'nodes' => array(
            'name' => 'sub-item1',
            'nodes' => array(
                'name' => 'sub-sub-item1',
                'nodes' => array()
            ),
            array(
                'name' => 'sub-sub2-item1',
                'nodes' => array()
            ),
        )
    ),
    array(
        'name' => 'item2',
        'nodes' => array(
            'name' => 'sub-item2',
            'nodes' => array(
                'name' => 'sub-sub-item2',
                'nodes' => array()
            ),
            array(
                'name' => 'sub-sub2-item2',
                'nodes' => array()
            ),
        )
    ),
    array(
        'name' => 'item3',
        'nodes' => array(
            'name' => 'sub-item3',
            'nodes' => array(
                'name' => 'sub-sub-item3',
                'nodes' => array()
            ),
            array(
                'name' => 'sub-sub2-item3',
                'nodes' => array()
            ),
        )
    )
);

I want to remove unwanted keys like level , extra_key from all levels and i want also to change the name of the key children to nodes then reproduce the same array with the same structure with the new format.

How can i achieve that?

I tried to do it by recursive function but i failed to reproduce the same structrue

Answer 1

Your structure doesn't make sense, probably because of that you was unable to write recursive function. If it is possible to change structure, I would suggest this one (with reformat function implementation):

<?php

$actual = array(
    array(
        'name' => 'item1',
        'level' => 0,
        'extra_key' => 'some_data',
        'children' => array(
            array(
                'name' => 'sub-item1',
                'level' => 1,
                'extra_key' => 'some_data',
                'children' => array(
                    array(
                        'name' => 'sub-sub-item1',
                        'level' => 2,
                        'extra_key' => 'some_data',
                        'children' => array()
                    ),
                    array(
                        'name' => 'sub-sub2-item1',
                        'level' => 2,
                        'extra_key' => 'some_data',
                        'children' => array()
                    ),
                )
            ),
        )
    ),
);

$expected = array(
    array(
        'name' => 'item1',
        'nodes' => array(
            array(
                'name' => 'sub-item1',
                'nodes' => array(
                    array(
                        'name' => 'sub-sub-item1',
                        'nodes' => array()
                    ),
                    array(
                        'name' => 'sub-sub2-item1',
                        'nodes' => array()
                    ),
                ),
            ),
        )
    ),
);

function change_array($original)
{
    return array_map('change_node', $original);
}

function change_node($node)
{
    return [
        'name' => $node['name'],
        'nodes' => array_map('change_node', $node['children']),
    ];
}

var_dump($expected === change_array($actual));