CODEWITHSUNDEEP
phpmysqlrecursiontree
user1802209
user1802209

Reputation: 97

Recursive category tree in php

I have this sql table

I have this sql table

How to return it with php like?

Root1
- SubCat 1
-- SubSubCat 1
- SubCat 2
Root2

I found this, but i cant return it in form, that i need. But the script still displays all categories, first as a sub, and then as root.

How to make it?

Upvotes: 0

Views: 3540

Answers (1)

Pouki
Pouki

Reputation: 1664

This does the job:

$items = array(
        (object) array('id' => 42, 'sub_id' => 1),
        (object) array('id' => 43, 'sub_id' => 42),
        (object) array('id' => 1, 'sub_id' => 0),
);

$childs = array();

foreach($items as $item)
    $childs[$item->sub_id][] = $item;

foreach($items as $item) if (isset($childs[$item->id]))
    $item->childs = $childs[$item->id];

$tree = $childs[0];

print_r($tree);

This works by first indexing categories by parent_id. Then for each category, we just have to set category->childs to childs[category->id], and the tree is built !

So, now $tree is the categories tree. It contains an array of items with sub_id=0, which themselves contain an array of their childs, which themselves ...

Output of print_r($tree):

stdClass Object
(
    [id] => 1
    [sub_id] => 0
    [childs] => Array
    (
        [0] => stdClass Object
            (
                [id] => 42
                [sub_id] => 1
                [childs] => Array
                    (
                        [0] => stdClass Object
                            (
                                [id] => 43
                                [sub_id] => 42
                            )

                    )

            )

    )

)

So here is the final function:

function buildTree($items) {

    $childs = array();

    foreach($items as $item)
        $childs[$item->sub_id][] = $item;

    foreach($items as $item) if (isset($childs[$item->id]))
        $item->childs = $childs[$item->id];

    return $childs[0];
}

$tree = buildTree($items);

Upvotes: 1

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