PHP Array sorting by parent

Question

I got a complex array to be sorted, it looks like this:

Array
(
    [0] => Array
        (
            [id] => 1171409310
            [parent] => 1171287657
            [createdAt] => 2013-12-20T12:42:19
        )

    [1] => Array
        (
            [id] => 1171360372
            [parent] => 1171313704
            [createdAt] => 2013-12-20T11:18:46
        )

    [2] => Array
        (
            [id] => 1171313704
            [parent] => 1171304353
            [createdAt] => 2013-12-20T10:14:46
        )

    [3] => Array
        (
            [id] => 1171304353
            [parent] => 1171287657
            [createdAt] => 2013-12-20T09:55:34
        )

    [4] => Array
        (
            [id] => 1171303539
            [parent] => 1171014482
            [createdAt] => 2013-12-20T09:53:54
        )

    [5] => Array
        (
            [id] => 1171287657
            [parent] => 1170597579
            [createdAt] => 2013-12-20T09:29:34
        )

    [6] => Array
        (
            [id] => 1171264520
            [parent] => 1169354287
            [createdAt] => 2013-12-20T08:58:26
        )

    [7] => Array
        (
            [id] => 1171014482
            [parent] => 
            [createdAt] => 2013-12-20T02:51:24
        )

    [8] => Array
        (
            [id] => 1170700661
            [parent] => 1170597579
            [createdAt] => 2013-12-19T21:30:31
        )

    [9] => Array
        (
            [id] => 1170597579
            [parent] => 
            [createdAt] => 2013-12-19T20:22:40
        )

    [10] => Array
        (
            [id] => 1169362457
            [parent] => 
            [createdAt] => 2013-12-18T22:27:28
        )

    [11] => Array
        (
            [id] => 1169354287
            [parent] => 
            [createdAt] => 2013-12-18T22:20:08
        )

    [12] => Array
        (
            [id] => 1169315244
            [parent] => 
            [createdAt] => 2013-12-18T21:52:59
        )

)

I want the array to be first sorted by date (oldest on the top) and then each child after its parent (oldest on the top as well). The problem is that children can also be parents who have children as well so there are multiple dimensions. If possible I want also add the dimension.

I hope that my problem is clear.

EDIT: I get the array from the disqus API and want it to be sorted like it is on a website.

EDIT: It has to end like this:

Array
(
    [12] => Array
        (
            [id] => 1169315244
            [parent] => 
            [createdAt] => 2013-12-18T21:52:59
        )

    [11] => Array
        (
            [id] => 1169354287
            [parent] => 
            [createdAt] => 2013-12-18T22:20:08
        )

    [6] => Array
        (
            [id] => 1171264520
            [parent] => 1169354287
            [createdAt] => 2013-12-20T08:58:26
        )

    [10] => Array
        (
            [id] => 1169362457
            [parent] => 
            [createdAt] => 2013-12-18T22:27:28
        )

    [9] => Array
        (
            [id] => 1170597579
            [parent] => 
            [createdAt] => 2013-12-19T20:22:40
        )

    [8] => Array
        (
            [id] => 1170700661
            [parent] => 1170597579
            [createdAt] => 2013-12-19T21:30:31
        )

    [5] => Array
        (
            [id] => 1171287657
            [parent] => 1170597579
            [createdAt] => 2013-12-20T09:29:34
        )

    [3] => Array
        (
            [id] => 1171304353
            [parent] => 1171287657
            [createdAt] => 2013-12-20T09:55:34
        )

    [2] => Array
        (
            [id] => 1171313704
            [parent] => 1171304353
            [createdAt] => 2013-12-20T10:14:46
        )

    [1] => Array
        (
            [id] => 1171360372
            [parent] => 1171313704
            [createdAt] => 2013-12-20T11:18:46
        )

    [0] => Array
        (
            [id] => 1171409310
            [parent] => 1171287657
            [createdAt] => 2013-12-20T12:42:19
        )

    [7] => Array
        (
            [id] => 1171014482
            [parent] => 
            [createdAt] => 2013-12-20T02:51:24
        )


    [4] => Array
        (
            [id] => 1171303539
            [parent] => 1171014482
            [createdAt] => 2013-12-20T09:53:54
        )

)

Amelia · Accepted Answer · 2013-12-22 16:42:21Z

3

I'm building a comment system myself, currently. Just ordering the comments like this is not going to really give you a strong relationship between comments (a parent-child relationship).

In this case, I'd do the following:

$comments = array();
foreach ($results as $result) {
    if ($result["parent"]) {
        $result["children"] = array();
        $comments[$result["id"]] = $result;
    }
}

// Have yet to do this a better way. Second loop is there for a reason.
foreach ($results as $result) {
    if ($result["parent"])
        $comments[$result["parent"]]["children"] = $result;
}

var_dump($comments);
// you can now sort on createdAt using uasort(array $array, callable $func)

uasort($comments, function ($a, $b) {
    if ($a["createdAt"] == $b["createdAt"])
        return 0;
    return ($a["createdAt"] > $b["createdAt"]) ? 1 : -1;
    // reverse this to change sort order
});

edited Dec 22, 2013 at 16:42

answered Dec 22, 2013 at 13:42

Amelia

2,9712 gold badges27 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Amelia Over a year ago

@oskar and they will be deemed equal since null == null. also i didnt finish reading the question. adding the other sort

Amelia Over a year ago

@oskar you're relying on a loose relationship to have a comment hierarchy. I'm currently doing a comment system in PHP myself, so I'll just show you how I've done it.

Oskar Over a year ago

yeah, i am trying to integrate disqus into an app, unfortunately the order is still not right...

Oskar · Accepted Answer · 2013-12-22 17:51:04Z

2

uasort($array, function($a, $b) {   
    // sort by date first
    if (@$a["createdAt"] == @$b["createdAt"]){
        return 0;
    }
    return (@$a["createdAt"] > @$b["createdAt"]) ? 1 : -1;
});
$array_asc = array();
foreach($array as $key => $val){ 
    // create an array with ids as keys and children
    // with the assumption that parents are created earlier. 
    // store the original key
    $array_asc[$val['id']] = array_merge($val, array('org_key' => $key)); 
    if ($val['parent']){
        $array_asc[$val['parent']]['children'][] = $val['id'];
    }
}
$array_out = array();

// get a flat array again

foreach($array_asc as $val){
    if ($val['parent']){
        continue;         
    }
    add_to_output($array_out, $val, $array_asc);
}

function add_to_output(&$array_out, $val, $array_asc){ 
    $array_out[$val['org_key']] = $val;
    if (sizeof($val['children'])){
        foreach($val['children'] as $id){
            add_to_output($array_out, $array_asc[$id], $array_asc);
        }
    }
    unset($array_out[$val['org_key']]['children'], $array_out[$val['org_key']]['org_key']);
}

not tested.

edited Dec 22, 2013 at 17:51

Oskar

3294 silver badges15 bronze badges

answered Dec 22, 2013 at 17:20

martti

2,0851 gold badge15 silver badges10 bronze badges

1 Comment

Oskar Over a year ago

after correcting some syntax errors its working perfectly, thanks!!

user3127197 · Accepted Answer · 2013-12-22 13:43:52Z

1

you can user the php array_multisort

you probably want to build your array like this

<?php
function array_orderby()
{
    $args = func_get_args();
    $data = array_shift($args);
    foreach ($args as $n => $field) {
        if (is_string($field)) {
            $tmp = array();
            foreach ($data as $key => $row)
                $tmp[$key] = $row[$field];
            $args[$n] = $tmp;
            }
    }
    $args[] = &$data;
    call_user_func_array('array_multisort', $args);
    return array_pop($args);
}
?>


<?php
$data[] = array('createdAt' => 67, 'parent' => 2);
$data[] = array('createdAt' => 86, 'parent' => 1);
$data[] = array('createdAt' => 85, 'parent' => 6);
$data[] = array('createdAt' => 98, 'parent' => 2);
$data[] = array('createdAt' => 86, 'parent' => 6);
$data[] = array('createdAt' => 67, 'parent' => 7);

// Pass the array, followed by the column names and sort flags
$sorted = array_orderby($name_of_array, 'createdAt', SORT_DESC, 'parent', SORT_ASC);
?>

edited Dec 22, 2013 at 13:43

answered Dec 22, 2013 at 13:38

user3127197

196 bronze badges

6 Comments

Oskar Over a year ago

I receive the array from the disqus API and want to sort it like its sorted on a website.

user3127197 Over a year ago

@Oskar This will work to sort your array, i just tried it. I don't know why you are voting down on this

Amelia Over a year ago

It's a horribly complicated answer to sorting a simple array (that array is by no means complicated).

user3127197 Over a year ago

but it works and that code can be reuse to sort any array that he/she has. instead of creating a new function for each array.

user3127197 Over a year ago

What is the order that you are getting now?

|

Collectives™ on Stack Overflow

PHP Array sorting by parent

3 Answers 3

3 Comments

1 Comment

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

1 Comment

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related