Group by on nested laravel collection

Question

I have started working on some data analyising, and the data is really messy, so i have to convert timestamps to readable date and time and such..

I have tried standard group by but it was not successful because the array is nested and i have no idea how to approach.

 Illuminate\Support\Collection Object
   (
    [items:protected] => Array
        (
        [0] => Array
            (
                [name] => Entity 1
                [values] => Array
                    (
                        [0] => Array
                            (
                                [date] => 08.07.2019
                                [time] => 00:00
                                [counter] => 1
                            )

                        [1] => Array
                            (
                                [date] => 08.07.2019
                                [time] => 01:00
                                [counter] => 3
                            )

                        [167] => Array
                            (
                                [date] => 14.07.2019
                                [time] => 23:00
                                [counter] => 0
                            )

                    )

            )
        [1] => Array
            (
                [name] => Entity 2
                [values] => Array
                    (
                        [0] => Array
                            (
                                [date] => 08.07.2019
                                [time] => 00:00
                                [counter] => 0
                            )

                        [1] => Array
                            (
                                [date] => 08.07.2019
                                [time] => 01:00
                                [counter] => 4
                            )

                        [2] => Array
                            (
                                [date] => 08.07.2019
                                [time] => 02:00
                                [counter] => 12
                            )

                        [3] => Array
                            (
                                [date] => 09.07.2019
                                [time] => 03:00
                                [counter] => 0
                            )

                        [4] => Array
                            (
                                [date] => 10.07.2019
                                [time] => 04:00
                                [counter] => 4
                            )

                        [5] => Array
                            (
                                [date] => 11.07.2019
                                [time] => 05:00
                                [counter] => 17
                            )

                    )

            )

So what would be the correct way to group this by date so i could get one array for one date for example

date 08.07: time: 02:00 counter: 12

timer: 04:00
counter: 1

date 14.07: time: 05:00 counter: 1

time: 08:00
counter: 3

time: 01:00
counter: 6

Sorry for dump example of an array

I have tried something like:

$collection = collect($values);
$groupedBy = $collection->groupBy('date);

But that just doesn't work since it's a nested array.

Answer 1

Before grouping you could reduce the collection in order to have only the items' values. After that you can simply use group by date and time:

$grouped = $collection
    ->reduce(function(Collection $carry, $item) {
        return $carry->merge($item['values']);
    }, new Collection())
    ->groupBy(function($item) {
        return sprintf('%s %s', $item['date'], $item['time']);
    });

where Collection is the imported Illuminate\\Support\\Collection