Show data per day with multiple tables?

This is one possibility:

public function show($id)
{
    $child = Child::find($id);

    // Define a Closure that will apply grouping to each Collection.
    $groupingFunction = function ($act) {
        return $act->created_at->toDateString();
    };

    // Apply grouping on each relation
    $groupedActone = $child->actone->groupBy($groupingFunction);
    $groupedActtwo = $child->acttwo->groupBy($groupingFunction);
    $groupedActthree = $child->actthree->groupBy($groupingFunction);

    return view('admin.children.show'(compact('child', 'groupedActone', 'groupedActtwo', 'groupedActthree'));
}

In the view you have each Act grouped by date, so you need nested loops

@foreach ($groupedActone as $date => $actones): ?>
    {{ $date }}
    @foreach($actones as $actone)
        <tr>
            <td>{{$actone->category}}</td>
            <td>{{$actone->time}}</td>
            <td>{{$actone->name}}</td>
            <td>{{$actone->rating}}</td>
            <td>{{$actone->comment}}</td>
            <td>{{$actone->created_at}}</td>
        </tr>
    @endforeach
@endforeach

@tykus Getting error.. toDateFormat does not work.. http://prntscr.com/j6hgs4

Silly me.. should be. toDateString() - updated above for accuracy

@tykus It kinda worked... but this is what im getting in my view: https://prnt.sc/j6hp23

So it sorts well on data, but if the date of actone is the same as acttwo, it doesn't show under the same label.. Do you know how to change it?

I tried to add the acttwo like this:

@foreach ($groupedActone as $date => $actones)
    <br>
    {{ $date }}
    <br>


    @foreach($actones as $actone)
    <strong>eten</strong>
        <tr>
            <td>{{$actone->category}}</td>
            <td>{{$actone->time}}</td>
            <td>{{$actone->name}}</td>
            <td>{{$actone->rating}}</td>
            <td>{{$actone->comment}}</td>
        </tr>
    @endforeach


@endforeach


@foreach ($groupedActtwo as $date => $acttwos)
  <br>
    {{ $date }}
  <br>

    @foreach($acttwos as $acttwo)
    <strong>slapen</strong>
        <tr>
            <td>{{$actone->category}}</td>
            <td>{{$actone->time}}</td>
            <td>{{$actone->name}}</td>
            <td>{{$actone->rating}}</td>
            <td>{{$actone->comment}}</td>
            <td>{{$actone->created_at}}</td>
        </tr>
    @endforeach


@endforeach 

Ok, I misunderstood your requirement in that case; do you want all of the actone, acttwo and actthree grouped under the same date? Do they all have the same properties, or different?

@tykus Im sorry.. so yeah I want all the actone, acttwo and actthree under the same date. They have different properties

@tykus Could you please take another look at this please? Your solutions seem to work very wel.. thanks

@Ibe if you merge the three collections before grouping, then you would have one collection to pass to the view:

public function show($id)
{
    $child = Child::find($id);

    // Define a Closure that will apply grouping to each Collection.
    $groupingFunction = ;

    $allActs = $child->actone->toBase()
    ->merge($child->acttwo->toBase())
    ->merge($child->$actthree->toBase())
    ->groupBy(function ($act) {
            return $act->created_at->toDateString();
    });

    return view('admin.children.show'(compact('child', 'allActs'));
}

Then inside the view, you would need to check the Model before deciding what to output - one possibility would be to have a partial view created for each resources/views/acts/partials/ActOne.blade.php, resources/views/acts/partials/ActTwo.blade.php and resources/views/acts/partials/ActThree.blade.php, and include the partial dynamically depending on the current model in the loop:

@foreach ($allActs as $date => $acts)
    {{ $date }}
    @foreach($acts as $act)
    @php
        $viewName = (new ReflectionClass($act))->getShortName();
    @endphp

    @include("acts.partials.{$viewName}")
    @endforeach
@endforeach

@tykus Hi there, it kinda worked... So I tried it this way with partials, but the strange thing is that ALL acts get displayed under the date (and not only the ones that belongs to that date...)? I can't figure out why... http://prntscr.com/j6zc6c

So what I have:

The controller

public function show($id)
    {
      $child = Child::find($id);


      // Define a Closure that will apply grouping to each Collection.

   $allActs = $child->actone->toBase()
   ->merge($child->acttwo->toBase())
   ->merge($child->actthree->toBase())
   ->groupBy(function ($act) {
           return $act->created_at->toDateString();
   });

      $next = Child::where('id', '<', $child->id)->orderBy('id', 'desc')->first();
      $previous = Child::where('id', '>', $child->id)->first();
      return view('admin.children.show', compact('child', 'allActs'))->with('next', $next)->with('previous', $previous);
    }

show.blade.php:

@foreach ($allActs as $date => $acts)
<strong>{{ $date }}</strong>

    @foreach($acts as $act)
    @php
        $viewName = (new ReflectionClass($act))->getShortName();
    @endphp

    @include("admin.activities.partials.{$viewName}")
    @endforeach
@endforeach 

partials/actone.blade.php: (for each act)

<?php foreach ($child->actone as $actone): ?>
  <h1>ETEN</h1>

  <td>{{$actone->category}}</td>
  <td>{{$actone->time}}</td>
  <td>{{$actone->name}}</td>
  <td>{{$actone->rating}}</td>
  <td>{{$actone->comment}}</td>

<?php endforeach; ?>

What does the Collection look like after the merge and grouping?

@tykus How can I check this? (sorry im new..) But its difficult to explain what im getting in my view because I am confused of what data im getting back... But i'll give it a try: So I think that my data is looping 2x somewhere... -> If I start 'fresh' and add a new activity (lets say actone), it gets displayed under the correct date. But then when I add another actone, this gets displayed under the correct date, but then each acts gets displayed 2 times... Then this is what im getting in my view: http://prntscr.com/j73dca

@tykus Do you maybe have another solution? Im still struggling with this.. sorry :(