How to sync pivot with extra field in Laravel? - php

Question

I need some help about a problem in Laravel . I have 3 tables:
pellets
specie (there are the trees)
specie_pellet (this is the pivot table)
The specie_pellet table is a pivot for the composition of a pellet and has an extra field called percentuale (percentage).
Obviously the relation is belongsToMany in Specie Class and belongsToMany in Pellet Class
In detail Pellet Class:
// Imposto la relazione con le Specie
public function specie()
{
return $this->belongsToMany(Specie::class)->withPivot('percentuale');
}
In detail Specie Class:
// Imposto la relazione con i Pellets
public function pellets()
{
return $this->belongsToMany(Pellet::class)->withPivot('percentuale');
}
To modify the table i use a form:
{!! Form::model($pellet, ['method' => 'PUT', 'route' => ['composizione.update', $pellet->id]]) !!}
<table class="table table-bordered">
<thead>
<th>Specie</th>
<th>Percentuale</th>
<th>Azione</th>
</thead>
<tbody>
#foreach($pellet->specie as $specie)
<tr>
<td>{!! Form::select('specie[]', $listaSpecie, $specie->id, ['class' => 'form-control']) !!}</td>
<td>
<input type="text" class="form-control" name="percentuale[]" value="{{ $specie->pivot->percentuale }}">
</td>
<td><a class="btn btn-danger" href="{{ url('composizione/pellet/elimina/id/' . $pellet->id . '/specie/' . $specie->id) }}">Elimina</a> </td>
</tr>
#endforeach
</tbody>
</table>
{!! Form::submit('Aggiorna Composizione', ['class' => 'btn btn-success']) !!}
{!! Form::close() !!}
the request pass to the route
Route::put('composizione/pellet/update/{id}', 'PelletController#updateComposizione')->name('composizione.update');
And finally I have the controller
public function updateComposizione(\App\Http\Requests\ComposizioneUpdateRequest $request, $id)
{
$pellet = Pellet::find($id);
$specie = Input::get('specie');
$percentuali = Input::get('percentuale');
$pellet->specie()->sync([$specie => ['percentuale' => $percentuali]]);
return redirect('admin/pellets/')->with('ok_success', 'Composizione aggiornata correttamente');
}
But I get this error: Illegal offset type
in PelletController.php line 94
at HandleExceptions->handleError(2, 'Illegal offset type', '/srv/users/serverpilot/apps/laraweb/app/Http/Controllers/PelletController.php', 94, array('request' => object(ComposizioneUpdateRequest), 'id' => '5', 'pellet' => object(Pellet), 'specie' => array('1', '7'), 'percentuali' => array('50', '50'))) in PelletController.php line 94
at PelletController->updateComposizione(object(ComposizioneUpdateRequest), '5')
at call_user_func_array(array(object(PelletController), 'updateComposizione'), array(object(ComposizioneUpdateRequest), 'id' => '5')) in Controller.php line 55
...
Can someone help me understand this please?
Thanks a lot and sorry for my english. I'm Italian ;)

Answer 1

I would suggest you review the laravel tutorials on forms and rethink this approach, namely the select may not be the best way to do this. The select is not the best way to solve this one.
Try doing this:
#foreach($pellet->specie as $specie)
{!! Form::open(["url" => "composizione/pellet/update/".$pellet->id, "method" => "PUT"]) !!}
<tr>
<td>
<input type="hidden" name="specie" value={{$specie->id}} />
<input type="text" class="form-control" name="percentuale" value="{{ $specie->pivot->percentuale }}">
</td>
<td><inpyt type="submit" class="btn btn-danger">Elimina</a> </td>
</tr>
{!! Form::close() !}}
#endforeach
The rest would probably work. What's happening here is you're going to update a single specie / percentuale combination at once, not multiple ones.