How to use decrement in Laravel 5.2 using data from an array?

Question

I’m using the Larable a few months ago and I came across the following problem of controlling stock after purchase automatically.

The logic of my system is this::

After purchasing a product in my store automatically decrease the amount selected by the user at the time of purchase, the system works correctly when there is only one item in the cart, when there are two items or more the system changes only one, my doubt is as it gets the code to recover and manipulate all the items through an array, follows the code:

php.blade.

@foreach($produtos as $produto)
 ...
Os valores a seguir estão dentro de um input, que são enviados por um formulário (acrescentei as [] em ambos).

    <input type="hidden" name="id[]" value="{{ $produto['item']['id'] }}">
    <input type="hidden" name="qtde[]" value="{{ $produto['quantidade'] }}">
...
@endforeach

Meucontroller.php my doubt is still in this file, I altered and it’s like this:

public function funcao(Request $request)
{

DB::table('produtos')
    ->where(['id', $request->get('id')])
    ->decrement(['quantidade', $request->get('qtde')]);

}

and as already expected returned the following error:

strtolower() expects Parameter 1 to be string, array Given

Answer 1

The ids and quantities will already be a server-side array, What you have to do afterwards when you receive the data in your controller is:

...
foreach($request->get('id') as $key => $id) {
    if(isset($request->get('qtde')[$key]) && is_numeric($request->get('qtde')[$key])) {
        DB::table('produtos')
        ->where('id', $id)
        ->decrement('quantidade', $request->get('qtde')[$key]);
    }
}
...