cssd-back/app/Http/Requests/StoreItemRequest.php

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class StoreItemRequest extends FormRequest
{
    public function authorize()
    {
        if ($this->method() == 'POST') {
            return true;
        } else {
            $Item = $this->route('Item');
            return auth('api')->check() && $Item && auth('api')->user()->can('update', $Item);
        }
    }

    public function rules()
    {
        switch ($this->method()) {
            case 'POST': {
                return [
                    'name' => 'required|max:100',
                    'unique_id' => 'nullable|max:100|unique:items',
                    'size' => 'required',
                    'specific' => 'required',
                    'note' => 'nullable',
                    'udi' => 'required|max:100|unique:items',
                ];
                break;
            }
            case 'PUT':
            case 'PATCH': {
                $Item =  $this->route('Item');
                return [
                    'name' => 'required|max:100',
                    'unique_id' => 'nullable|max:100|unique:items,unique_id,'.$Item->id,
                    'size' => 'required',
                    'specific' => 'required',
                    'note' => 'nullable',
                    'udi' => 'required|max:100|unique:items,udi,'.$Item->id,
                ];
                break;
            }
            default:
                break;
        }

    }

}