Laravelのselectフォームでoption hiddenを利用した時のvalidationについての忘備録

//省略

//都道府県データ
//$prefs =['北海道','青森県','岩手県'・・・・];

  <select name="pref" required>
    <option hidden>都道府県</option>
    @foreach ($prefs as $pref)
      <option value="{{ $pref }}" selected>{{ $pref }}</option>
    @endforeach
  </select>

php artisan make:request CorpRequest

<?php

namespace App\Http\Requests;

use Illuminate\Foundation\Http\FormRequest;

class CorpRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;//※trueに変更
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'pref' => 'prohibited_if:pref,null',
        ];
    }

    public function messages()
    {
        return [
            'prohibited_if' => ':attributeを選択してください。',
        ];
    }
}

<?php
namespace App\Http\Controllers\User;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use App\Models\Corp;
use App\Http\Requests\CorpRequest;//クラスを読み込む

//省略

    public function store(CorpRequest $request)//RequestをCorpRequestに変更
    {
        Corp::create([
            'pref' => $request->pref,
//以下省略

//省略

//都道府県データ
//$prefs =['北海道','青森県','岩手県'・・・・];

  <select name="pref" required>
    <option value="null" hidden>都道府県</option> //valueに「null」を設定
    @foreach ($prefs as $pref)
      <option value="{{ $pref }}" selected>{{ $pref }}</option>
    @endforeach
  </select>