JhumanJ/OpnForm

use Illuminate\Contracts\Validation\Rule;

class OneEmailPerLine implements Rule
{
    public function passes($attribute, $value)
    {
        if ($value === null || empty(trim($value))) return true;
        foreach (preg_split("/\r\n|\n|\r/", $value) as $email) {
            $email = trim($email);
            if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
                return false;
            }
        }
        return true;
    }

    public function message()
    {
        return 'You need one valid email per line.';
    }
}

use App\Models\Forms\Form;
use App\Rules\OneEmailPerLine;
use Illuminate\Validation\Rule;
use App\Rules\FormPropertyLogicRule;

abstract class UserFormRequest extends \Illuminate\Foundation\Http\FormRequest
{
    public function rules()
    {
        return [
            //
            'notification_emails' => ['required_if:notifies,1', new OneEmailPerLine ],
            //
        ];
    }
    //
}