Codeigniter4でカスタムバリデーションの作り方

codeigniter4.14

app/Config/Validation.php
次の通り　CustomRules::class　を追加
----
    public $ruleSets = [
        Rules::class,
        FormatRules::class,
        FileRules::class,
        CreditCardRules::class,
	CustomRules::class
    ];

app/Config/CustomRules.php
----
<?php
namespace Config;
class CustomRules
{
	public function even(string $str, string &$error = null): bool
	{
		if ((int) $str % 2 !== 0) {
			$error = lang('myerrors.evenError');
			return false;
		}
		return true;
	}
}
?>

validation rule に　even が使えるようになった
$validation->setRules(
		'hogehoge' => ['label' => 'hogehoge','rules' => 'even']
);