use Yiisoft\Validator\Result;
use Yiisoft\Validator\Rule\RuleHandlerInterface;
use Yiisoft\Validator\ValidationContext;
use Yiisoft\Validator\Rule\Handler\Container\RuleHandlerContainer;

/**
 * Validates that the value is a Pi.
 */
final class PiHandler implements RuleHandlerInterface
{
    public function validate(mixed $value, object $rule, ?ValidationContext $context = null): Result
    {
        $result = new Result();

        if (!(\abs($value - M_PI) < PHP_FLOAT_EPSILON)) {
            $result->addError('Value must be Pi.', ['value' => $value]);
        }

        return $result;
    }
}

$ruleHandlerContainer = new RuleHandlerContainer(new MyContainer());
$ruleHandler = $ruleHandlerContainer->resolve(PiHandler::class);

$ruleHandler = $ruleHandlerContainer->create(PiHandler::class); // Returned from cache

use Yiisoft\Di\Container;
use Yiisoft\Di\ContainerConfig;
use Yiisoft\Validator\RuleHandlerResolverInterface;
use Yiisoft\Validator\Rule\Handler\Container\RuleHandlerContainer;

// Need to be defined in params.php
$params = [
    'yiisoft/validator-rule-handler-container' => [
        'handlers' => [PiHandler::class => PiHandler::class],
        'validate' => true,
    ],
];

// Need to be defined in common.php
$config = [
    RuleHandlerResolverInterface::class => [
        'class' => RuleHandlerContainer::class,
        '__construct()' => [
            'definitions' => $params['yiisoft/validator-rule-handler-container']['handlers'],
            'validate' => $params['yiisoft/validator-rule-handler-container']['validate'],
        ],
    ]
];

$containerConfig = ContainerConfig::create()->withDefinitions($config); 
$container = new Container($containerConfig);
$ruleHandlerResolver = $container->get(RuleHandlerResolverInterface::class);        
$ruleHandler = $ruleHandlerResolver->resolve(PiHandler::class);