Simple in-place validation in Symfony2

symfony2-simple-in-place-validation-example.php

<?php

$data = array(
    'agency' => array(
        'name' => 'a',
        'moderator' => 'b'
    )
);

$rules = new Symfony\Component\Validator\Constraints\Collection(array(
    'fields' => array(
        'agency' => array(
            new Symfony\Component\Validator\Constraints\Collection(array(
                'fields' => array(
                    'name' => array(
                        new Symfony\Component\Validator\Constraints\NotBlank()
                    ),
                    'moderator' => array(
                        new Symfony\Component\Validator\Constraints\NotBlank()
                    ),
                )
            ))
        )
    )
));

// @see http://api.symfony.com/2.1/Symfony/Component/Validator/ConstraintViolationList.html
$violationList = $container->get('validator')->validateValue($data, $rules);

if (count($violationList))
    echo $violationList; // gracefully casts to string