Callback Constraint doesn't show paylod (Symfony Validator Component) - symfony

Question

My controller code:
public function postFilesAction(Request $request)
{
$validator = $this->get('validator');
$requestCredentials = RequestCredentials::fromRequest($request);
$errors = $validator->validate($requestCredentials);
...
validate method in RequestCredentials (Callback constraint).
/**
* #Assert\Callback(payload = {"errorCode" = "FILE_FILE_URL"})
*/
public function validate(ExecutionContextInterface $context)
{
if (! ($this->fileExistsAndValid() || $this->fileUrlExistsAndValid())) {
$context->buildViolation('Neither file nor file_url is present.')->addViolation();
}
}
Callback works as expected, but the value of $constraintViolation->$constraint->$payload is null.
When I'm trying to use payload in other Constraints (NotBlank, for example), it works (I can see it in ConstraintViolation object).
Is it Symfony bug or am I doing somethings wrong? Should I use some other solution to my problem? (I need to check if there's at least one of two fields (file or file_url) present in request).

Answer 1

In Symfony 3.0 you cannot easily access the payload in the callback when using the Callback constraint. Starting with Symfony 3.1, the payload will be passed as an additional argument to the callback (see https://github.com/symfony/symfony/issues/15092 and https://github.com/symfony/symfony/pull/16909).

Answer 2

I managed to solve this problem with following code in the assertion:
/**
* #Assert\Callback(payload = {"error_code" = "1"}, callback = "validate", groups = {"Default", "RequestCredentials"})
*/
public function validate(ExecutionContextInterface $context)
{
// some validation code
}
I think the problem was because of the Symfony Callback constraint constructor:
public function __construct($options = null)
{
// Invocation through annotations with an array parameter only
if (is_array($options) && 1 === count($options) && isset($options['value'])) {
$options = $options['value'];
}
if (is_array($options) && !isset($options['callback']) && !isset($options['groups'])) {
$options = array('callback' => $options);
}
parent::__construct($options);
}
When it is given $options = ['payload' => [...]] (what happened in my case) it turns it into $options = ['callback' => ['payload' => [...]]]
and then '$payload' data becomes inacessable in ConstraintViolation object.
But I'm still not sure whether it's Symfony imperfection or me not getting something and using it wrong.