Validation#

Elang wraps Symfony Validator constraints. Rules are objects, so you can use the existing constraint ecosystem without another string-based rule language.

Validate a payload#

use Elang\Validation\Validator;
use Symfony\Component\Validator\Constraints as Assert;

$validated = $validator->validate($data, [
    'name' => [new Assert\NotBlank(), new Assert\Type('string'), new Assert\Length(min: 2, max: 80)],
    'email' => [new Assert\NotBlank(), new Assert\Type('string'), new Assert\Email()],
]);

Inject Validator into a handler or controller. A successful validation returns only fields listed in the rules. Unknown fields are not included in the returned array.

Required and optional fields#

Most constraints accept null or empty input. Add NotBlank or NotNull for required values. Use Type when the incoming type matters. Validation does not silently coerce input.

Error responses#

A failure throws ValidationException. The HTTP kernel returns status 422:

{
  "message": "The submitted data is invalid.",
  "errors": {"email": ["This value is not a valid email address."]},
  "request_id": "a request correlation identifier"
}

Form applications can catch the exception and render their own form errors. Constraint messages can be customized using Symfony's constraint options.