By telling Symfony that the getUserAction() argument is a User instance, it will take for granted that the {id} url parameter must be matched to the as primary key, handing it over to the Doctrine ParamConverter to fetch the corresponding User.
There are at least two workarounds.
1. Use the ParamConverter repository_method config
In the controller function's comment, we can add the @ParamConverter annotation and tell it to use the repository_method option.
This way Symfony will hand the url parameter to a function in our entity repository, from which we'll be able to check the integrity of the url parameter.
In UserRepository, let's create a function getting an entity by primary key, checking first the integrity of the argument. That is, $id must not be larger than the largest integer that PHP can handle (the PHP_INT_MAX constant).
Please note: $id is a string, so it's safe to compare it to PHP_INT_MAX, because PHP will automatically typecast PHP_INT_MAX to a string and compare it to $id. If it were an integer, the test would always fail (by design, all integers are less than or equal to PHP_INT_MAX).
// ...
use Symfony\Component\Form\Exception\OutOfBoundsException;
class UserRepository extends ...
{
// ...
public function findSafeById($id) {
if ($id > PHP_INT_MAX) {
throw new OutOfBoundsException($id . " is too large to fit in an integer");
}
return $this->find($id);
}
}
This is only an example: we can do anything we like before throwing the exception (for example logging the failed attempt).
Then, in our controller, let's include the ParamConverter annotation:
use Sensio\Bundle\FrameworkExtraBundle\Configuration\ParamConverter;
and modify the function comment adding the annotation:
@ParamConverter("id", class="App:User", options={"repository_method" = "findSafeById"})
Our controller function should look like:
/**
* @Get("users/{id}")
* @ParamConverter("id", class="App:User", options={"repository_method" = "findSafeById"})
*/
public function getUserAction(User $user) {
// Return a "OK" response with the content you like
}
This technique allows customizing the exception, but does not give you control over the response - you'll still get a 500 error in production.
Documentation: see here.
2. Parse the route "the old way"
This way was the only viable one up to Symfony 3, and gives you a more fine-grained control over the generated response.
Let's change the action prototype like this:
/**
* @Route\Get("users/{id}", requirements={"id" = "(\d+)"})
*/
public function getUserAction($id)
{
}
Now, in the action we'll receive the requested $id and we'll be able to check whether it's ok. If not, we throw an exception and/or return some error response (we can choose the HTTP status code, the format and anything else).
Below you find a sample implementation of this procedure.
use FOS\RestBundle\Controller\Annotations\Get;
use FOS\RestBundle\Controller\FOSRestController;
use Symfony\Component\Form\Exception\OutOfBoundsException;
use Symfony\Component\HttpFoundation\JsonResponse;
class MyRestController extends FOSRestController {
/**
* @Get("users/{id}", requirements={"id" = "(\d+)"})
*/
public function getUserAction($id) {
try {
if ($id > PHP_INT_MAX) {
throw new OutOfBoundsException($id . " is too large to fit in an integer");
}
// Replace App\Entity\User with your actual Entity alias
$user = $this->getDoctrine()->getRepository('App\Entity\User')->find($id);
if (!$user) {
throw new \Doctrine\ORM\NoResultException("User not found");
}
// Return a "OK" response with the content you like
return new JsonResponse(['key' => 123]);
} catch (Exception $e) {
return new JsonResponse(['message' => $e->getMessage()], 400);
}
}