Difference between getMethod() and getRealMethod() in Symphony5 - php

Question

I am not able to understand the difference between getMethod() and getRealMethod() in Symphony5.
I am using:
Symfony 5
PHP 7.4.3
I have already read through this StackOverflow post, but I am still facing strange issues.
What I want to achieve: Currently if I give an empty body to a
POST/PUT request then symfony gives a 500 Internal Server Error. But,
I want to give a 400 Bad Request Error to the user along with a custom
error message like "Empty request body with PUT/POST not allowed"
I have created this Request Listener,
namespace App\EventListener;
use Exception;
use Symfony\Component\HttpKernel\Event\RequestEvent;
use Psr\Log\LoggerInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\JsonResponse;
class RequestListener
{
/**
* #var LoggerInterface $logger
*/
private $logger;
public function __construct(LoggerInterface $logger)
{
$this->logger = $logger;
}
public function __invoke(RequestEvent $event): ?Response
{
$request = $event->getRequest();
$method = $request->getMethod();
$realMethod = $request->getRealMethod();
// this echo below is just to know the values for $method and $realMethod for debugging
echo("method = $method and real method = $realMethod");
if (in_array($method, [Request::METHOD_POST, Request::METHOD_PUT]) && $request->get('data') === null) {
$this->logger->info("Method PUT/POST with an empty body");
return new Response(null, Response::HTTP_BAD_REQUEST);
}
}
}
I have also added this Request Listener to the services.yaml file as,
App\EventListener\RequestListener:
tags:
- { name: kernel.event_listener }
Now when I try to test this with postman I have the following response,
as you can see, the method I used is clearly shown as POST, symfony returns it as GET both for getMethod() and getRealMethod() (by the way, I am not sure why I get the echo message "method = GET and real method = GET" twice). And thus I am not able to check for the empty body for POST/PUT.
EDITED:
Running bin/console debug:event-dispatcher gives this output:
"kernel.request" event
----------------------
------- ---------------------------------------------------------------------------------------------- ----------
Order Callable Priority
------- ---------------------------------------------------------------------------------------------- ----------
#1 Symfony\Component\HttpKernel\EventListener\DebugHandlersListener::configure() 2048
#2 Symfony\Component\HttpKernel\EventListener\ValidateRequestListener::onKernelRequest() 256
#3 Nelmio\CorsBundle\EventListener\CorsListener::onKernelRequest() 250
#4 Symfony\Component\HttpKernel\EventListener\SessionListener::onKernelRequest() 128
#5 Symfony\Component\HttpKernel\EventListener\LocaleListener::setDefaultLocale() 100
#6 Symfony\Component\HttpKernel\EventListener\RouterListener::onKernelRequest() 32
#7 ApiPlatform\Core\EventListener\QueryParameterValidateListener::onKernelRequest() 16
#8 Symfony\Component\HttpKernel\EventListener\LocaleListener::onKernelRequest() 16
#9 Symfony\Component\HttpKernel\EventListener\LocaleAwareListener::onKernelRequest() 15
#10 Symfony\Bundle\SecurityBundle\Debug\TraceableFirewallListener::configureLogoutUrlGenerator() 8
#11 Symfony\Bundle\SecurityBundle\Debug\TraceableFirewallListener::onKernelRequest() 8
#12 ApiPlatform\Core\EventListener\AddFormatListener::onKernelRequest() 7
#13 ApiPlatform\Core\EventListener\ReadListener::onKernelRequest() 4
#14 ApiPlatform\Core\Security\EventListener\DenyAccessListener::onSecurity() 3
#15 ApiPlatform\Core\EventListener\DeserializeListener::onKernelRequest() 2
#16 ApiPlatform\Core\Security\EventListener\DenyAccessListener::onSecurityPostDenormalize() 1
#17 App\EventSubscriber\EmptyRequestBodySubscriber::handleEmptyRequestBody() 1
#18 App\EventListener\RequestListener::__invoke() 0
#19 ApiPlatform\Core\Bridge\Symfony\Bundle\EventListener\SwaggerUiListener::onKernelRequest() 0
------- ---------------------------------------------------------------------------------------------- ----------
As you can see, my listener is found registered at #18,
#18 App\EventListener\RequestListener::__invoke() 0