Symfony2 $ request-> request为空

I have a page with two forms that can be submitted separately. I tried this approach to check which form was submitted, but $request->request is always an empty array. What am I missing?

public function submitAction(Request $request) {
        $dm = $this->get('doctrine_mongodb')->getManager();
        $processes = $dm->getRepository('MyCoreBundle:Process')->findAll();

        $formClients = $this->createForm(new FiltersFormType(), $processes);
        $formClients->handleRequest($request);

        $formSuppliers = $this->createForm(new SupplierFormType(), $processes);
        $formSuppliers->handleRequest($request);
}

Edit: it's being posted via GET

Here's how I solved it, to check if a key is present, when posting via GET:

$request->query->get($formClients->getName())

you can try something like:

public function submitAction() {

    $request = $this->container->get('request');

    (...)

}