Can't guess how to get a Doctrine instance - php

Question

In a symfony projects, I'm trying to persist a line of an association table (profil_role) composed of two objects (profil and role).
First, I developed The create action in the ProfilRoleController of the second project this way:
/** #var Roles $role */
$em = $this->getDoctrine()->getManager('main_project');
$role = $em->getRepository("MyBundle\Entity\Roles")->find($roleId);
$profil = $em->getRepository("MyBundle\Entity\Profil")->find($profilId);
$profilRole = new ProfilRoles();
$profilRole->setRoleId($role->getId());
$profilRole->setProfilId($profil->getId());
$em->persist($profilRole);
$em->flush();
This part of code, call then the post entity action present in the main project:
/**
* #Rest\View(statusCode=Response::HTTP_CREATED)
* #Rest\Post("/profil_roles")
*/
public function postEntityAction(ProfilRoles $profilRole)
{
$em = $this->getDoctrine()->getManager();
$em->persist($profilRole);
$em->flush();
return $profilRole;
}
When I try to execute my code i'm getting this king of error:
Execution failed for request: POST /api/profil_roles? HTTP/1.1 {"profil":{"id":"12"},"role":{"id":"3"}}: HTTPCode 500, body {"code":500,"message":"Unable to guess how to get a Doctrine instance from the request information."}
I've tried to use the #ParamConverter annotation, but I don't how to use it my case.

Answer 1

try this:
public function postEntityAction() {
$postData = $request->request->all();
$profileRole = $postData['profile_role']
Instead of this:
public function postEntityAction(ProfilRoles $profilRole)

Answer 2

#AlessandroMinoccheri I've tried to be inspired by your reply to do this and i'ts workin, i don't know if it's the correct way.
/**
* #param ProfilRoles $profilRole
* #param Request $request
* #return ProfilRoles
* #Rest\View(statusCode=Response::HTTP_CREATED)
* #Rest\Post("/profil_roles")
*/
public function postEntityAction(Request $request)
{
$profilRole = new ProfilRoles();
$em = $this->getDoctrine()->getManager();
$requete = $request->request->all();
$profilRole->setProfilId($requete['profil']['id']);
$profilRole->setRoleId($requete['role']['id']);
$em->persist($profilRole);
$em->flush();
return $profilRole;
}