Symfony twig service user from token storage is null sometimes - symfony

Question

I have a service that I have defined as a global twig variable that makes use of autowiring the TokenStorageInterface in order to get the current logged in user.
Sometimes the token is null and throws an exception when trying to access a null object. Call to a member function getUser() on null
This is the barebone code that breaks.
BonusService.php
namespace AppBundle\Service;
use Doctrine\Common\Persistence\ObjectManager;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
class BonusService {
private $user;
private $manager;
__construct(TokenStorageInterface, $tokenStorage, ObjectManager $manager) {
$this->user = $tokenStorage->getToken()->getUser(); // Sometimes fails here
$this->manager = $manager;
}
public function hasBonuses() {
return count($this->manager->getRepository(Bonus::class)->findBy(array('contact' => $user)) > 0;
}
}
services.yml
services:
_defaults:
autowire: true
autoconfigure: true
public: true
AppBundle\Service\BonusService:
config.yml
twig:
...
globals:
bonus_service: '#AppBundle\Service\BonusService'
index.html.twig
...
{% if bonus_service.hasBonuses %}Have Bonuses{% endif %}
...
I've been googling reasons as to why the token storage may be null when twig is doing it's thing. One issue predominately came appeared is to assure that my route is behind a firewall, which in this case it is and requires an authenticated user.
Also with noting is that I have a similar service with an identical constructor which is utilised within a controller. When the BonusService doesn't decide to use a null token and the page loads, the other service has no problem grabbing a token. When I remove the call to the service in twig, the page loads 100% of the time, even with the other service and it's identical constructor.
Any help would be much appreciated!

Answer 1

When creating services your constructor should avoid executing much beyond storing the injected services as a reference.
class BonusService {
private $tokenStorage;
private $manager;
public function __construct(TokenStorageInterface $tokenStorage, ObjectManager $manager) {
$this->tokenStorage = $tokenStorage;
$this->manager = $manager;
}
public function hasBonuses() {
if (!$this-tokenStorage->getToken() instanceof User) {
return false;
}
return count($this->manager->getRepository(Bonus::class)->findBy(array(
'contact' => $this-tokenStorage->getToken()->getUser())
) > 0;
}
}
You still have to check if the token is set and is an instance of User (or however your User is called).
The reason you should not use any of the injected services at in the constructor is because at that stage the container is still booting up and building all the services. So your dependencies might not yet be initialized fully.