Symfony2: Call Voter from another Voter - symfony

Question

I am using Voters to restrict access to entities in a REST API.
Step 1
Consider this voter that restricts users access to blog posts:
class BlogPostVoter extends Voter
{
public function __construct(AccessDecisionManagerInterface $decisionManager)
{
$this->decisionManager = $decisionManager;
}
/**
* Determines if the attribute and subject are supported by this voter.
*
* #param string $attribute An attribute
* #param int $subject The subject to secure, e.g. an object the user wants to access or any other PHP type
*
* #return bool True if the attribute and subject are supported, false otherwise
*/
protected function supports($attribute, $subject)
{
if (!in_array($attribute, $this->allowedAttributes)) {
return false;
}
if (!$subject instanceof BlogPost) {
return false;
}
return true;
}
/**
* Perform a single access check operation on a given attribute, subject and token.
*
* #param string $attribute
* #param mixed $subject
* #param TokenInterface $token
* #return bool
* #throws \Exception
*/
protected function voteOnAttribute($attribute, $subject, TokenInterface $token)
{
return $this->canUserAccess($attribute, $subject, $token);
}
public function canUserAccess($attribute, $subject, TokenInterface $token) {
if ($this->decisionManager->decide($token, array('ROLE_SUPPORT', 'ROLE_ADMIN'))) {
return true;
}
//other logic here omitted ...
return false;
}
}
You can see there is a public function canUserAccess to determine if the user is allowed to see the BlogPost. This all works just fine.
Step 2
Now I have another voter that checks something else, but also needs to check this same exact logic for BlogPosts. My thought was to:
add a new voter
perform some other checks
but then also perform this BlogPost check
So I thought I would inject the BlogPostVoter into my other voter like this:
class SomeOtherVoter extends Voter
{
public function __construct(BlogPostVoter $blogPostVoter)
{
$this->decisionManager = $decisionManager;
}
...
protected function voteOnAttribute($attribute, $subject, TokenInterface $token)
{
//other logic
if ($this->blogPostVoter->canUserAccess($attribute, $subject, $token)) {
return true;
}
return false;
}
}
Problem
When I do this I get the following error, using both setter and constructor injection:
Circular reference detected for service "security.access.decision_manager", path: "security.access.decision_manager"
I don't see where the security.access.decision_manager should depend on the Voter implementations. So I'm not seeing where the circular reference is.
Is there another way I can call VoterA from VoterB?

Answer 1

To reference VoterOne from VoterTwo you can inject the AuthorizationCheckerInterface into VoterTwo and then call ->isGranted('ONE'). Where ONE is the supported attribute of VoterOne.
Like:
class VoterTwo extends Voter
{
private $authorizationChecker;
public function __construct(AuthorizationCheckerInterface $authorizationChecker)
{
$this->authorizationChecker = $authorizationChecker;
}
protected function supports($attribute, $subject)
{
return in_array($attribute, ['TWO']);
}
protected function voteOnAttribute($attribute, $subject, TokenInterface $token)
{
return $this->authorizationChecker->isGranted('ONE', $subject);
}
}
In this example VoterTwo does just redirect the request to VoterOne (or the voter that supports the attribute ONE). This can then be extended through additional conditions.