<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\Security\Core\Authorization\Voter;
use Symfony\Component\ExpressionLanguage\Expression;
use Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Security\Core\Authentication\AuthenticationTrustResolverInterface;
use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Authorization\ExpressionLanguage;
use Symfony\Component\Security\Core\Role\RoleHierarchyInterface;
/**
* ExpressionVoter votes based on the evaluation of an expression.
*
* @author Fabien Potencier <fabien@symfony.com>
*/
class ExpressionVoter implements VoterInterface
{
private $expressionLanguage;
private $trustResolver;
private $roleHierarchy;
public function __construct(ExpressionLanguage $expressionLanguage, AuthenticationTrustResolverInterface $trustResolver, RoleHierarchyInterface $roleHierarchy = null)
{
$this->expressionLanguage = $expressionLanguage;
$this->trustResolver = $trustResolver;
$this->roleHierarchy = $roleHierarchy;
}
public function addExpressionLanguageProvider(ExpressionFunctionProviderInterface $provider)
{
$this->expressionLanguage->registerProvider($provider);
}
/**
* {@inheritdoc}
*/
public function vote(TokenInterface $token, $subject, array $attributes)
{
$result = VoterInterface::ACCESS_ABSTAIN;
$variables = null;
foreach ($attributes as $attribute) {
if (!$attribute instanceof Expression) {
continue;
}
if (null === $variables) {
$variables = $this->getVariables($token, $subject);
}
$result = VoterInterface::ACCESS_DENIED;
if ($this->expressionLanguage->evaluate($attribute, $variables)) {
return VoterInterface::ACCESS_GRANTED;
}
}
return $result;
}
private function getVariables(TokenInterface $token, $subject)
{
if (null !== $this->roleHierarchy) {
$roles = $this->roleHierarchy->getReachableRoles($token->getRoles());
} else {
$roles = $token->getRoles();
}
$variables = [
'token' => $token,
'user' => $token->getUser(),
'object' => $subject,
'subject' => $subject,
'roles' => array_map(function ($role) { return $role->getRole(); }, $roles),
'trust_resolver' => $this->trustResolver,
];
// this is mainly to propose a better experience when the expression is used
// in an access control rule, as the developer does not know that it's going
// to be handled by this voter
if ($subject instanceof Request) {
$variables['request'] = $subject;
}
return $variables;
}
}