Using Expressions in Security Access Controls
See also
The best solution for handling complex authorization rules is to use the Voter System.
In addition to security roles like ROLE_ADMIN
, the isGranted()
method
and #[IsGranted]
attribute also accept an
Expression object:
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// src/Controller/MyController.php
namespace App\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\ExpressionLanguage\Expression;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Security\Http\Attribute\IsGranted;
class MyController extends AbstractController
{
#[IsGranted(new Expression('is_granted("ROLE_ADMIN") or is_granted("ROLE_MANAGER")'))]
public function show(): Response
{
// ...
}
#[IsGranted(new Expression(
'"ROLE_ADMIN" in role_names or (is_authenticated() and user.isSuperAdmin())'
))]
public function edit(): Response
{
// ...
}
}
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// src/Controller/MyController.php
namespace App\Controller;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\ExpressionLanguage\Expression;
use Symfony\Component\HttpFoundation\Response;
class MyController extends AbstractController
{
public function show(): Response
{
$this->denyAccessUnlessGranted(new Expression(
'is_granted("ROLE_ADMIN") or is_granted("ROLE_MANAGER")'
));
// ...
}
public function edit(): Response
{
$this->denyAccessUnlessGranted(new Expression(
'"ROLE_ADMIN" in role_names or (is_authenticated() and user.isSuperAdmin())'
));
// ...
}
}
In this example, if the current user has ROLE_ADMIN
or if the current
user object's isSuperAdmin()
method returns true
, then access will
be granted (note: your User object may not have an isSuperAdmin()
method,
that method is invented for this example).
The security expression must use any valid expression language syntax and can use any of these variables created by Symfony:
user
-
An instance of UserInterface
that represents the current user or
null
if you're not authenticated. role_names
-
An array with the string representation of the roles the user has. This array
includes any roles granted indirectly via the role hierarchy but it
does not include the
IS_AUTHENTICATED_*
attributes (see the functions below). object
-
The object (if any) that's passed as the second argument to
isGranted()
. subject
-
It stores the same value as
object
, so they are equivalent. token
- The token object.
trust_resolver
-
The AuthenticationTrustResolverInterface,
object: you'll probably use the
is_*()
functions below instead.
Additionally, you have access to a number of functions inside the expression:
is_authenticated()
-
Returns
true
if the user is authenticated via "remember-me" or authenticated "fully" - i.e. returns true if the user is "logged in". is_remember_me()
-
Similar, but not equal to
IS_AUTHENTICATED_REMEMBERED
, see below. is_fully_authenticated()
-
Equal to checking if the user has the
IS_AUTHENTICATED_FULLY
role. is_granted()
- Checks if the user has the given permission. Optionally accepts a second argument with the object where permission is checked on. It's equivalent to using the isGranted() method from the security service.
is_remember_me()
is different than checking IS_AUTHENTICATED_REMEMBERED
The is_remember_me()
and is_fully_authenticated()
functions are similar
to using IS_AUTHENTICATED_REMEMBERED
and IS_AUTHENTICATED_FULLY
with the isGranted()
function - but they are not the same. The
following controller snippet shows the difference:
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use Symfony\Component\ExpressionLanguage\Expression;
use Symfony\Component\Security\Core\Authorization\AuthorizationCheckerInterface;
// ...
public function index(AuthorizationCheckerInterface $authorizationChecker): Response
{
$access1 = $authorizationChecker->isGranted('IS_AUTHENTICATED_REMEMBERED');
$access2 = $authorizationChecker->isGranted(new Expression(
'is_remember_me() or is_fully_authenticated()'
));
}
Here, $access1
and $access2
will be the same value. Unlike the
behavior of IS_AUTHENTICATED_REMEMBERED
and IS_AUTHENTICATED_FULLY
,
the is_remember_me()
function only returns true if the user is authenticated
via a remember-me cookie and is_fully_authenticated()
only returns
true if the user has actually logged in during this session (i.e. is
full-fledged).
In case of the #[IsGranted]
attribute, the subject can also be an
Expression object:
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// src/Controller/MyController.php
namespace App\Controller;
use App\Entity\Post;
use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\ExpressionLanguage\Expression;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Security\Http\Attribute\IsGranted;
class MyController extends AbstractController
{
#[IsGranted(
attribute: new Expression('user === subject'),
subject: new Expression('args["post"].getAuthor()'),
)]
public function index(Post $post): Response
{
// ...
}
}
In this example, we fetch the author of the post and use it as the subject. If the subject matches the current user, then access will be granted.
The subject may also be an array where the key can be used as an alias for the result of an expression:
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#[IsGranted(
attribute: new Expression('user === subject["author"] and subject["post"].isPublished()'),
subject: [
'author' => new Expression('args["post"].getAuthor()'),
'post',
],
)]
public function index(Post $post): Response
{
// ...
}
Here, access will be granted if the author matches the current user
and the post's isPublished()
method returns true
.
You can also use the current request as the subject:
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#[IsGranted(
attribute: '...',
subject: new Expression('request'),
)]
public function index(): Response
{
// ...
}
Inside the subject's expression, you have access to two variables:
request
- The Symfony Request object that represents the current request.
args
- An array of controller arguments that are passed to the controller.