Description

This PR introduces a new #[AsVoter] attribute that allows security voters to declare their priority directly within the class, as proposed in issue #43074.

Motivation

While #[AsTaggedItem] or #[Autoconfigure] can technically set voter priority, they require manually specifying tag names and options, making the configuration verbose, error-prone, and less intuitive.

The goal of #[AsVoter] is to simplify voter configuration and make it explicit, intuitive, and easy to use, following the pattern of other Symfony attributes such as #[AsEventListener].

The #[AsVoter] attribute provides:

• Clearer intent: Explicitly designed for security voters
• Better developer experience: More discoverable and easier to understand than generic tag configuration
• Consistency: Aligns with other component-specific attributes like #[AsCommand], #[AsEventListener], #[AsMessageHandler], etc.
• Foundation for future enhancements: Provides a dedicated attribute that can be extended with additional voter-specific configuration options in the future

Behavior

• The attribute can be added once per class
• The #[AsVoter] attribute overrides YAML configuration and other attributes ( #[AsTaggedItem] #[Autoconfigure])
• This ensures the in-class configuration is always respected

Before

// config/services.yaml
services:
    App\Security\Voter\PostVoter:
        tags:
            - { name: security.voter, priority: 100 }

use Symfony\Component\DependencyInjection\Attribute\AsTaggedItem;

#[AsTaggedItem('security.voter', ['priority' => 100])]
class PostVoter implements VoterInterface
{
    public function vote(TokenInterface $token, mixed $subject, array $attributes): int
    {
        // ...
    }
}

After

use Symfony\Component\Security\Core\Attribute\AsVoter;

#[AsVoter(priority: 100)]
class PostVoter implements VoterInterface
{
    public function vote(TokenInterface $token, mixed $subject, array $attributes): int
    {
        // ...
    }
}