[DependencyInjection] Add support for excluding services with declared custom attribute

[angelov]

Q	A
Branch?	6.4
Bug fix?	no
New feature?	yes
Deprecations?	no
Tickets	/
License	MIT
Doc PR	TODO

Currently, if we want to exclude classes from registering as services in the container, we can add their namespace(s) in the app configuration, or use the #[Exclude]/#[When('never')] attributes on each of the classes.

When it comes to certain types of classes, eg. entities, they can be placed all around the apps in many different folders, which can result in many entries under the exclude configuration. It is also usual for us to have many entity classes, so adding the attribute to each of them can be error-prone.

However, classes of a same type may already have a common attribute declared on them - such as Doctrine\ORM\Mapping\Entity.

Because of that, I'm proposing a new way for excluding classes by making it possible to register any attribute for exclusion.

Underneath, this is just extending the functionality for handling the classes with #[Exclude] attribute by additionally checking the list of attributes marked for exclusion.

Usage:

To exclude all classes with the #[Entity] attribute:

use Doctrine\ORM\Mapping\Entity;
use Symfony\Bundle\FrameworkBundle\Kernel\MicroKernelTrait;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpKernel\Kernel as BaseKernel;

class Kernel extends BaseKernel
{
    use MicroKernelTrait;

    protected function build(ContainerBuilder $container)
    {
        $container->registerAttributeForExclusion(Entity::class);
    }
}

[angelov]

The failures in the checks seem unrelated.

[nicolas-grekas]

It'd be great to allow this feature to work even if the attribute class doesn't not exist.
Can you remove this one and make the feature still work?

[nicolas-grekas]

IIRC, file loaders are run on separate container instances, right? This would mean that a bundle cannot expect registerAttributeForExclusion to have any effect on classes in src/. Am I correct? If yes, don't we want to make these app-wide instead?

[nicolas-grekas]

what about this? did you give it a try? configuring an exclusion within a bundle and seeing it work on the app?

[nicolas-grekas]

Small rebase needed, but more importantly: did you try using registerForAutoconfiguration to define the container.exclude tag?

[nicolas-grekas]

Suggested change

	* Add support for excluding services with declared custom attribute (`ContainerBuilder::registerAttributeForExclusion`)
	* Add support for excluding services by attribute with `ContainerBuilder::registerAttributeForExclusion()`

[nicolas-grekas]

?

Suggested change

	* @var array<class-string>
	* @var array<class-string, true>

[nicolas-grekas]

what about this? did you give it a try? configuring an exclusion within a bundle and seeing it work on the app?