Update #[AsDbalType] attribute to register DBAL types as Symfony services

[GromNaN]

Update the #[AsDbalType] PHP attribute and a RegisterDbalTypePass compiler pass to register Doctrine DBAL types as Symfony services with a per-connection TypeRegistry, without touching the global static type registry.

The PR #2197 that added this attribute only supports injection of class names into the configuration. This PR requires DBAL and ORM changes to inject services.

How it works

• A new #[AsDbalType(name: 'money')] attribute tags the service with doctrine.dbal.type
• RegisterDbalTypePass builds a TypeRegistry per connection, populated with:
  • Config-based types (doctrine.dbal.types) as inline definitions
  • Service-tagged types as service references, resolved lazily through a ServiceLocator
• The TypeRegistry is wired to both the DBAL Configuration and the ORM Configuration of each associated entity manager
• Types can be restricted to specific connections by repeating the attribute: #[AsDbalType(name: 'money', connection: 'reporting')]

Because types are registered as services and resolved lazily, they support full dependency injection: a type class can declare constructor arguments and receive autowired or explicitly configured dependencies.

Example

use Doctrine\Bundle\DoctrineBundle\Attribute\AsDbalType;
use Doctrine\DBAL\Platforms\AbstractPlatform;
use Doctrine\DBAL\Types\Type;

#[AsDbalType(name: self::class /* by default */)]
final class MoneyType extends Type
{
    public function getSQLDeclaration(array $column, AbstractPlatform $platform): string
    {
        return $platform->getDecimalTypeDeclarationSQL($column);
    }
}

#[ORM\Column(type: MoneyType::class)]
private Money $price;

Backward compatibility (DBAL < 4.5)

Per-connection TypeRegistry injection requires DBAL >= 4.5. On older versions, the compiler pass falls back to registering the types in the global type registry through doctrine.dbal.connection_factory.types. This fallback has two limitations, both enforced at compile time:

• Dependency injection is not available: DBAL instantiates types with new $class(), so a type whose constructor has mandatory arguments is rejected with a clear error message.
• Per-connection restriction is not supported; types apply to all connections.

In this fallback, the type service definition is marked container.excluded since the type is instantiated by DBAL rather than consumed as a service.

Dependencies

This PR depends on changes in DBAL and ORM to support per-connection TypeRegistry:

• DBAL Add TypeRegistry to Configuration and use it in all internal type resolution dbal#7342
• ORM Replace static Type::* calls with instance-based TypeRegistry lookups orm#12421

Demo

A working example using #[AsDbalType] to store emails as base64 in the database is available at: GromNaN/symfony-demo#5

[GromNaN]

To be rebased after #2197

[derrabus]

@GromNaN Do you want to continue your work here?

[GromNaN]

I'll finish the PRs on DBAL and ORM before polishing this PR on the Bundle. In August.

[uuf6429]

Hi! I was a bit confused by the PR description seeing as the attribute already exists from the other PR linked above - could we maybe update it to explain why this PR is still needed or what's it trying to solve?

PS: I saw some documentation in that other PR which is quite good, but interestingly the only relevant reference in a Google search for "AsDbalType" brings me to this PR. Isn't that documentation published anywhere? AFAIK it's also missing on symfony. Aah, found it: https://www.doctrine-project.org/projects/doctrine-bundle/en/3.3/dbal-type.html

[GromNaN]

@uuf6429 Sorry for the confusion. This PR was created before the merge, but was not merged because it requires upstream work on DBAL and ORM. Thanks for pointing the inconsistence, I updated the title and description to reflect the current state.

[stof]

why supporting 2 different attribute names for the type name ?

[GromNaN]

Good point. I liked type better for the explicit tag configuration (shorter, reads nicely), but type_name is already the key shipped in 3.3.0, so keeping it avoids a BC break for anyone tagging a service by hand. I dropped the extra fallback and kept type_name as the only key.