Description

Since version 6.1 it is possible to exclude a service from a TaggedIterator (Living on the edge blog post).

Unfortunately, it is not possible to add an alias with a PHP attribute. This is the only missing feature needed to avoid writing configuration in YAML.

I asked about this feature on Slack and @wouterj told me that attributes for DI config is not aimed to be used for creating services.
However in this another blog post, @nicolas-grekas said that PR are welcome for this feature. So that's why I opened this issue.

Example

My use case is the following:

classDiagram
HandlerInterface <|-- HandlerA : implements
HandlerInterface <|-- HandlerB : implements
HandlerInterface <|-- CompositeHandler : implements
CompositeHandler : -iterable~HandlerInterface~ handlers
class HandlerInterface {
    <<interface>>
    +handle() void
}
class HandlerA {
    +handle() void
}
class HandlerB {
    +handle() void
}
class CompositeHandler {
    +handle() void
}

#[AutoconfigureTag(name: 'app.handler')]
interface HandlerInterface {
    public function handle(): void;
}

class CompositeHandler implements HandlerInterface {

    public function __construct(
        #[TaggedIterator(tag: 'app.handler', exclude: self::class)],
        private iterable $handlers
    ) {
    }

    public function handle(): void {
        foreach ($this->handlers as $handler) {
            $handler->handle();
        }
    }
}

As I need to inject HandlerInterface into another service, I will write the following YAML configuration to create an alias between the HandlerInterface and CompositeHandler:

services:
    app.handler:
        class: CompositeHandler
        
    HandlerInterface: '@app.handler'

From my point of view, define the alias with an attribute would simplify the configuration for this kind of cases.