[12.x] Adds a new "Alias" contextual attribute

[hijhem]

Motivation

Laravel provides a way to define an alias when registering a service in the container, which is convenient when initializing a subset of the service and using it in different parts of the application.

// Service
class State
{
    public function __construct(private string $storageKey) {}
}

// AppServiceProvider
$this->app->bind('module1.state', fn () => new State('module1'));
$this->app->bind('module2.state', fn () => new State('module2'));

However, there is no straightforward way to inject these instances into multiple services without manually binding them in the service provider.

Solution

A new Alias contextual attribute allows dependencies to be resolved by their alias.

class Service
{
    public function __construct(private #[Alias('module1.state')] State $state) {}
}

This ensures that the correct instance of State is resolved based on the specified alias.

[henzeb]

maybe we can do something with abstract? just like the method parameter is named? I don' t know, Alias feels confusing as it is also used for aliassing classes like the facades.

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!