Support resolving keyed services from DI in RDF and RDG

[captainsafia]

Description

This PR adds support for generating the appropriate code gen, for both run-time and compile-time generation strategies, to resolve keyed services from dependency injection in minimal APIs.

Fixes #49633

Customer Impact

Support for keyed services was added to the runtime in .NET 8 Preview 7. This change allows customers to leverage keyed services in their minimal APIs and contributes to a more complete user experience.

Regression?

• Yes
• No

Risk

• High
• Medium
• Low

Low risk, because the change is additive and doesn't affect pre-existing codepaths around parameter binding

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A

[ghost]

Hi @captainsafia. Please make sure you've updated the PR description to use the Shiproom Template. Also, make sure this PR is not marked as a draft and is ready-to-merge.

To learn more about how to prepare a servicing PR click here.

[captainsafia]

Approved via email.

[ghost]

Hi @captainsafia. This PR was just approved to be included in the upcoming servicing release. Somebody from the @dotnet/aspnet-build team will get it merged when the branches are open. Until then, please make sure all the CI checks pass and the PR is reviewed.

[halter73]

Should we ask for [FromKeyedServices] to add a AttributeTargets.Property target for [AsParameters] support? Should we define our own attribute for this purpose since [FromServices] does support properties and it's an unfortunate gap?

[captainsafia]

@halter73 Good question! I'd be curious to hear @benjaminpetit thoughts on the scenario as well.

IMO, the bigger issue with the lack of AttributeUsage.Property is the fact that this wouldn't play nice with MVC's implicit surrogate model for arguments.

@benjaminpetit Is adding another AttributeUsage considered an API change here that we could do for .NET 8?

FWIW, I don't believe we'll need to do any reaction to it in ASP.NET once it's enabled since we already support recursing into the type so it's relatively cheap.

[benjaminpetit]

@benjaminpetit Is adding another AttributeUsage considered an API change here that we could do for .NET 8?

No idea. I am not sure it's the way to go, since it would be specific for this use case (unless I am missing something).

Maybe defining your own attribute might be better, even if it might be confusing with all these attributes...

[captainsafia]

@benjaminpetit Spoke with Ben offline.

Personally, I'd prefer that we add the AttributeUsage.Property in the attribute in the runtime over creating a new attribute in ASP.NET Core. I want to avoid reproducing the problems we currently have with multiple variants of similar attributes throughout the stack.

For .NET 8, I'm more comfortable with an attribute that is consistent throughout all implementations but limited in functionality than inconsistent attributes with different behaviors.

[JamesNK]

FromKeyedService should support properties.

That would also allow DI containers that support property setters to use it.

[ghost]

@captainsafia, this change will be considered for inclusion in the blog post for the release it'll ship in. Nice work!

Please ensure that the original comment in this thread contains a clear explanation of what the change does, why it's important (what problem does it solve?), and, if relevant, include things like code samples and/or performance numbers.

This content may not be exactly what goes into the blog post, but it will help the team putting together the announcement.

Thanks!