.NET 7.0: Output Caching: Evaluate policy after other middleware processed the request

[Belphemur]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

When providing APIs to be used publicly, some error code like 404 might worth to be cache longer than success code since we know this state won't change anytime soon.

In my case, I provide an API to search for subtitle for shows.

The api take the searched show from the URL. It's more than possible that said show isn't available on my service yet.
I return a 404 and like to cache that result for longer than a succesful found show with subtitles.

Describe the solution you'd like

Delay evaluation of policy to when we have a response to let the developer use HttpContext.Response as part of rule for matching policy, like its status code.

Additional context

Currently we have access to the response using the .With(context => context.HttpContext.Response.StatusCode == 404); when defining a policy. The issue is, since the response isn't created yet, the status code is always 200.

Since there isn't yet a full documentation of the capabilities of the With method, it can leads to unexpected cases.

[ghost]

Thanks for contacting us.

We're moving this issue to the .NET 8 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[Belphemur]

I understand on that case, the doc should specify that the response can't be used to make output cache policies.