Reuse the code of Extract when implementing Service.

[sunli829]

Feature Request

Motivation

I want to implement a Service for GraphQL query execution so as to avoid boilerplate code like the following.

https://github.com/async-graphql/examples/blob/7e3304e406adaff8d28a025becd91867ecae199a/axum/starwars/src/main.rs#L8

I have implemented a GraphQL request extractor, I want to implement Service can reuse it.

But I cannot use RequestParts::new because it is pub(crate), so should we change to pub?
Or there is a better solution, please tell me. 🙂

[davidpdrsn]

I think we could look into making RequestParts usable outside axum.

Would have to think a bit more about the design however. new is pretty straight forward but I imagine users would want into_request as well. That is currently not very idiomatic since it takes &mut self (into_* methods normally take self) and panics if the request body has been extracted (to avoid requiring B: Default which might be problematic).

Or maybe there is a totally different way of making extractors usable from services that don't require these bits being public 🤔

If you wanna ship something in async-graphql, and don't want to wait for this, I would probably recommend writing a service without using an extractor for axum.

[davidpdrsn]

I was able to clean up the API of RequestParts in #167. I think we could consider exposing the API as it is now.

[sunli829]

So we only need to change pub(crate) to pub now? 🙂

[davidpdrsn]

Pretty much 😅 I still wanna do some experimentation and see what its actually like to use.

[davidpdrsn]

I've been thinking about this and actually think its fine to make the methods pub. Just requires writing some docs.