Get context in interface field resolvers

[stijnfrishert]

One of my interface's fields resolves to another type. I'd like to store that field as an ID and retrieve it from my context upon resolution. Whenever I try this, I get an error saying the trait bound FromInputValue is not satisfied for my context.

struct Event {
    parent: Option<ID>,
}

juniper::graphql_interface!(Event: Context |&self| {
    field parent(context: &Context) -> Option<Event> { ... }

    // ...
}

This leads me to believe this is simply not supported in the current 0.14.2 release. Is this something I should also wait for in the new interface release that's coming up, or am I missing something?

[LegNeato]

Hmm, I think something similar should work but haven't looked at release version in a long time. After #682 lands this should be fixed on master.

[davidpdrsn]

I don't exactly remember but I don't think you should specify the context argument on the field itself:

juniper::graphql_interface!(Event: Context |&self| {
    field parent() -> Option<Event> { ... }

    // ...
}

That is at least what I do in juniper-from-schema here and here.

[stijnfrishert]

Oh nice, thanks, @davidpdrsn! I'll give that a try :)

---

@davidpdrsn: Sorry, it was late yesterday, but am I missing something or isn't that the exact same code as in the original post?

In any case, with that code trying to use a context inside the field body I get cannot find value *context* in scope.

[tyranron]

This is now possible in master. See description in Book.