Consider making web::Path and web::Query fields public again

[luisholanda]

Hello! First of all thanks for the awesome work being done in the libraries!

While updating our company's codebase to tokio v1 (and thus actix-web v4) we noticed that #1894 made the field of web::Path and web::Query private. This change alone broke almost all our services' routes.

Given that the web::Json and web::Form still have their field public, it would be possible to rollback the change made in the former types? Having the fields private is a big burden for us, having to call .into_inner() everywhere is pretty annoying.

I can send a PR if this change is desired by the maintainers.

Your Environment

• Rust Version (I.e, output of rustc -V): nightly-2021-01-25
• Actix Web Version: 4.0.0-beta.3

[robjtede]

It has been considered a mistake to make the Path inner field public in v3 for reasons that do not affect Json or Form or Query.

Given Path is primarily used with tuples, a public inner field was making it quite confusing for developers that there was a difference between path.0 -> (String, String) and path.1 -> String. The possible solutions to this discontinuity are to either remove the public field or remove the Deref impl. The former was chosen as to affect fewer use cases.

It's like the Query public inner field was removed by mistake, or else I do not recall the rationale for it.

[luisholanda]

The rationale makes sense. Unfortunately, in our codebase, we destruct web::* types as soon as we receive them, so the change hit us really hard.

If most users make use of the Deref impl, I also think is better to keep it and we will rollback to using .into_inner().

It's like the Query public inner field was removed by mistake, or else I do not recall the rationale for it.

If so, it is possible to make at least it's field public?

[dxps]

Hi everyone,

I am using actix-web = "4.0.0-beta.8" and if this aspect has been solved,
then can you tell me please why such approach does not work anymore (as it is working in v3) ❔
Thanks.

In v3:

pub async fn some_handler(
    web::Path(tutor_id, course_id): web::Path<(i32, i32)>,
) -> ... {

In v4: we have to just mention some params and destructure it:

pub async fn some_handler(
    params: web::Path<(i32, i32)>,
) -> ... {
    let (tutor_id, course_id) = params.into_inner();

Update:
Ok, it seems that what @robjtede mentioned is still the decision for this change.
I'd say at least to have such (quite impactful, right?) change explicit in the Migration to v4, at least.

[robjtede]

I'd say at least to have such change explicit in the Migration to v4, at least.

Yep we're going to fill in the migration guide before stable release.

[ModProg]

To be able to update one of my projects with little hassle, I created this https://github.com/ModProg/actix-web-public-path .

Still think it is very nice to be able to declare your request like functions and get your path arguments directly in the declaration without need for an additional into_inner but I understand the reasoning behind the decision.

[robjtede]

Should have mentioned it here but there's a variant with public field in actix-web-lab, too.

https://docs.rs/actix-web-lab/0.15.0/actix_web_lab/extract/struct.Path.html