conditional compilation routes and data.

[alkeryn]

Hey! is there a way that isn't too cumbersome to have some routes present only if compiled with a specific feature flag or stuff like that ?
we can't put a #[cfg] macro between two .route() so i wonder if there is a clean way to do it.
i thought of doing something like

.configure(if cfg!(feature = "tests") { testroutes::get_routes } else { noop })

but that doesn't seem clean ^^
also i haven't found a good solution for app_data().

maybe it is possible to define App outside http server ?
or should we use a big configure function that has the conditions here ?

thank you ! :)

[robjtede]

use actix_web::{web, App, HttpRequest, HttpServer, Responder};

async fn greet(req: HttpRequest) -> impl Responder {
    let name = req.match_info().get("name").unwrap_or("World");
    format!("Hello {}!", &name)
}

#[actix_web::main]
async fn main() -> std::io::Result<()> {
    HttpServer::new(|| {
        let app = App::new().route("/", web::get().to(greet));

        let app = if cfg!(feature = "on") {
            app.configure(|cfg| {
                cfg.route("/on", web::get().to(greet));
            })
        } else {
            app
        };

        let app = app.route("/{name}", web::get().to(greet));

        app
    })
    .bind(("127.0.0.1", 8080))?
    .run()
    .await
}

[robjtede]

I've updated my original answer with something more correct and complete that compiles.

[robjtede]

Also, no you cannot create App outside the HttpServer closure since it is not Clone or Send.

[alkeryn]

hey thanks ! :)

[Cakeday]

just FYI, the cfg! macro doesn't conditionally compile: https://doc.rust-lang.org/std/macro.cfg.html.

[alkeryn]

@Cakeday whilst true, in the given example it unfolds to an if(true), but then the compiler optimisations will just remove the if part most likely because it is known at compile time that it will always be true so i feel like it still kind of is.
thanks though :)