axum/examples/versioning.rs
David Pedersen f32d325e55
Make extractors easier to write (#36)
Previously extractors worked directly on `Request<B>` which meant you
had to do weird tricks like `mem::take(req.headers_mut())` to get owned
parts of the request.

This changes that instead to use a new `RequestParts` type that have
methods to "take" each part of the request. Without having to do weird
tricks.

Also removed the need to have `B: Default` for body extractors.
2021-07-22 13:23:50 +02:00

59 lines
1.4 KiB
Rust

use axum::response::IntoResponse;
use axum::{
async_trait,
extract::{FromRequest, RequestParts},
prelude::*,
};
use http::Response;
use http::StatusCode;
use std::net::SocketAddr;
#[tokio::main]
async fn main() {
// build our application with some routes
let app = route("/:version/foo", get(handler));
// run it
let addr = SocketAddr::from(([127, 0, 0, 1], 3000));
tracing::debug!("listening on {}", addr);
hyper::Server::bind(&addr)
.serve(app.into_make_service())
.await
.unwrap();
}
async fn handler(version: Version) {
println!("received request with version {:?}", version);
}
#[derive(Debug)]
enum Version {
V1,
V2,
V3,
}
#[async_trait]
impl<B> FromRequest<B> for Version
where
B: Send,
{
type Rejection = Response<Body>;
async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
let params = extract::UrlParamsMap::from_request(req)
.await
.map_err(IntoResponse::into_response)?;
let version = params
.get("version")
.ok_or_else(|| (StatusCode::NOT_FOUND, "version param missing").into_response())?;
match version {
"v1" => Ok(Version::V1),
"v2" => Ok(Version::V2),
"v3" => Ok(Version::V3),
_ => Err((StatusCode::NOT_FOUND, "unknown version").into_response()),
}
}
}