Struct axum::routing::method_routing::MethodRouter

source · [−]
pub struct MethodRouter<S = (), B = Body, E = Infallible> { /* private fields */ }
Expand description

A Service that accepts requests based on a MethodFilter and allows chaining additional handlers and services.

When does MethodRouter implement Service?

Whether or not MethodRouter implements Service depends on the state type it requires.

use tower::Service;
use axum::{routing::get, extract::State, body::Body, http::Request};

// this `MethodRouter` doesn't require any state, i.e. the state is `()`,
let method_router = get(|| async {});
// and thus it implements `Service`
assert_service(method_router);

// this requires a `String` and doesn't implement `Service`
let method_router = get(|_: State<String>| async {});
// until you provide the `String` with `.with_state(...)`
let method_router_with_state = method_router.with_state(String::new());
// and then it implements `Service`
assert_service(method_router_with_state);

// helper to check that a value implements `Service`
fn assert_service<S>(service: S)
where
    S: Service<Request<Body>>,
{}

Implementations

Chain an additional handler that will accept requests matching the given MethodFilter.

Example
use axum::{
    routing::get,
    Router,
    routing::MethodFilter
};

async fn handler() {}

async fn other_handler() {}

// Requests to `GET /` will go to `handler` and `DELETE /` will go to
// `other_handler`
let app = Router::new().route("/", get(handler).on(MethodFilter::DELETE, other_handler));

Chain an additional handler that will only accept DELETE requests.

See MethodRouter::get for an example.

Chain an additional handler that will only accept GET requests.

Example
use axum::{routing::post, Router};

async fn handler() {}

async fn other_handler() {}

// Requests to `POST /` will go to `handler` and `GET /` will go to
// `other_handler`.
let app = Router::new().route("/", post(handler).get(other_handler));

Note that get routes will also be called for HEAD requests but will have the response body removed. Make sure to add explicit HEAD routes afterwards.

Chain an additional handler that will only accept HEAD requests.

See MethodRouter::get for an example.

Chain an additional handler that will only accept OPTIONS requests.

See MethodRouter::get for an example.

Chain an additional handler that will only accept PATCH requests.

See MethodRouter::get for an example.

Chain an additional handler that will only accept POST requests.

See MethodRouter::get for an example.

Chain an additional handler that will only accept PUT requests.

See MethodRouter::get for an example.

Chain an additional handler that will only accept TRACE requests.

See MethodRouter::get for an example.

Add a fallback Handler to the router.

Convert the handler into a MakeService.

This allows you to serve a single handler if you don’t need any routing:

use axum::{
    Server,
    handler::Handler,
    http::{Uri, Method},
    response::IntoResponse,
    routing::get,
};
use std::net::SocketAddr;

async fn handler(method: Method, uri: Uri, body: String) -> String {
    format!("received `{} {}` with body `{:?}`", method, uri, body)
}

let router = get(handler).post(handler);

Server::bind(&SocketAddr::from(([127, 0, 0, 1], 3000)))
    .serve(router.into_make_service())
    .await?;

Create a default MethodRouter that will respond with 405 Method Not Allowed to all requests.

Provide the state for the router.

Chain an additional service that will accept requests matching the given MethodFilter.

Example
use axum::{
    http::Request,
    Router,
    routing::{MethodFilter, on_service},
};
use http::Response;
use std::convert::Infallible;
use hyper::Body;

let service = tower::service_fn(|request: Request<Body>| async {
    Ok::<_, Infallible>(Response::new(Body::empty()))
});

// Requests to `DELETE /` will go to `service`
let app = Router::new().route("/", on_service(MethodFilter::DELETE, service));

Chain an additional service that will only accept DELETE requests.

See MethodRouter::get_service for an example.

Chain an additional service that will only accept GET requests.

Example
use axum::{
    http::Request,
    Router,
    routing::post_service,
};
use http::Response;
use std::convert::Infallible;
use hyper::Body;

let service = tower::service_fn(|request: Request<Body>| async {
    Ok::<_, Infallible>(Response::new(Body::empty()))
});

let other_service = tower::service_fn(|request: Request<Body>| async {
    Ok::<_, Infallible>(Response::new(Body::empty()))
});

// Requests to `POST /` will go to `service` and `GET /` will go to
// `other_service`.
let app = Router::new().route("/", post_service(service).get_service(other_service));

Note that get routes will also be called for HEAD requests but will have the response body removed. Make sure to add explicit HEAD routes afterwards.

Chain an additional service that will only accept HEAD requests.

See MethodRouter::get_service for an example.

Chain an additional service that will only accept OPTIONS requests.

See MethodRouter::get_service for an example.

Chain an additional service that will only accept PATCH requests.

See MethodRouter::get_service for an example.

Chain an additional service that will only accept POST requests.

See MethodRouter::get_service for an example.

Chain an additional service that will only accept PUT requests.

See MethodRouter::get_service for an example.

Chain an additional service that will only accept TRACE requests.

See MethodRouter::get_service for an example.

Add a fallback service to the router.

This service will be called if no routes matches the incoming request.

use axum::{
    Router,
    routing::get,
    handler::Handler,
    response::IntoResponse,
    http::{StatusCode, Method, Uri},
};

let handler = get(|| async {}).fallback(fallback);

let app = Router::new().route("/", handler);

async fn fallback(method: Method, uri: Uri) -> (StatusCode, String) {
    (StatusCode::NOT_FOUND, format!("`{}` not allowed for {}", method, uri))
}
When used with MethodRouter::merge

Two routers that both have a fallback cannot be merged. Doing so results in a panic:

ⓘ
use axum::{
    routing::{get, post},
    handler::Handler,
    response::IntoResponse,
    http::{StatusCode, Uri},
};

let one = get(|| async {}).fallback(fallback_one);

let two = post(|| async {}).fallback(fallback_two);

let method_route = one.merge(two);

async fn fallback_one() -> impl IntoResponse { /* ... */ }
async fn fallback_two() -> impl IntoResponse { /* ... */ }
Setting the Allow header

By default MethodRouter will set the Allow header when returning 405 Method Not Allowed. This is also done when the fallback is used unless the response generated by the fallback already sets the Allow header.

This means if you use fallback to accept additional methods, you should make sure you set the Allow header correctly.

Apply a tower::Layer to all routes in the router.

This can be used to add additional processing to a request for a group of routes.

Note that the middleware is only applied to existing routes. So you have to first add your routes (and / or fallback) and then call layer afterwards. Additional routes added after layer is called will not have the middleware added.

Works similarly to Router::layer. See that method for more details.

Example
use axum::{routing::get, Router};
use tower::limit::ConcurrencyLimitLayer;

async fn hander() {}

let app = Router::new().route(
    "/",
    // All requests to `GET /` will be sent through `ConcurrencyLimitLayer`
    get(hander).layer(ConcurrencyLimitLayer::new(64)),
);

Apply a tower::Layer to the router that will only run if the request matches a route.

Note that the middleware is only applied to existing routes. So you have to first add your routes (and / or fallback) and then call layer afterwards. Additional routes added after layer is called will not have the middleware added.

This works similarly to MethodRouter::layer except the middleware will only run if the request matches a route. This is useful for middleware that return early (such as authorization) which might otherwise convert a 405 Method Not Allowed into a 401 Unauthorized.

Example
use axum::{
    routing::get,
    Router,
};
use tower_http::validate_request::ValidateRequestHeaderLayer;

let app = Router::new().route(
    "/foo",
    get(|| async {})
        .route_layer(ValidateRequestHeaderLayer::bearer("password"))
);

// `GET /foo` with a valid token will receive `200 OK`
// `GET /foo` with a invalid token will receive `401 Unauthorized`
// `POST /FOO` with a invalid token will receive `405 Method Not Allowed`

Merge two routers into one.

This is useful for breaking routers into smaller pieces and combining them into one.

use axum::{
    routing::{get, post},
    Router,
};

let get = get(|| async {});
let post = post(|| async {});

let merged = get.merge(post);

let app = Router::new().route("/", merged);

// Our app now accepts
// - GET /
// - POST /

Apply a HandleErrorLayer.

This is a convenience method for doing self.layer(HandleErrorLayer::new(f)).

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Returns the “default value” for a type. Read more
The type of future calling this handler returns.
Call the handler with the given request.
Apply a tower::Layer to the handler. Read more
Convert the handler into a Service by providing the state
Responses given by the service.
Errors produced by the service.
The future response value.
Returns Poll::Ready(Ok(())) when the service is able to process requests. Read more
Process the request and return the response asynchronously. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Converts to this type from a reference to the input type.
Convert the handler into a Service and no state.
Convert the handler into a MakeService and no state. Read more
Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Yields a mutable reference to the service when it is ready to accept a request.
👎Deprecated since 0.4.6: please use the ServiceExt::ready method instead
Yields a mutable reference to the service when it is ready to accept a request.
Yields the service when it is ready to accept a request.
Consume this Service, calling with the providing request once it is ready.
Process all requests from the given Stream, and produce a Stream of their responses. Read more
Executes a new future after this service’s future resolves. This does not alter the behaviour of the poll_ready method. Read more
Maps this service’s response value to a different value. This does not alter the behaviour of the poll_ready method. Read more
Maps this service’s error value to a different value. This does not alter the behaviour of the poll_ready method. Read more
Maps this service’s result type (Result<Self::Response, Self::Error>) to a different value, regardless of whether the future succeeds or fails. Read more
Composes a function in front of the service. Read more
Composes an asynchronous function after this service. Read more
Composes a function that transforms futures produced by the service. Read more
Convert the service into a Service + Send trait object. Read more
Convert the service into a Service + Clone + Send trait object. Read more
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more