Expand description
Rejections
Part of the power of the Filter
system is being able to
reject a request from a filter chain. This allows for filters to be
combined with or
, so that if one side of the chain finds that a request
doesn’t fulfill its requirements, the other side can try to process
the request.
Many of the built-in filters
will automatically reject
the request with an appropriate rejection. However, you can also build
new custom Filter
s and still want other routes to be
matchable in the case a predicate doesn’t hold.
As a request is processed by a Filter chain, the rejections are accumulated into
a list contained by the Rejection
type. Rejections from
filters can be handled using Filter::recover
.
This is a convenient way to map rejections into a Reply
.
For a more complete example see the Rejection Example from the repository.
§Example
use warp::{reply, Reply, Filter, reject, Rejection, http::StatusCode};
#[derive(Debug)]
struct InvalidParameter;
impl reject::Reject for InvalidParameter {}
// Custom rejection handler that maps rejections into responses.
async fn handle_rejection(err: Rejection) -> Result<impl Reply, std::convert::Infallible> {
if err.is_not_found() {
Ok(reply::with_status("NOT_FOUND", StatusCode::NOT_FOUND))
} else if let Some(e) = err.find::<InvalidParameter>() {
Ok(reply::with_status("BAD_REQUEST", StatusCode::BAD_REQUEST))
} else {
eprintln!("unhandled rejection: {:?}", err);
Ok(reply::with_status("INTERNAL_SERVER_ERROR", StatusCode::INTERNAL_SERVER_ERROR))
}
}
// Filter on `/:id`, but reject with InvalidParameter if the `id` is `0`.
// Recover from this rejection using a custom rejection handler.
let route = warp::path::param()
.and_then(|id: u32| async move {
if id == 0 {
Err(warp::reject::custom(InvalidParameter))
} else {
Ok("id is valid")
}
})
.recover(handle_rejection);
Modules§
- sealed 🔒
Macros§
Structs§
- Invalid request header
- Invalid query
- A content-length header is required
- HTTP method not allowed
- Missing cookie
- Missing request header
- The request payload is too large
- Rejection of a request by a
Filter
. - The request’s content-type is not supported
Enums§
Traits§
- Cause 🔒
- A marker trait to ensure proper types are used for custom rejections.
Functions§
- Protect against re-rejecting a rejection.
- Rejects a request with a custom cause.
- known 🔒
- Rejects a request with
404 Not Found
. - Rejects a request with
404 Not Found
.