Struct actix_web::web::ReqData [−][src]
pub struct ReqData<T: Clone + 'static>(_);
Expand description
Request-local data extractor.
Request-local data is arbitrary data attached to an individual request, usually
by middleware. It can be set via extensions_mut
on HttpRequest
or ServiceRequest
.
Unlike app data, request data is dropped when the request has finished processing. This makes it useful as a kind of messaging system between middleware and request handlers. It uses the same types-as-keys storage system as app data.
Mutating Request Data
Note that since extractors must output owned data, only types that impl Clone
can use this
extractor. A clone is taken of the required request data and can, therefore, not be directly
mutated in-place. To mutate request data, continue to use HttpRequest::extensions_mut
or
re-insert the cloned data back into the extensions map. A DerefMut
impl is intentionally not
provided to make this potential foot-gun more obvious.
Example
#[derive(Debug, Clone, PartialEq)]
struct FlagFromMiddleware(String);
/// Use the `ReqData<T>` extractor to access request data in a handler.
async fn handler(
req: HttpRequest,
opt_flag: Option<web::ReqData<FlagFromMiddleware>>,
) -> impl Responder {
// use an optional extractor if the middleware is
// not guaranteed to add this type of requests data
if let Some(flag) = opt_flag {
assert_eq!(&flag.into_inner(), req.extensions().get::<FlagFromMiddleware>().unwrap());
}
HttpResponse::Ok()
}
Implementations
Consumes the ReqData
, returning its wrapped data.
Trait Implementations
Auto Trait Implementations
impl<T> RefUnwindSafe for ReqData<T> where
T: RefUnwindSafe,
impl<T> UnwindSafe for ReqData<T> where
T: UnwindSafe,
Blanket Implementations
Mutably borrows from an owned value. Read more
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
Instruments this type with the provided Span
, returning an
Instrumented
wrapper. Read more
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