pub struct ReqData<T: Clone + 'static>(/* private fields */);
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.
§Examples
#[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 option extractor if middleware is not guaranteed to add this type of req data
if let Some(flag) = opt_flag {
assert_eq!(&flag.into_inner(), req.extensions().get::<FlagFromMiddleware>().unwrap());
}
HttpResponse::Ok()
}
Implementations§
Trait Implementations§
source§impl<T: Clone + 'static> FromRequest for ReqData<T>
impl<T: Clone + 'static> FromRequest for ReqData<T>
source§fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future
fn from_request(req: &HttpRequest, _: &mut Payload) -> Self::Future
Self
from request parts asynchronously.Auto Trait Implementations§
impl<T> Freeze for ReqData<T>where
T: Freeze,
impl<T> RefUnwindSafe for ReqData<T>where
T: RefUnwindSafe,
impl<T> Send for ReqData<T>where
T: Send,
impl<T> Sync for ReqData<T>where
T: Sync,
impl<T> Unpin for ReqData<T>where
T: Unpin,
impl<T> UnwindSafe for ReqData<T>where
T: UnwindSafe,
Blanket Implementations§
source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
source§default unsafe fn clone_to_uninit(&self, dst: *mut T)
default unsafe fn clone_to_uninit(&self, dst: *mut T)
clone_to_uninit
)