Expand description
If-None-Match
header, defined
in RFC 7232 §3.2
The If-None-Match
header field makes the request method conditional
on a recipient cache or origin server either not having any current
representation of the target resource, when the field-value is “*”,
or having a selected representation with an entity-tag that does not
match any of those listed in the field-value.
A recipient MUST use the weak comparison function when comparing entity-tags for If-None-Match (Section 2.3.2), since weak entity-tags can be used for cache validation even if there have been changes to the representation data.
ABNF
If-None-Match = "*" / 1#entity-tag
Example Values
"xyzzy"
W/"xyzzy"
"xyzzy", "r2d2xxxx", "c3piozzzz"
W/"xyzzy", W/"r2d2xxxx", W/"c3piozzzz"
*
Examples
use actix_web::HttpResponse;
use actix_web::http::header::IfNoneMatch;
let mut builder = HttpResponse::Ok();
builder.insert_header(IfNoneMatch::Any);
use actix_web::HttpResponse;
use actix_web::http::header::{IfNoneMatch, EntityTag};
let mut builder = HttpResponse::Ok();
builder.insert_header(
IfNoneMatch::Items(vec![
EntityTag::new(false, "xyzzy".to_owned()),
EntityTag::new(false, "foobar".to_owned()),
EntityTag::new(false, "bazquux".to_owned()),
])
);
Variants
Any
Any value is a match
Items(Vec<EntityTag>)
Only the listed items are a match
Trait Implementations
sourceimpl Clone for IfNoneMatch
impl Clone for IfNoneMatch
sourcefn clone(&self) -> IfNoneMatch
fn clone(&self) -> IfNoneMatch
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl Debug for IfNoneMatch
impl Debug for IfNoneMatch
sourceimpl Display for IfNoneMatch
impl Display for IfNoneMatch
sourceimpl Header for IfNoneMatch
impl Header for IfNoneMatch
sourcefn name() -> HeaderName
fn name() -> HeaderName
Returns the name of the header field.
sourcefn parse<M: HttpMessage>(msg: &M) -> Result<Self, ParseError>
fn parse<M: HttpMessage>(msg: &M) -> Result<Self, ParseError>
Parse the header from a HTTP message.
sourceimpl PartialEq<IfNoneMatch> for IfNoneMatch
impl PartialEq<IfNoneMatch> for IfNoneMatch
sourcefn eq(&self, other: &IfNoneMatch) -> bool
fn eq(&self, other: &IfNoneMatch) -> bool
This method tests for self
and other
values to be equal, and is used
by ==
. Read more
sourceimpl TryIntoHeaderValue for IfNoneMatch
impl TryIntoHeaderValue for IfNoneMatch
type Error = InvalidHeaderValue
type Error = InvalidHeaderValue
The type returned in the event of a conversion error.
sourcefn try_into_value(self) -> Result<HeaderValue, Self::Error>
fn try_into_value(self) -> Result<HeaderValue, Self::Error>
Try to convert value to a HeaderValue.
impl Eq for IfNoneMatch
impl StructuralEq for IfNoneMatch
impl StructuralPartialEq for IfNoneMatch
Auto Trait Implementations
impl RefUnwindSafe for IfNoneMatch
impl Send for IfNoneMatch
impl Sync for IfNoneMatch
impl Unpin for IfNoneMatch
impl UnwindSafe for IfNoneMatch
Blanket Implementations
sourceimpl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
const: unstable · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Qwhere
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
sourcefn equivalent(&self, key: &K) -> bool
fn equivalent(&self, key: &K) -> bool
Compare self to key
and return true
if they are equal.
sourceimpl<T> Instrument for T
impl<T> Instrument for T
sourcefn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
sourcefn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
sourceimpl<T> TryIntoHeaderPair for Twhere
T: Header,
impl<T> TryIntoHeaderPair for Twhere
T: Header,
type Error = <T as TryIntoHeaderValue>::Error
fn try_into_pair(
self
) -> Result<(HeaderName, HeaderValue), <T as TryIntoHeaderPair>::Error>
impl<V, T> VZip<V> for Twhere
V: MultiLane<T>,
impl<V, T> VZip<V> for Twhere
V: MultiLane<T>,
fn vzip(self) -> V
sourceimpl<T> WithSubscriber for T
impl<T> WithSubscriber for T
sourcefn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>where
S: Into<Dispatch>,
fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>where
S: Into<Dispatch>,
Attaches the provided Subscriber
to this type, returning a
WithDispatch
wrapper. Read more
sourcefn with_current_subscriber(self) -> WithDispatch<Self>
fn with_current_subscriber(self) -> WithDispatch<Self>
Attaches the current default Subscriber
to this type, returning a
WithDispatch
wrapper. Read more