1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61
use HeaderValue;
/// The `Pragma` header defined by HTTP/1.0.
///
/// > The "Pragma" header field allows backwards compatibility with
/// > HTTP/1.0 caches, so that clients can specify a "no-cache" request
/// > that they will understand (as Cache-Control was not defined until
/// > HTTP/1.1). When the Cache-Control header field is also present and
/// > understood in a request, Pragma is ignored.
/// > In HTTP/1.0, Pragma was defined as an extensible field for
/// > implementation-specified directives for recipients. This
/// > specification deprecates such extensions to improve interoperability.
///
/// Spec: [https://tools.ietf.org/html/rfc7234#section-5.4][url]
///
/// [url]: https://tools.ietf.org/html/rfc7234#section-5.4
///
/// # Examples
///
/// ```
/// # extern crate headers;
/// use headers::Pragma;
///
/// let pragma = Pragma::no_cache();
/// ```
#[derive(Clone, Debug, PartialEq)]
pub struct Pragma(HeaderValue);
derive_header! {
Pragma(_),
name: PRAGMA
}
impl Pragma {
/// Construct the literal `no-cache` Pragma header.
pub fn no_cache() -> Pragma {
Pragma(HeaderValue::from_static("no-cache"))
}
/// Return whether this pragma is `no-cache`.
pub fn is_no_cache(&self) -> bool {
self.0 == "no-cache"
}
}
#[cfg(test)]
mod tests {
use super::super::test_decode;
use super::Pragma;
#[test]
fn no_cache_is_no_cache() {
assert!(Pragma::no_cache().is_no_cache());
}
#[test]
fn etc_is_not_no_cache() {
let ext = test_decode::<Pragma>(&["dexter"]).unwrap();
assert!(!ext.is_no_cache());
}
}