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use std::fmt;
use {Header, Raw, Preference};
use parsing::{from_comma_delimited, fmt_comma_delimited};
///
/// The `Preference-Applied` response header may be included within a
/// response message as an indication as to which `Prefer` header tokens were
/// honored by the server and applied to the processing of a request.
///
/// # ABNF
///
/// ```text
/// Preference-Applied = "Preference-Applied" ":" 1#applied-pref
/// applied-pref = token [ BWS "=" BWS word ]
/// ```
///
/// # Example values
///
/// * `respond-async`
/// * `return=minimal`
/// * `wait=30`
///
/// # Examples
///
/// ```
/// use headers::{Headers, PreferenceApplied, Preference};
///
/// let mut headers = Headers::new();
/// headers.set(
/// PreferenceApplied(vec![Preference::RespondAsync])
/// );
/// ```
///
/// ```
/// use headers::{Headers, PreferenceApplied, Preference};
///
/// let mut headers = Headers::new();
/// headers.set(
/// PreferenceApplied(vec![
/// Preference::RespondAsync,
/// Preference::ReturnRepresentation,
/// Preference::Wait(10u32),
/// Preference::Extension("foo".to_owned(),
/// "bar".to_owned(),
/// vec![]),
/// ])
/// );
/// ```
#[derive(PartialEq, Clone, Debug)]
pub struct PreferenceApplied(pub Vec<Preference>);
__hyper__deref!(PreferenceApplied => Vec<Preference>);
impl Header for PreferenceApplied {
fn header_name() -> &'static str {
static NAME: &'static str = "Preference-Applied";
NAME
}
fn parse_header(raw: &Raw) -> ::Result<PreferenceApplied> {
let preferences = try!(from_comma_delimited(raw));
if !preferences.is_empty() {
Ok(PreferenceApplied(preferences))
} else {
Err(::Error::Header)
}
}
fn fmt_header(&self, f: &mut ::Formatter) -> fmt::Result {
f.fmt_line(self)
}
}
impl fmt::Display for PreferenceApplied {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
//TODO: format this without allocating a Vec and cloning contents
let preferences: Vec<_> = self.0.iter().map(|pref| match pref {
// The spec ignores parameters in `Preferences-Applied`
&Preference::Extension(ref name, ref value, _) => Preference::Extension(
name.to_owned(),
value.to_owned(),
vec![]
),
preference => preference.clone()
}).collect();
fmt_comma_delimited(f, &preferences)
}
}
#[cfg(test)]
mod tests {
use Preference;
use super::*;
#[test]
fn test_format_ignore_parameters() {
assert_eq!(
format!("{}", PreferenceApplied(vec![Preference::Extension(
"foo".to_owned(),
"bar".to_owned(),
vec![("bar".to_owned(), "foo".to_owned()), ("buz".to_owned(), "".to_owned())]
)])),
"foo=bar".to_owned()
);
}
}
bench_header!(normal,
PreferenceApplied, { vec![b"respond-async, return=representation".to_vec(), b"wait=100".to_vec()] });