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use std::fmt;
use http::{HeaderName, HeaderValue};
use mime::Mime;
use crate::{Error, Header};
/// `Content-Type` header, defined in
/// [RFC7231](https://datatracker.ietf.org/doc/html/rfc7231#section-3.1.1.5)
///
/// The `Content-Type` header field indicates the media type of the
/// associated representation: either the representation enclosed in the
/// message payload or the selected representation, as determined by the
/// message semantics. The indicated media type defines both the data
/// format and how that data is intended to be processed by a recipient,
/// within the scope of the received message semantics, after any content
/// codings indicated by Content-Encoding are decoded.
///
/// Although the `mime` crate allows the mime options to be any slice, this crate
/// forces the use of Vec. This is to make sure the same header can't have more than 1 type. If
/// this is an issue, it's possible to implement `Header` on a custom struct.
///
/// # ABNF
///
/// ```text
/// Content-Type = media-type
/// ```
///
/// # Example values
///
/// * `text/html; charset=utf-8`
/// * `application/json`
///
/// # Examples
///
/// ```
/// use headers::ContentType;
///
/// let ct = ContentType::json();
/// ```
#[derive(Clone, Debug, PartialEq)]
pub struct ContentType(Mime);
impl ContentType {
/// A constructor to easily create a `Content-Type: application/json` header.
#[inline]
pub fn json() -> ContentType {
ContentType(mime::APPLICATION_JSON)
}
/// A constructor to easily create a `Content-Type: text/plain` header.
#[inline]
pub fn text() -> ContentType {
ContentType(mime::TEXT_PLAIN)
}
/// A constructor to easily create a `Content-Type: text/plain; charset=utf-8` header.
#[inline]
pub fn text_utf8() -> ContentType {
ContentType(mime::TEXT_PLAIN_UTF_8)
}
/// A constructor to easily create a `Content-Type: text/html` header.
#[inline]
pub fn html() -> ContentType {
ContentType(mime::TEXT_HTML)
}
/// A constructor to easily create a `Content-Type: text/xml` header.
#[inline]
pub fn xml() -> ContentType {
ContentType(mime::TEXT_XML)
}
/// A constructor to easily create a `Content-Type: application/www-form-url-encoded` header.
#[inline]
pub fn form_url_encoded() -> ContentType {
ContentType(mime::APPLICATION_WWW_FORM_URLENCODED)
}
/// A constructor to easily create a `Content-Type: image/jpeg` header.
#[inline]
pub fn jpeg() -> ContentType {
ContentType(mime::IMAGE_JPEG)
}
/// A constructor to easily create a `Content-Type: image/png` header.
#[inline]
pub fn png() -> ContentType {
ContentType(mime::IMAGE_PNG)
}
/// A constructor to easily create a `Content-Type: application/octet-stream` header.
#[inline]
pub fn octet_stream() -> ContentType {
ContentType(mime::APPLICATION_OCTET_STREAM)
}
}
impl Header for ContentType {
fn name() -> &'static HeaderName {
&::http::header::CONTENT_TYPE
}
fn decode<'i, I: Iterator<Item = &'i HeaderValue>>(values: &mut I) -> Result<Self, Error> {
values
.next()
.and_then(|v| v.to_str().ok()?.parse().ok())
.map(ContentType)
.ok_or_else(Error::invalid)
}
fn encode<E: Extend<HeaderValue>>(&self, values: &mut E) {
let value = self
.0
.as_ref()
.parse()
.expect("Mime is always a valid HeaderValue");
values.extend(::std::iter::once(value));
}
}
impl From<mime::Mime> for ContentType {
fn from(m: mime::Mime) -> ContentType {
ContentType(m)
}
}
impl From<ContentType> for mime::Mime {
fn from(ct: ContentType) -> mime::Mime {
ct.0
}
}
impl fmt::Display for ContentType {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
fmt::Display::fmt(&self.0, f)
}
}
impl std::str::FromStr for ContentType {
type Err = Error;
fn from_str(s: &str) -> Result<ContentType, Self::Err> {
s.parse::<Mime>()
.map(|m| m.into())
.map_err(|_| Error::invalid())
}
}
#[cfg(test)]
mod tests {
use super::super::test_decode;
use super::ContentType;
#[test]
fn json() {
assert_eq!(
test_decode::<ContentType>(&["application/json"]),
Some(ContentType::json()),
);
}
#[test]
fn from_str() {
assert_eq!(
"application/json".parse::<ContentType>().unwrap(),
ContentType::json(),
);
assert!("invalid-mimetype".parse::<ContentType>().is_err());
}
bench_header!(bench_plain, ContentType, "text/plain");
bench_header!(bench_json, ContentType, "application/json");
bench_header!(
bench_formdata,
ContentType,
"multipart/form-data; boundary=---------------abcd"
);
}