Struct AcceptHeader 

pub struct AcceptHeader {
    pub items: Vec<AcceptItem>,
}

Parsed Accept header with quality-ordered media types.

This extractor parses the Accept header and provides the list of acceptable media types sorted by quality (highest first).

Example

use fastapi_core::AcceptHeader;

async fn handler(accept: AcceptHeader) -> impl IntoResponse {
    if accept.prefers("application/json") {
        Json(data).into_response()
    } else if accept.prefers("text/html") {
        Html(template).into_response()
    } else {
        // Default to JSON
        Json(data).into_response()
    }
}

Fields

items: Vec<AcceptItem>

Media types sorted by quality (highest first).

Implementations

impl AcceptHeader

pub fn parse(s: &str) -> Self

Parse an Accept header value.

Example

let accept = AcceptHeader::parse("text/html, application/json;q=0.9, */*;q=0.1");
assert_eq!(accept.items.len(), 3);
assert_eq!(accept.items[0].media_type.subtype, "html"); // q=1.0
assert_eq!(accept.items[1].media_type.subtype, "json"); // q=0.9

pub fn any() -> Self

Create an AcceptHeader that accepts anything.

pub fn accepts(&self, media_type: &str) -> bool

Check if a media type is acceptable.

pub fn prefers(&self, media_type: &str) -> bool

Check if a media type is the preferred type.

Returns true if the given media type matches the highest-quality acceptable type.

pub fn quality_of(&self, media_type: &str) -> f32

Get the quality value for a specific media type.

Returns 0.0 if not acceptable, or the quality value if acceptable.

pub fn negotiate<'a>(&self, available: &[&'a str]) -> Option<&'a str>

Negotiate the best media type from a list of available types.

Returns the first available type that is acceptable, preferring higher quality matches.

Example

let accept = AcceptHeader::parse("text/html, application/json;q=0.9");
let available = ["application/json", "text/html", "text/plain"];
let best = accept.negotiate(&available);
assert_eq!(best, Some("text/html"));

pub fn is_empty(&self) -> bool

Check if the Accept header is empty (accepts anything).

Trait Implementations

impl Clone for AcceptHeader

fn clone(&self) -> AcceptHeader

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AcceptHeader

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for AcceptHeader

fn default() -> Self

Returns the “default value” for a type.

impl FromRequest for AcceptHeader

type Error = Infallible

Error type when extraction fails.

async fn from_request( _ctx: &RequestContext, req: &mut Request, ) -> Result<Self, Self::Error>

Extract a value from the request.