Trait axum::extract::FromRequest[−][src]

pub trait FromRequest<B = Body>: Sized {
    type Rejection: IntoResponse;
    fn from_request<'life0, 'async_trait>(
        req: &'life0 mut RequestParts<B>
    ) -> Pin<Box<dyn Future<Output = Result<Self, Self::Rejection>> + Send + 'async_trait>>
    where
        'life0: 'async_trait,
        Self: 'async_trait;
}
Expand description

Types that can be created from requests.

See the module docs for more details.

What is the B type parameter?

FromRequest is generic over the request body (the B in http::Request<B>). This is to allow FromRequest to be usable will any type of request body. This is necessary because some middleware change the request body, for example to add timeouts.

If you’re writing your own FromRequest that wont be used outside your application, and not using any middleware that changes the request body, you can most likely use axum::body::Body. Note this is also the default.

If you’re writing a library, thats intended for others to use, its recommended to keep the generic type parameter:

use axum::{
    async_trait,
    extract::{FromRequest, RequestParts},
};

struct MyExtractor;

#[async_trait]
impl<B> FromRequest<B> for MyExtractor
where
    B: Send, // required by `async_trait`
{
    type Rejection = http::StatusCode;

    async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
        // ...
    }
}

This ensures your extractor is as flexible as possible.

Associated Types

If the extractor fails it’ll use this “rejection” type. A rejection is a kind of error that can be converted into a response.

Required methods

Perform the extraction.

Implementations on Foreign Types

[src]

impl FromRequest<Body> for Body

Implementors