Trait poem::web::FromRequest

source ·

pub trait FromRequest<'a>: Sized {
    // Required method
    fn from_request(
        req: &'a Request,
        body: &mut RequestBody
    ) -> impl Future<Output = Result<Self>> + Send;

    // Provided method
    fn from_request_without_body(
        req: &'a Request
    ) -> impl Future<Output = Result<Self>> + Send { ... }
}

Expand description

Represents an type that can be extract from requests.

§Provided Implementations

Option<T>

Extracts T from the incoming request, returns None if it fails.
&Request

Extracts the Request from the incoming request.
&RemoteAddr

Extracts the remote peer’s address RemoteAddr from request.
&LocalAddr

Extracts the local server’s address LocalAddr from request.
RealIp

Extracts the remote peer’s real ip address from request.
Method

Extracts the Method from the incoming request.
Version

Extracts the Version from the incoming request.
&Uri

Extracts the Uri from the incoming request.
&HeaderMap

Extracts the HeaderMap from the incoming request.
Data<&T>

Extracts the Data from the incoming request.
TypedHeader<T>

Extracts the TypedHeader from the incoming request.
Path<T>

Extracts the Path from the incoming request.
Query<T>

Extracts the Query from the incoming request.
Form<T>

Extracts the Form from the incoming request.
Json<T>

Extracts the Json from the incoming request.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
Xml<T>

Extracts the Xml from the incoming request.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
TempFile

Extracts the TempFile from the incoming request.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
Multipart

Extracts the Multipart from the incoming request.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
&CookieJar

Extracts the CookieJar from the incoming request.

Requires CookieJarManager middleware.
&Session

Extracts the Session from the incoming request.

Requires CookieSession or RedisSession middleware.
Body

Extracts the Body from the incoming request.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
String

Extracts the body from the incoming request and parse it into utf8 String.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
Vec<u8>

Extracts the body from the incoming request and collect it into Vec<u8>.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
Bytes

Extracts the body from the incoming request and collect it into Bytes.

This extractor will take over the requested body, so you should avoid using multiple extractors of this type in one handler.
WebSocket

Ready to accept a websocket WebSocket connection.
Locale

Extracts the Locale from the incoming request.
StaticFileRequest

Ready to accept a static file request StaticFileRequest.
Accept

Extracts the Accept header from the incoming request.
PathPattern

Extracts the matched path pattern from the incoming request.

§Create your own extractor

The following is an example of a custom token extractor, which extracts the token from the MyToken header.

use std::fmt::{self, Display, Formatter};

use poem::{
    get, handler, http::StatusCode, test::TestClient, Endpoint, Error, FromRequest, Request,
    RequestBody, Result, Route,
};

struct Token(String);

impl<'a> FromRequest<'a> for Token {
    async fn from_request(req: &'a Request, body: &mut RequestBody) -> Result<Self> {
        let token = req
            .headers()
            .get("MyToken")
            .and_then(|value| value.to_str().ok())
            .ok_or_else(|| Error::from_string("missing token", StatusCode::BAD_REQUEST))?;
        Ok(Token(token.to_string()))
    }
}

#[handler]
async fn index(token: Token) {
    assert_eq!(token.0, "token123");
}

let app = Route::new().at("/", get(index));
let cli = TestClient::new(app);

cli.get("/")
    .header("MyToken", "token123")
    .send()
    .await
    .assert_status_is_ok();

Required Methods§

source

fn from_request( req: &'a Request, body: &mut RequestBody ) -> impl Future<Output = Result<Self>> + Send

Extract from request head and body.

Provided Methods§

source

fn from_request_without_body( req: &'a Request ) -> impl Future<Output = Result<Self>> + Send

Extract from request head.

If you know that this type does not need to extract the body, then you can just use it.

For example Query, Path they only extract the content from the request head, using this method would be more convenient. String,Vec<u8> they extract the body of the request, using this method will cause ReadBodyError error.