Struct Extension

pub struct Extension<T>(pub T);

A middleware that inserts the value into the Extensions during the call.

This is a good way to inject extensions to middleware deeper in the stack

use reqwest::{Client, Request, Response};
use reqwest_middleware::{ClientBuilder, Middleware, Next, Result, Extension};
use http::Extensions;

#[derive(Clone)]
struct LogName(&'static str);
struct LoggingMiddleware;

#[async_trait::async_trait]
impl Middleware for LoggingMiddleware {
    async fn handle(
        &self,
        req: Request,
        extensions: &mut Extensions,
        next: Next<'_>,
    ) -> Result<Response> {
        // get the log name or default to "unknown"
        let name = extensions
            .get()
            .map(|&LogName(name)| name)
            .unwrap_or("unknown");
        println!("[{name}] Request started {req:?}");
        let res = next.run(req, extensions).await;
        println!("[{name}] Result: {res:?}");
        res
    }
}

async fn run() {
    let reqwest_client = Client::builder().build().unwrap();
    let client = ClientBuilder::new(reqwest_client)
        .with_init(Extension(LogName("my-client")))
        .with(LoggingMiddleware)
        .build();
    let resp = client.get("https://truelayer.com").send().await.unwrap();
    println!("TrueLayer page HTML: {}", resp.text().await.unwrap());
}

Tuple Fields

0: T

Trait Implementations

impl<T: Send + Sync + Clone + 'static> RequestInitialiser for Extension<T>

fn init(&self, req: RequestBuilder) -> RequestBuilder