actix-state-guards

This crate provides a more flexible guard function for the actix-web framework.

The Guard acts as a gatekeeper for a specific scope and governs over which request is allowed to pass.

Guards can accept application state as well as types that implement the FromReqeust trait as parameters. They can also execute asynchrones code inside them.

Example

#[derive(Debug)]
pub struct CounterError();

impl Display for CounterError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str("Error: Counter is over 100")
    }
}

impl ResponseError for CounterError {}

#[get("/count")]
async fn count(counter: web::Data<Mutex<u32>>) -> impl Responder {
    let mut counter = counter.lock().unwrap();
    *counter += 1;
    counter.to_string()
}

#[actix_web::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    Ok(HttpServer::new(move || {
        App::new()
            .app_data(web::Data::new(Mutex::new(0u32)))
            .use_state_guard(
                |counter: web::Data<Mutex<u32>>| async move {
                    if *counter.lock().unwrap() < 100 {
                        Ok(())
                    } else {
                        // by returning the error case of the result enum we signal that this
                        // request shall not be allowed to pass on to the scope wrapped
                        Err(CounterError())
                    }
                },
                web::scope("").service(count),
            )
    })
    .bind(("127.0.0.1", 8080))?
    .run()
    .await?)
}

License: MIT