how to use tokio::sync::mpsc::Sender<bool> in State

[alidehghan]

I have the following struct, and wants to use as State in my handler

#[derive(Clone)]
pub(crate) struct CapacityManagerQuestion {
    pub(crate) tenant_code: String,
    pub(crate) user_ip: String,
    pub(crate) answer: mpsc::Sender<bool>,
}

my handler is:

pub(crate) async fn get_banner(State(state):State<Sender<CapacityManagerQuestion>>, mut req : Request) -> Result<Response, StatusCode>  {}

and my sever is :

let app = Router::new()
    .route("/{*wildcard}",  get(handlers::get_banner))
    .with_state(self.capacity_manager_question_channel.clone());

axum::serve(listener, app).await.unwrap();

and got this error:

error[E0277]: `Serve<tokio::net::TcpListener, axum::Router<tokio::sync::mpsc::Sender<CapacityManagerQuestion>>, _>` is not a future

could you please help me?

[alidehghan]

for those people like me, wondering this exotic behaviors, just put with_state at the end of lines of Router....

following code makes error:

    let app = Router::new()
                .route("/{*wildcard}", get(handlers::get_banner).post(handlers::process))
         ->>>        .with_state(self.capacity_manager_question_channel.clone());
                .fallback(get(handlers::get_banner));

while following code is ok !!!

    let app = Router::new()
                .route("/{*wildcard}", get(handlers::get_banner).post(handlers::process))
                .fallback(get(handlers::get_banner))
   ->>>            .with_state(self.capacity_manager_question_channel.clone());

yes, that is 4-hour searching!!! nothing documented in axum state website! thanks axum guys for such beautiful coding.

[Turbo87]

yes, that is 4-hour searching!!! nothing documented in axum state website!

https://docs.rs/axum/latest/axum/#using-the-state-extractor has with_state() right in the first code snippet.

also, https://docs.rs/axum/latest/axum/extract/struct.State.html#combining-stateful-routers says:

In short, a Router’s generic state type defaults to () (no state) unless Router::with_state is called or the value of the generic type is given explicitly.

[alidehghan]

you misunderstood the issue, dude. the problem is not document about how to use state (which you pointed in your reply), the point is order of using state at router which cause exotic bugs (and rust compiler doesn't tell anything useful regarding that).

It is better to mention this issue on documents in a very bold highlighted notation (to prevent developers from searching whole the world)