How to access SocketIO state in axum handler?

[fra-luc]

Hi 👋 😃
Plenty of examples in the repo show how access the SocketIO state in a socketioxide handler but...
given this example, how would I access the SocketIO state (messages) within the axum handler function?

use axum::routing::post;
use socketioxide::{
    extract::{Data, SocketRef, State},
    SocketIo,
};
use tokio::net::TcpListener;
use tower::ServiceBuilder;
use tower_http::cors::CorsLayer;
use tracing::info;
use tracing_subscriber::FmtSubscriber;


async fn handler(axum::extract::State(io): axum::extract::State<SocketIo>) {
    // HOW TO EXTRACT SOCKETIO STATE i.e. message?
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let messages = state::MessageStore::default();

    let (layer, io) = SocketIo::builder().with_state(messages).build_layer();

    let app = axum::Router::new()
        .route("/", post(handler))
        .with_state(io)
        .layer(
            ServiceBuilder::new()
            .layer(layer),
        );

    info!("Starting server");

    let listener = TcpListener::bind("0.0.0.0:3000").await.unwrap();
    axum::serve(listener, app).await.unwrap();

    Ok(())
}

Thank you for your help and also for the really cool crate!
Keep in mind that I'm a rust newbie 😁 ❤️

[Totodore]

Hi ! You have to wrap your state in an Arc<T> so that it is cheaply cloneable and that you have a reference in the state anywhere (it is required by axum and will soon be required by socketioxide also).
Then you can either create your own axum State struct and put your socket.io Arc<SocketIoState> in it or you can directly use the state you set for socket.io as an axum state:

Here is an example with a custom State structs that wraps store::Messages and SocketIo.

use axum::routing::post;
use socketioxide::{
    extract::{Data, SocketRef, State},
    SocketIo,
};
use tokio::net::TcpListener;
use tower::ServiceBuilder;
use tower_http::cors::CorsLayer;
use tracing::info;
use tracing_subscriber::FmtSubscriber;

#[derive(Clone)]
struct State {
    messages: Arc<state::MessageStore>,
    io: SocketIo,
}

async fn handler(axum::extract::State(State { messages, ..  }): axum::extract::State<State>) {
  dbg!(&messages); // You can use message store here !
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let messages = Arc::new(state::MessageStore::default());

    let (layer, io) = SocketIo::builder().with_state(messages).build_layer();
    let state = State {
        messages,
        io,
    };

    let app = axum::Router::new()
        .route("/", post(handler))
        .with_state(state)
        .layer(
            ServiceBuilder::new()
            .layer(layer),
        );

    info!("Starting server");

    let listener = TcpListener::bind("0.0.0.0:3000").await.unwrap();
    axum::serve(listener, app).await.unwrap();

    Ok(())
}

[fra-luc]

Thank you very much! ❤️
I'll give this a try soon and get back to you 😉