• English

      • Session

      Middleware providing support for Session.

      What is Session

      Session refers to user data stored on the server side, typically used to track user state and store temporary data. In web applications, Session addresses the stateless nature of the HTTP protocol, enabling the server to recognize multiple requests from the same user.

      Using Session in Salvo

      In Salvo, the Session middleware offers a simple API for reading and writing session data. The SessionDepot can be used to obtain a session instance, while methods such as get, set, and remove allow for managing session data.

      Common Use Cases

      • User authentication and login state management
      • Temporary storage of form data
      • Storage of user preference settings

      Example Code

      main.rs
      Cargo.toml
      use salvo::prelude::*;
use salvo::session::{CookieStore, Session, SessionDepotExt, SessionHandler};

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt().init();
    let session_handler = SessionHandler::builder(
        CookieStore::new(),
        b"secretabsecretabsecretabsecretabsecretabsecretabsecretabsecretab",
    )
    .build()
    .unwrap();
    let router = Router::new()
        .hoop(session_handler)
        .get(home)
        .push(Router::with_path("login").get(login).post(login))
        .push(Router::with_path("logout").get(logout));

    let acceptor = TcpListener::new("0.0.0.0:8698").bind().await;
    Server::new(acceptor).serve(router).await;
}

#[handler]
pub async fn login(req: &mut Request, depot: &mut Depot, res: &mut Response) {
    if req.method() == salvo::http::Method::POST {
        let mut session = Session::new();
        session
            .insert("username", req.form::<String>("username").await.unwrap())
            .unwrap();
        depot.set_session(session);
        res.render(Redirect::other("/"));
    } else {
        res.render(Text::Html(LOGIN_HTML));
    }
}

#[handler]
pub async fn logout(depot: &mut Depot, res: &mut Response) {
    if let Some(session) = depot.session_mut() {
        session.remove("username");
    }
    res.render(Redirect::other("/"));
}

#[handler]
pub async fn home(depot: &mut Depot, res: &mut Response) {
    let mut content = r#"<a href="login">Login</h1>"#.into();
    if let Some(session) = depot.session_mut()
        && let Some(username) = session.get::<String>("username")
    {
        content = format!(r#"Hello, {username}. <br><a href="logout">Logout</h1>"#);
    }
    res.render(Text::Html(content));
}

static LOGIN_HTML: &str = r#"<!DOCTYPE html>
<html>
    <head>
        <title>Login</title>
    </head>
    <body>
        <form action="/login" method="post">
            <h1>Login</h1>
            <input type="text" name="username" />
            <button type="submit" id="submit">Submit</button>
        </form>
    </body>
</html>
"#;