Session
Middleware that provides Session support.
What is a Session
A Session is a piece of user data stored on the server-side, typically used to track user status and save temporary data. In web applications, Sessions solve the stateless nature of the HTTP protocol, allowing the server to recognize multiple requests from the same user.
Using Sessions in Salvo
In Salvo, the Session middleware provides a simple API to read and write session data. You can obtain a session instance via SessionDepot, and manage session data using methods like get, set, and remove.
Common Use Cases
- User authentication and login status management
- Temporary storage of form data
- Storage of user preferences
Example Code
session-login/src/main.rs
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("0.0.0.0:5800").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() {
if 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>
"#;
