Catcher

If the status code of Response is an error, and the Body in the page is empty, salvo will try to use Catcher to catch the error and display a friendly error page.

You can return a system default Catcher through Catcher::default(), and then add it to Service.

use salvo::catcher::Catcher;

Service::new(router).catcher(Catcher::default());

The default Catcher supports sending error pages in XML, JSON, HTML, Text formats.

You can add a custom error catcher to Catcher by adding hoop to the default Catcher. This error catcher is still a Handler.

You can add multiple custom error catchers to Catcher through hoop. Custom error handlers can be called after handling errors. FlowCtrl::skip_next method skips the subsequent error program and returns early.

use salvo::catcher::Catcher;
use salvo::prelude::*;

#[handler]
async fn hello() -> &'static str {
    "Hello World"
}
#[handler]
async fn error500(res: &mut Response) {
    res.status_code(StatusCode::INTERNAL_SERVER_ERROR);
}

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt().init();

    let acceptor = TcpListener::new("127.0.0.1:5800").bind().await;
    Server::new(acceptor).serve(create_service()).await;
}

fn create_service() -> Service {
    let router = Router::new()
        .get(hello)
        .push(Router::with_path("500").get(error500));
    Service::new(router).catcher(Catcher::default().hoop(handle404))
}

#[handler]
async fn handle404(res: &mut Response, ctrl: &mut FlowCtrl) {
    if StatusCode::NOT_FOUND == res.status_code.unwrap_or(StatusCode::NOT_FOUND) {
        res.render("Custom 404 Error Page");
        ctrl.skip_rest();
    }
}

[package]
name = "example-custom-error-page"
version = "0.1.0"
edition = "2021"
publish = false


[dependencies]
salvo.workspace = true
tokio = { version = "1", features = ["macros"] }
tracing = "0.1"
tracing-subscriber = "0.3"