Rocket/examples/forms/src/main.rs

#![feature(plugin, custom_derive)]
#![plugin(rocket_codegen)]

extern crate rocket;

mod files;

use rocket::response::Redirect;

#[derive(FromForm)]
struct UserLogin<'r> {
    username: &'r str,
    password: &'r str,
    age: Result<isize, &'r str>,
}

#[post("/login", form = "<user>")]
fn login(user: UserLogin) -> Result<Redirect, String> {
    if user.age.is_err() {
        let input = user.age.unwrap_err();
        return Err(format!("'{}' is not a valid age integer.", input));
    }

    let age = user.age.unwrap();
    if age < 20 {
        return Err(format!("Sorry, {} is too young!", age));
    }

    match user.username {
        "Sergio" => match user.password {
            "password" => Ok(Redirect::other("/user/Sergio")),
            _ => Err("Wrong password!".to_string())
        },
        _ => Err(format!("Unrecognized user, '{}'.", user.username))
    }
}

#[post("/user/<username>")]
fn user_page(username: &str) -> String {
    format!("This is {}'s page.", username)
}

fn main() {
    rocket::ignite()
        .mount("/", routes![files::index, files::files, user_page, login])
        .launch();
}