Function warp::filters::path::param

source · [−]
pub fn param<T: FromStr + Send + 'static>(
) -> impl Filter<Extract = (T,), Error = Rejection> + Copy
Expand description

Extract a parameter from a path segment.

This will try to parse a value from the current request path segment, and if successful, the value is returned as the Filter’s “extracted” value.

If the value could not be parsed, rejects with a 404 Not Found.

Example

use warp::Filter;

let route = warp::path::param()
    .map(|id: u32| {
        format!("You asked for /{}", id)
    });
Examples found in repository?
examples/dyn_reply.rs (line 14)
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async fn main() {
    let routes = warp::path::param().and_then(dyn_reply);

    warp::serve(routes).run(([127, 0, 0, 1], 3030)).await;
}
More examples
Hide additional examples
examples/futures.rs (line 11)
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async fn main() {
    // Match `/:Seconds`...
    let routes = warp::path::param()
        // and_then create a `Future` that will simply wait N seconds...
        .and_then(sleepy);

    warp::serve(routes).run(([127, 0, 0, 1], 3030)).await;
}
examples/body.rs (line 20)
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async fn main() {
    pretty_env_logger::init();

    // POST /employees/:rate  {"name":"Sean","rate":2}
    let promote = warp::post()
        .and(warp::path("employees"))
        .and(warp::path::param::<u32>())
        // Only accept bodies smaller than 16kb...
        .and(warp::body::content_length_limit(1024 * 16))
        .and(warp::body::json())
        .map(|rate, mut employee: Employee| {
            employee.rate = rate;
            warp::reply::json(&employee)
        });

    warp::serve(promote).run(([127, 0, 0, 1], 3030)).await
}
examples/sse_chat.rs (line 24)
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async fn main() {
    pretty_env_logger::init();

    // Keep track of all connected users, key is usize, value
    // is an event stream sender.
    let users = Arc::new(Mutex::new(HashMap::new()));
    // Turn our "state" into a new Filter...
    let users = warp::any().map(move || users.clone());

    // POST /chat -> send message
    let chat_send = warp::path("chat")
        .and(warp::post())
        .and(warp::path::param::<usize>())
        .and(warp::body::content_length_limit(500))
        .and(
            warp::body::bytes().and_then(|body: bytes::Bytes| async move {
                std::str::from_utf8(&body)
                    .map(String::from)
                    .map_err(|_e| warp::reject::custom(NotUtf8))
            }),
        )
        .and(users.clone())
        .map(|my_id, msg, users| {
            user_message(my_id, msg, &users);
            warp::reply()
        });

    // GET /chat -> messages stream
    let chat_recv = warp::path("chat").and(warp::get()).and(users).map(|users| {
        // reply using server-sent events
        let stream = user_connected(users);
        warp::sse::reply(warp::sse::keep_alive().stream(stream))
    });

    // GET / -> index html
    let index = warp::path::end().map(|| {
        warp::http::Response::builder()
            .header("content-type", "text/html; charset=utf-8")
            .body(INDEX_HTML)
    });

    let routes = index.or(chat_recv).or(chat_send);

    warp::serve(routes).run(([127, 0, 0, 1], 3030)).await;
}
examples/routing.rs (line 50)
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async fn main() {
    pretty_env_logger::init();

    // We'll start simple, and gradually show how you combine these powers
    // into super powers!

    // GET /
    let hello_world = warp::path::end().map(|| "Hello, World at root!");

    // GET /hi
    let hi = warp::path("hi").map(|| "Hello, World!");

    // How about multiple segments? First, we could use the `path!` macro:
    //
    // GET /hello/from/warp
    let hello_from_warp = warp::path!("hello" / "from" / "warp").map(|| "Hello from warp!");

    // Fine, but how do I handle parameters in paths?
    //
    // GET /sum/:u32/:u32
    let sum = warp::path!("sum" / u32 / u32).map(|a, b| format!("{} + {} = {}", a, b, a + b));

    // Any type that implements FromStr can be used, and in any order:
    //
    // GET /:u16/times/:u16
    let times =
        warp::path!(u16 / "times" / u16).map(|a, b| format!("{} times {} = {}", a, b, a * b));

    // Oh shoot, those math routes should be mounted at a different path,
    // is that possible? Yep.
    //
    // GET /math/sum/:u32/:u32
    // GET /math/:u16/times/:u16
    let math = warp::path("math");
    let _sum = math.and(sum);
    let _times = math.and(times);

    // What! And? What's that do?
    //
    // It combines the filters in a sort of "this and then that" order. In
    // fact, it's exactly what the `path!` macro has been doing internally.
    //
    // GET /bye/:string
    let bye = warp::path("bye")
        .and(warp::path::param())
        .map(|name: String| format!("Good bye, {}!", name));

    // Ah, can filters do things besides `and`?
    //
    // Why, yes they can! They can also `or`! As you might expect, `or` creates
    // a "this or else that" chain of filters. If the first doesn't succeed,
    // then it tries the other.
    //
    // So, those `math` routes could have been mounted all as one, with `or`.
    //
    // GET /math/sum/:u32/:u32
    // GET /math/:u16/times/:u16
    let math = warp::path("math").and(sum.or(times));

    // We can use the end() filter to match a shorter path
    let help = warp::path("math")
        // Careful! Omitting the following line would make this filter match
        // requests to /math/sum/:u32/:u32 and /math/:u16/times/:u16
        .and(warp::path::end())
        .map(|| "This is the Math API. Try calling /math/sum/:u32/:u32 or /math/:u16/times/:u16");
    let math = help.or(math);

    // Let's let people know that the `sum` and `times` routes are under `math`.
    let sum = sum.map(|output| format!("(This route has moved to /math/sum/:u16/:u16) {}", output));
    let times =
        times.map(|output| format!("(This route has moved to /math/:u16/times/:u16) {}", output));

    // It turns out, using `or` is how you combine everything together into
    // a single API. (We also actually haven't been enforcing that the
    // method is GET, so we'll do that too!)
    //
    // GET /
    // GET /hi
    // GET /hello/from/warp
    // GET /bye/:string
    // GET /math/sum/:u32/:u32
    // GET /math/:u16/times/:u16

    let routes = warp::get().and(
        hello_world
            .or(hi)
            .or(hello_from_warp)
            .or(bye)
            .or(math)
            .or(sum)
            .or(times),
    );

    // Note that composing filters for many routes may increase compile times (because it uses a lot of generics).
    // If you wish to use dynamic dispatch instead and speed up compile times while
    // making it slightly slower at runtime, you can use Filter::boxed().

    warp::serve(routes).run(([127, 0, 0, 1], 3030)).await;
}