Warp | 06 , Query Parameter

Let’s add query parameters to a route path .

(**Youtube Video**)

In cargo.toml :

[dependencies]
tokio = { version = "1", features = ["full"] }
warp = { version = "0.4", features = ["server"] }

serde = { version = "1.0", features = ["derive"] }

We need serde to deserialize json .

In main.rs :

use serde::Deserialize;
use warp::{Filter};

#[tokio::main]
async fn main() {
    let app = app();

    warp::serve(app)
        .run(([0,0,0,0], 3000))
        .await;
}

fn app() -> impl Filter<Extract = impl warp::Reply, Error = warp::Rejection> + Clone {
    let root = warp::path!().map(|| "Home!");

    let hello = warp::get().and(warp::path!("hello" / i32)).and(warp::query::<Person>()).and_then(hello_handler);

    root
        .or(hello)
}

async fn hello_handler (id: i32, person: Person) -> Result<String , warp::Rejection> {
    Ok(format!("Hello  {}, your id is {} , your age is {}", person.name, id, person.age))
}

#[derive(Deserialize)]
struct Person {
    name: String,
    age: i32
}

In the hello route, we use the and method to attach query parameters. Inside that and call, we use the query function together with the turbo-fish syntax to specify the type Person, which is the struct we defined.

To access the query values, the hello_handler function simply takes a parameter named person of type Person. Warp automatically deserializes the query string into this struct.

So when we visit http://localhost:3000/hello/2?name=jim&age=20, the response will be: “Hello jim, your id is 2, your age is 20.”