Reqwest - 30th of July

Needed to run async code:

cargo add tokio -F full

No worries. Tokio will be explained in the next weeks. For now you only need to know we need an async runtime, that runs our async code.

cargo add reqwest

Is an easy to use http client for Rust.

How to use it

Below snippet will fetch the HTML from Google and print it to the console.

#[tokio::main]
async fn main() {
    let html_from_google = reqwest::get("https://www.google.com")
        .await
        .unwrap()
        .text()
        .await
        .unwrap();

    println!("{html_from_google}")
}

The example lives in reqwest-crate directory. To run it, use

cargo run --bin simple

How it's normally used

You can also combine serde with reqwest to deserialize JSON responses when fetching data, or serialize data, if you want to send data to a server.

cargo add serde -F derive
cargo add reqwest -F json

Getting data

use serde::Deserialize;

const URL: &str = "https://pokeapi.co/api/v2/pokemon";

#[derive(Deserialize, Debug)]
struct Pokemon {
    name: String,
    height: u32,
}

#[tokio::main]
async fn main() {
    let pokename = "bulbasaur";
    let url_with_endpoint = format!("{}/{}", URL, pokename);
    let pokemon: Pokemon = reqwest::get(url_with_endpoint) // << will get the response
        .await
        .unwrap() // << will crash, if we have an error fetching the data
        .json() // << will deserialize the response body into a Pokemon struct
        .await
        .unwrap(); // << will crash, if we have an error deserializing the data

    println!("{pokemon:?}")
}

You can run this example by running (from reqwest-crate directory)

cargo run --bin with_json

It should print something like this:

Pokemon { name: "bulbasaur", height: 7 }

More sophisticated things

You can also utilize reqwest's builders to create more complex requests.

#![allow(unused)]
fn main() {
// This will POST a body of `foo=bar&baz=quux`
let params = [("foo", "bar"), ("baz", "quux")];
let client = reqwest::Client::new();
let res = client.post("http://httpbin.org/post")
    .form(&params)
    .send()
    .await?;
}

This will send a form to the given URL.

See reqwest for more.