Request and Response

In this section, we will use the HTTP client to send a request and then convert the received response bytes into a string reference.

Sending an HTTP GET Request

We need to specify what HTTP method we are going to use in the request function, so we will import the Method enum:

#![allow(unused)]
fn main() {
use reqwless::request::Method;
}

Next, inside the fetch_json function, add the following code:

#![allow(unused)]
fn main() {
info!("connecting to {}", &url);

let mut http_request = match http_client.request(Method::GET, url).await {
    Ok(req) => req,
    Err(e) => {
        error!("Failed to make HTTP request: {:?}", e);
        return Err(FetchError::Request);
    }
};
}

With the help of the request method, we prepare an HTTP request. The function takes two arguments: the HTTP method and the request URL. In this example, we create a GET request to httpbin.org. Calling request does not send the request immediately. Instead, it returns a request object that we will send in the next step.

Next, create a receive buffer to store the server’s response, and then send the request:

#![allow(unused)]
fn main() {
let mut rx_buffer = [0; 4096];

let response = match http_request.send(&mut rx_buffer).await {
    Ok(resp) => resp,
    Err(e) => {
        error!("Failed to send HTTP request: {:?}", e);
        return Err(FetchError::Send);
    }
};
}

Finally, we call the send method to transmit the request to the server. If the request completes successfully, it returns a response object that we can use to access the HTTP response returned by the server.

Reading the HTTP Response

Now, let’s continue the fetch_json function and add the following code:

#![allow(unused)]
fn main() {
info!("Response status: {}", response.status.0);

let body_bytes = match response.body().read_to_end().await {
    Ok(b) => b,
    Err(_e) => {
        error!("Failed to read response body");
        return Err(FetchError::ReadBody);
    }
};
}

First, we print the HTTP status code. If the request completed successfully, the status code should be 200. Next, we call the body method to access the response body, and then call the read_to_end method to read the entire response into the body_bytes variable.