Rust

Automatically Refresh Token for 401 Unauthorized

See more Google Calendar Examples

Demonstrates how to automatically refresh an access token (without user interaction) when the token expires and a 401 Unauthorized response is received. Rust

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

let token_file_path = "qa_data/tokens/googleCalendar.json".to_string();

// Get our current access token.
let json_token = chilkat::JsonObject::new();
let _ = json_token.load_file(&token_file_path).is_ok();
if !json_token.has_member("access_token") {
    println!("No access token found.");
    return;
}

let http = chilkat::Http::new();
http.set_auth_token(&json_token.string_of("access_token").unwrap_or_default());

let mut json_response = http.quick_get_str("https://www.googleapis.com/calendar/v3/users/me/calendarList").unwrap_or_default();
if !http.last_method_success() {

    if http.last_status() != 401 {
        println!("{}", http.last_error_text());
        println!("----");
        println!("{}", http.last_response_body());
        return;
    }

    // The access token must've expired. 
    // Refresh the access token and then retry the request.
    let oauth2 = chilkat::OAuth2::new();

    oauth2.set_token_endpoint("https://www.googleapis.com/oauth2/v4/token");

    // Replace these with actual values.
    oauth2.set_client_id("GOOGLE-CLIENT-ID");
    oauth2.set_client_secret("GOOGLE-CLIENT-SECRET");

    // Get the "refresh_token"
    oauth2.set_refresh_token(&json_token.string_of("refresh_token").unwrap_or_default());

    // Send the HTTP POST to refresh the access token..
    if oauth2.refresh_access_token().is_err() {
        println!("{}", oauth2.last_error_text());
        return;
    }

    // The response contains a new access token, but we must keep
    // our existing refresh token for when we need to refresh again in the future.
    let _ = json_token.update_string("access_token", &oauth2.access_token());

    // Save the new JSON access token response to a file.
    let sb_json = chilkat::StringBuilder::new();
    json_token.set_emit_compact(false);
    let _ = json_token.emit_sb(&sb_json);
    let _ = sb_json.write_file(&token_file_path, "utf-8", false);

    println!("OAuth2 authorization granted!");
    println!("New Access Token = {}", oauth2.access_token());

    // re-try the original request.
    http.set_auth_token(&oauth2.access_token());
    json_response = http.quick_get_str("https://www.googleapis.com/calendar/v3/users/me/calendarList").unwrap_or_default();
    if !http.last_method_success() {
        println!("{}", http.last_error_text());
        return;
    }

}

println!("{}", json_response);
println!("-----------------------------");