Rust

Refresh HMRC OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to refresh an HMRC access token. Rust

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

// See Get HMRC Access Token 
// for sample code showing how to obtain a HMRC access token for desktop apps.

// It is assumed we previously obtained an OAuth2 access token for HMRC.

let json_token = chilkat::JsonObject::new();
if json_token.load_file("qa_data/tokens/hmrc.json").is_err() {
    println!("Failed to load hmrc.json");
    return;
}

// The access token JSON looks something like this:

// {
//   "token_type": "Bearer",
//   "scope": "user_impersonation",
//   "expires_in": "3599",
//   "ext_expires_in": "0",
//   "expires_on": "1524783438",
//   "not_before": "1524779538",
//   "resource": "https://mydomain.api.crm.dynamics.com",
//   "access_token": "...",
//   "refresh_token": "...",
//   "id_token": "..."
// }

let oauth2 = chilkat::OAuth2::new();

oauth2.set_token_endpoint("https://test-api.service.hmrc.gov.uk/oauth/token");

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

// Load the access token response into the json object 
let _ = json_token.load(&oauth2.access_token_response());

// If an "expires_on" member does not exist, then add the JSON member by
// getting the current system date/time and adding the "expires_in" seconds.
// This way we'll know when the token expires.
if !json_token.has_member("expires_on") {
    let dt_expire = chilkat::DateTime::new();
    let _ = dt_expire.set_from_current_system_time();
    let _ = dt_expire.add_seconds(json_token.int_of("expires_in"));
    let _ = json_token.append_string("expires_on", &dt_expire.get_as_unix_time_str(false).unwrap_or_default());
}

// Save the new JSON access token response to a file.
// The access + refresh tokens contained in this JSON will be needed for the next refresh.
let sb_json = chilkat::StringBuilder::new();
json_token.set_emit_compact(false);
let _ = json_token.emit_sb(&sb_json);
let _ = sb_json.write_file("qa_data/tokens/hmrc.json", "utf-8", false);

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