Rust

Get a Google People API OAuth2 Access Token

See more Google People Examples

Demonstrates how to get a Google People OAuth2 access token from a desktop application or script. Rust

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

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

// For Google OAuth2, set the ListenPort equal to the port specified in the authorized callback URI for the ClientID.
// See http://cknotes.com/setup-google-account-for-google-drive-api-walkthrough/
oauth2.set_listen_port(3017);

oauth2.set_authorization_endpoint("https://accounts.google.com/o/oauth2/v2/auth");
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");

oauth2.set_code_challenge(true);
oauth2.set_code_challenge_method("S256");

// See Google People API Scopes for more scopes.
oauth2.set_scope("profile https://www.googleapis.com/auth/contacts https://www.googleapis.com/auth/contacts.other.readonly https://www.googleapis.com/auth/directory.readonly");

// Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
let Ok(url) = oauth2.start_auth() else {
    println!("{}", oauth2.last_error_text());
    return;
};

// Launch the system's default browser navigated to the URL.
if oauth2.launch_browser(&url).is_err() {
    println!("{}", oauth2.last_error_text());
    return;
}

// Now wait for the authorization.
// We'll wait for a max of 30 seconds.
let mut num_ms_waited = 0;
while (num_ms_waited < 30000) && (oauth2.auth_flow_state() < 3) {
    oauth2.sleep_ms(100);
    num_ms_waited = num_ms_waited + 100;
}

// If there was no response from the browser within 30 seconds, then 
// the AuthFlowState will be equal to 1 or 2.
// 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
// 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
// In that case, cancel the background task started in the call to StartAuth.
if oauth2.auth_flow_state() < 3 {
    let _ = oauth2.cancel();
    println!("No response from the browser!");
    return;
}

// Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
// The possible AuthFlowState values are:
// 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
// 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
// 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
if oauth2.auth_flow_state() == 5 {
    println!("OAuth2 failed to complete.");
    println!("{}", oauth2.failure_info());
    return;
}

if oauth2.auth_flow_state() == 4 {
    println!("OAuth2 authorization was denied.");
    println!("{}", oauth2.access_token_response());
    return;
}

if oauth2.auth_flow_state() != 3 {
    println!("Unexpected AuthFlowState:{}", oauth2.auth_flow_state());
    return;
}

// Save the full JSON access token response to a file.
let sb_json = chilkat::StringBuilder::new();
let _ = sb_json.append(&oauth2.access_token_response());
let _ = sb_json.write_file("qa_data/tokens/googlePeople.json", "utf-8", false);

// The saved JSON response looks like this:

// {
//   "access_token": "ya29.a0AfH6S ... LAZYFUkf0",
//   "expires_in": 3599,
//   "refresh_token": "1//0fL_Ov ... ee0",
//   "scope": "https://www.googleapis.com/auth/contacts",
//   "token_type": "Bearer"
// }

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