Dart Requires Chilkat v10.1.2+

Twinfield OAuth2 for Desktop App or Script

See more OAuth2 Examples

Demonstrates how to get a Twinfield OAuth2 access token from a desktop application or script. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // For more information about the OAuth2, see OAuth 2.0 Authorization Flow

  final oauth2 = CkOAuth2();

  // This should be the port in the localhost callback URL for your app.  
  // The callback URL would look like "http://localhost:3017/" if the port number is 3017.
  oauth2.listenPort = 3017;

  oauth2.authorizationEndpoint = 'https://login.twinfield.com/auth/authentication/connect/authorize';
  oauth2.tokenEndpoint = 'https://login.twinfield.com/auth/authentication/connect/token';

  // Replace these with actual values.
  oauth2.clientId = 'CLIENT_ID';
  oauth2.clientSecret = 'CLIENT_SECRET';

  oauth2.scope = 'openid twf.user twf.organisation twf.organisationUser offline_access';

  oauth2.codeChallenge = true;
  oauth2.codeChallengeMethod = 'S256';

  // Twinfield requires that the request to exchange the authorization code for a token must be a GET.
  // (In most cases, OAuth2 is implemented where the exchange for token HTTP request is a POST.)
  // Note: The exchange-for-token happens within Chilkat in a background thread.  After the user interactively 
  // accepts or denies authorization, the browser receives the response and redirects to localhost:<port>,
  // where Chilkat is waiting on a background thread to receive the redirect, process it, and then send the HTTP request
  // to exchange the code for a token.  This happens internally while your code below is waiting for the authorization..)
  oauth2.uncommonOptions = 'EXCHANGE_CODE_FOR_TOKEN_USING_GET';

  // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
  final String url;
  try {
    url = oauth2.startAuth();
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('url = $url');

  // Launch the default browser on the system and navigate to the url.
  // The LaunchBrowser method was added in Chilkat v10.1.2.
  try {
    oauth2.launchBrowser(url);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Wait for the user to approve or deny authorization in the browser.
  var numMsWaited = 0;
  while ((numMsWaited < 90000) && (oauth2.authFlowState < 3)) {
    oauth2.sleepMs(100);
    numMsWaited += 100;
  }

  // If the browser does not respond within the specified time, AuthFlowState will be:
  // 
  // 1: Waiting for Redirect - The OAuth2 background thread is waiting for the browser's redirect request.
  // 2: Waiting for Final Response - The thread is awaiting the final access token response.
  // In either case, cancel the background task initiated by StartAuth.

  if (oauth2.authFlowState < 3) {
    oauth2.cancel();
    print('No response from the browser!');
    return;
  }

  // Check AuthFlowState to determine if authorization was granted, denied, or failed:
  // 
  // 3: Success - OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
  // 4: Access Denied - OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
  // 5: Failure - OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

  if (oauth2.authFlowState == 5) {
    print('OAuth2 failed to complete.');
    print(oauth2.failureInfo);
    return;
  }

  if (oauth2.authFlowState == 4) {
    print('OAuth2 authorization was denied.');
    print(oauth2.accessTokenResponse);
    return;
  }

  if (oauth2.authFlowState != 3) {
    print('Unexpected AuthFlowState:${oauth2.authFlowState}');
    return;
  }

  print('OAuth2 authorization granted!');
  print('Access Token = ${oauth2.accessToken}');

  // Get the full JSON response:
  final json = CkJsonObject();
  json.load(oauth2.accessTokenResponse);
  json.emitCompact = false;

  // The JSON response looks like this:

  print(json.emit());

  // Save the JSON to a file for future requests.
  final fac = CkFileAccess();
  fac.writeEntireTextFile('qa_data/tokens/twinfield.json', json.emit(), 'utf-8', false);
}