Dart Requires Chilkat v10.1.2+

Adobe Sign OAuth2 Access Token

See more OAuth2 Examples

Demonstrates how to get an Adobe Sign OAuth2 access token from a desktop application or script. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // To further clarify, see OAuth 2.0 Authorization Flow

  final oauth2 = CkOAuth2();

  // The Adobe Sign OAuth2 requires an "https" callback URL.  This means the "http://localhost:<portNumber>/" is not possible.
  // For a desktop app, you must provide a script on your web server to redirect to "http://localhost:<portNumber>/"

  // See Using Your Web Server as an Intermediary for OAuth2 Redirect to localhost

  oauth2.appCallbackUrl = 'https://yourwebserver.com/OAuth2.php';
  oauth2.listenPort = 3017;

  oauth2.authorizationEndpoint = 'https://secure.na2.echosign.com/public/oauth';
  oauth2.tokenEndpoint = 'https://api.na2.echosign.com/oauth/token';

  // Replace these with actual values.
  oauth2.clientId = 'MY_CLIENT_ID';

  // This is for Require Proof Key for Code Exchange (PKCE)
  // See OAuth2 PKCE Explained
  oauth2.codeChallenge = true;
  oauth2.codeChallengeMethod = 'S256';

  // Indicate the desired access by listing scopes.
  oauth2.scope = 'user_read agreement_read workflow_read';

  // 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;
  }

  // Save the full JSON access token response to a file.
  final sbJson = CkStringBuilder();
  sbJson.append(oauth2.accessTokenResponse);
  sbJson.writeFile('qa_data/tokens/adobe-sign-access-token.json', 'utf-8', false);

  // The full JSON received looks like this:
  // {
  //   "access_token": "3AAABL ... YCpUu",
  //   "refresh_token": "3AAABL ... tpDs0*",
  //   "token_type": "Bearer",
  //   "expires_in": 3600
  // }

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