Dart Requires Chilkat v10.1.2+

OAuth2 using an HTTP Proxy (for a Desktop Application)

See more OAuth2 Examples

Shows how to send OAuth2 communications through an HTTP proxy in a desktop application, using Microsoft Graph as an example. This method applies to all OAuth2 applications. Dart

import 'package:chilkat/chilkat.dart';

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

  // To use an HTTP proxy with OAuth2, create a Chilkat socket object and specify the details.
  final socket = CkSocket();
  // Use your HTTP proxy server domain or IP address.
  socket.httpProxyHostname = 'myproxyserver.com';
  // Change this to the listening port of your HTTP proxy server (if necessary)
  socket.httpProxyPort = 808;
  // Specify login/password if needed.
  socket.httpProxyUsername = 'myProxyLogin';
  socket.httpProxyPassword = 'myProxyPassword';
  socket.httpProxyForHttp = true;

  final oauth2 = CkOAuth2();

  // We don't need to connect the socket beforehand.
  // Just tell oauth2 to use the socket which has the HTTP proxy properties.
  oauth2.useConnection(socket);

  // 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.microsoftonline.com/common/oauth2/v2.0/authorize';
  oauth2.tokenEndpoint = 'https://login.microsoftonline.com/common/oauth2/v2.0/token';

  // Replace these with actual values.
  oauth2.clientId = 'MICROSOFT-GRAPH-CLIENT-ID';
  // This is your app password:
  oauth2.clientSecret = 'MICROSOFT-GRAPH-CLIENT-SECRET';

  oauth2.codeChallenge = false;
  // Provide a SPACE separated list of scopes.
  // See https://developer.microsoft.com/en-us/graph/docs/authorization/permission_scopes 

  // Important: To get a refresh token in the final response, you have to ask for "offline_access" scope
  oauth2.scope = 'openid profile offline_access user.readwrite mail.readwrite mail.send files.readwrite';

  // 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:

  // {
  //   "token_type": "Bearer",
  //   "scope": "User.Read Mail.ReadWrite Mail.Send",
  //   "expires_in": 3600,
  //   "ext_expires_in": 0,
  //   "access_token": "EwBAA8l6B...",
  //   "refresh_token": "MCRMdbe...",
  //   "id_token": "eyJ0eXA..."
  // }

  // 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.hasMember('expires_on')) {
    final dtExpire = CkDateTime();
    dtExpire.setFromCurrentSystemTime();
    dtExpire.addSeconds(json.intOf('expires_in'));
    json.appendString('expires_on', dtExpire.getAsUnixTimeStr(false));
  }

  print(json.emit());

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