Dart

Dropbox Refresh OAuth2 Access Token

See more Dropbox Examples

Demonstrates how to mint a new access token using the refresh token obtained when originally getting the OAuth2 access token. Dart

import 'package:chilkat/chilkat.dart';

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

  final http = CkHttp();

  // Implements the following CURL command:

  // curl -X GET https://api.dropbox.com/oauth2/token \
  //     -d grant_type=refresh_token \
  //     -d refresh_token=<YOUR_REFRESH_TOKEN> \
  //     -u <YOUR_APP_KEY>:<YOUR_APP_SECRET>

  // Use the following online tool to generate HTTP code from a CURL command
  // Convert a cURL Command to HTTP Source Code

  http.login = 'DROPBOX_APP_KEY';
  http.password = 'DROPBOX_APP_SECRET';

  // Get the refresh token from the JSON we saved when originally getting the access token.
  // (See Get Dropbox OAuth2 Access Token w/ Refresh Token
  final json = CkJsonObject();
  try {
    json.loadFile('qa_data/tokens/dropbox.json');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final req = CkHttpRequest();
  req.addParam('grant_type', 'refresh_token');
  req.addParam('refresh_token', json.stringOf('refresh_token'));

  req.httpVerb = 'POST';
  req.contentType = 'application/x-www-form-urlencoded';

  final resp = CkHttpResponse();
  try {
    http.httpReq('https://api.dropbox.com/oauth2/token', req, resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final sbResponseBody = CkStringBuilder();
  resp.getBodySb(sbResponseBody);

  final jResp = CkJsonObject();
  jResp.loadSb(sbResponseBody);
  jResp.emitCompact = false;

  print('Response Body:');
  print(jResp.emit());

  final respStatusCode = resp.statusCode;
  print('Response Status Code = $respStatusCode');
  if (respStatusCode >= 400) {
    print('Response Header:');
    print(resp.header);
    print('Failed.');
    return;
  }

  // Sample JSON response:
  // (Sample code for parsing the JSON response is shown below)

  // {
  //   "access_token": "sl.AC75WPYRqOi0mxcRqlimbV9FKHu04biz5qHwatG3MTgzFK7kLrGVlM9EgP4603tE7bWw0s1rMbTKiHsf37TUshPYvq-3r0qeBr_PrZIAibN8XOQicvboiOnqx6JrDekq-w8D-tE",
  //   "token_type": "bearer",
  //   "expires_in": 14400
  // }

  final accessToken = jResp.stringOf('access_token');
  print('New Access Token: $accessToken');

  // Perhaps update our Dropbox JSON file with the new access token.
  // (The existing refresh token does not change, and can be used over and over to mint new access tokens.)
  json.updateString('access_token', accessToken);

  json.writeFile('qa_data/tokens/dropbox.json');
}