title: Get data from response after url request in Flutter
body: <p>I'm trying to implement OAuth 1.0 in Flutter.
  OAuth 1.0 works as follows:<a href="https://i.stack.imgur.com/P27Yg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/P27Yg.png" alt="OAuth flow" /></a>
  My app asks for a request token, which is provided by the service I want to authenticate to. Then the user is redirected to a page belonging to the service where it grants the authorization to access data to my app. Now I can ask for the access token which will be used to sign every future data request.</p>
  <p>I'm using <a href="https://github.com/nbspou/dart-oauth1" rel="nofollow noreferrer">this OAuth plugin</a> for the OAuth procedure and <a href="https://pub.dev/packages/url_launcher" rel="nofollow noreferrer">Url Launcher plugin</a> to perform requests, since the first plugin waits for pin data, while I'd like the user to enjoy full automated process.
  I'm able to ask for the request token through the OAuth library, but the following code only launches the url, so I cannot retrieve data from the response.</p>
  <pre><code>if (await canLaunch(url)) {
    await launch(url, forceWebView: true, enableJavaScript: true);
  } else {
    throw 'Could not launch $url';
  }
  </code></pre>
  <p>How can I get data after user interaction?</p>