Duel Auth for a script

Duel Auth Example

var localAuth = false;
var sProps = PropertiesService.getScriptProperties();

function doGet() {
  
  var driveService = getDriveService();
  if (!driveService.hasAccess()) {
    return showAuth();
  }
  
  return HtmlService.createHtmlOutput(makeRequest());
}


function getDriveService() {
  return OAuth2.createService('drive')
  .setAuthorizationBaseUrl('https://accounts.google.com/o/oauth2/auth')
  .setTokenUrl('https://accounts.google.com/o/oauth2/token')
  .setClientId(sProps.getProperty("clientId"))
  .setClientSecret(sProps.getProperty("clientSecret"))
  .setProjectKey('...')
  .setCallbackFunction('authCallback')
  .setPropertyStore(sProps)
  .setScope('https://www.googleapis.com/auth/drive')      
  .setParam('access_type', 'offline')
  .setParam('approval_prompt', 'force');
}

function showAuth() {
  var driveService = getDriveService();
  if (!driveService.hasAccess()) {
    var authorizationUrl = driveService.getAuthorizationUrl();
    var template = HtmlService.createTemplate(
      '<a href="<?= authorizationUrl ?>" target="_blank">Authorize</a>. ' +
      'Reopen the sidebar when the authorization is complete.');
    template.authorizationUrl = authorizationUrl;
    var page = template.evaluate();
    return page;
  } else {
    HtmlService.createHtmlOutput("Already have auth");
  }
}

function authCallback(request) {
  var driveService = getDriveService();
  var isAuthorized = driveService.handleCallback(request);
  if (isAuthorized) {
    return HtmlService.createHtmlOutput('Success! You can close this tab.');
  } else {
    return HtmlService.createHtmlOutput('Denied. You can close this tab');
  }
}


function makeRequest() {
  var driveService = getDriveService();
  var response = UrlFetchApp.fetch('https://www.googleapis.com/drive/v2/files?maxResults=10', {
    headers: {
      Authorization: 'Bearer ' + driveService.getAccessToken()
    }
  });
  return response.getContentText(); 
}