authorizationUrl on sidebar of gmail addons using appscript - google-apps-script

Question

I am using Google cloud datastore which is exposed by jersey rest, i have made authentication using oauth2 to access rest APIS.
Now I want to call restful API from my gmail addons to populate some lovs on gmail sidebar.
I have tried oauth2 authentication provided on https://github.com/googlesamples/apps-script-oauth2.
How do i show authorizationUrl on sidebar of gmail using gmail Addons?
CODEBASE
appscript.json
{
"timeZone": "America/Los_Angeles",
"dependencies": {
"enabledAdvancedServices": [{
"userSymbol": "Gmail",
"serviceId": "gmail",
"version": "v1"
}],
"libraries": [{
"userSymbol": "OAuth2",
"libraryId": "1B7FSrk5Zi6L1rSxxTDgDEUsPzlukDsi4KGuTMorsTQHhGBzBkMun4iDF",
"version": "24",
"developmentMode": true
}]
},
"oauthScopes": ["https://www.googleapis.com/auth/gmail.addons.execute", "https://www.googleapis.com/auth/gmail.addons.current.message.metadata", "https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/gmail.readonly", "https://www.googleapis.com/auth/script.external_request", "https://www.googleapis.com/auth/script.storage"],
"gmail": {
"name": "Gmail Add-on Quickstart",
"logoUrl": "https://www.gstatic.com/images/icons/material/system/2x/bookmark_black_24dp.png",
"contextualTriggers": [{
"unconditional": {
},
"onTriggerFunction": "buildAddOn"
}],
"primaryColor": "#4285F4",
"secondaryColor": "#4285F4",
"openLinkUrlPrefixes": ["https://mail.google.com/"],
"version": "TRUSTED_TESTER_V2"
}
}
Code.gs
function buildAddOn(e) {
var driveService = createOauthService();
Logger.log('Access'+driveService.hasAccess()); // GETTING FALSE HERE
Logger.log('Auth URL'+driveService.getAuthorizationUrl()); // GETTING PROPER AUTH URL.
Logger.log('Token'+driveService.getAccessToken()); // NEED TOKEN TO BE USED ON REST CALL
}
function createOauthService() {
return OAuth2.createService('drive')
.setAuthorizationBaseUrl('https://accounts.google.com/o/oauth2/auth')
.setTokenUrl('https://accounts.google.com/o/oauth2/token')
.setClientId('MY CLOUD CONSOLE CLIENT ID')
.setClientSecret('MY SECREAT')
.setCallbackFunction('authCallback')
.setPropertyStore(PropertiesService.getUserProperties())
.setScope('https://www.googleapis.com/auth/drive')
.setParam('login_hint', Session.getActiveUser().getEmail())
.setParam('access_type', 'offline');
.setParam('approval_prompt', 'force');
}
Is this correct way or am i missing something ?
Please suggest.

Answer 1

One documented way to do this is to return a card from your buildAddOn() function which contains a button configured to launch the authorization sequence.
function buildAuthorizeCard() {
var authorizationUrl = getOAuthService().getAuthorizationUrl();
var card = CardService.newCardBuilder();
var section = CardService.newCardSection();
section.addWidget(CardService.newTextButton()
.setText("Authorize MyService")
.setAuthorizationAction(
CardService.newAuthorizationAction()
.setAuthorizationUrl(authorizationUrl)
));
card.addSection(section);
return card.build();
}
You can give that a try.