I actually had this working fine in the past (with the V2 api) but with the V3 API have hit an issue I have the script from the quickstart https://developers.google.com/drive/api/quickstart/js

Works fine, but whenever I go to the page that selects the file it shows the "Authenticate" button again? - even after a refresh.

Is there a way to check if the user had previously clicked authenticate? Basically I need the new equivalent of the old (depreciated) gapi.auth2.getAuthInstance().isSignedIn