title: How to use Google Oauth2 for both signing in users and creating new user accounts in a rails app?
body: <p>I'm working on google authentication for a rails app. Currently using the <a href="https://github.com/zquestz/omniauth-google-oauth2" rel="nofollow noreferrer">omniauth-google-oauth2</a> gem to implement Google auth. I've managed to have users sign in using google. However, I'd also like users to be able to sign up using google. My problem is that I've matched the google callback URL to a particular controller action (sessions#create).
  Is it possible to choose between 2 redirect URIs based on whether users are signing in or signing up? Currently, my only idea is to create new google client credentials to be used for sign up, I hope there is a better way.</p>