Would "Devise" still be useful if I'm using "sign on with google"?
that is, given in my Rails app I'll build it using OmniAuth (maybe oauth plugin) to (a) authenticate/signin using google, and (b) use OAuth to access google data via the google api's at times in the app, would their be any benefit using "Devise" to create the user model?
Or is 90% of Devise no use to a rails app for which authentication takes place via a "sign in via google" type approach?
CLARIFICATION: - The assumption for the question is that I would never need to do/want to do authentication through email/username and password in the future. i.e. will be only ever "signin via google", hence I trying to understand beyond authentication whether Devise still be useful?
Devise is pointless if you are purely using external authentication providers. Omniauth will provide you with all you need for Google, Facebook, Twitter etc authentication.