Google+ Sign Up with Devise and Rails (google_oauth2) - ruby-on-rails

Question

I'm getting the following error when trying to sign in through google+ using the google_oauth2 gem.
undefined method `find_for_google_oauth2' for #<Class:0x007ff70a337148>
Here's the three files I've altered for sign up.
user.rb
def google_oauth2
user = User.from_omniauth(request.env["omniauth.auth"])
if user.persisted?
flash.notice = "Signed in Through Google!"
sign_in_and_redirect user
else
session["devise.user_attributes"] = user.attributes
flash.notice = "You are almost Done! Please provide a password to finish setting up your account"
redirect_to new_user_registration_url
end
end
omniauth_callbacks_controller.rb
def google_oauth2
# You need to implement the method below in your model (e.g. app/models/user.rb)
#user = User.find_for_google_oauth2(request.env["omniauth.auth"], current_user)
if #user.persisted?
flash[:notice] = I18n.t "devise.omniauth_callbacks.success", :kind => "Google"
sign_in_and_redirect #user, :event => :authentication
else
session["devise.google_data"] = request.env["omniauth.auth"]
redirect_to new_user_registration_url
end
end
and I've added config.omniauth :google_oauth2 in my devise.rb file.
routes.rb
devise_for :users, :controllers => { :registrations => "registrations", :sessions => "sessions", :omniauth_callbacks => "users/omniauth_callbacks" }

Answer 1

You are calling find_for_google_oauth2 from the omniauth_callbacks_controller, but you are using the wrong method name google_oauth2. You should replace google_oauth2 with find_for_google_oauth2.
And it seems like the code in user.rb is incorrect because it contains the controller code. Do you see it looks exactly the same like your controller code? :)
Correct code for user.rb
def self.find_for_google_oauth2(access_token, signed_in_resource=nil)
data = access_token.info
user = User.where(:email => data["email"]).first
# Uncomment the section below if you want users to be created if they don't exist
# unless user
# user = User.create(name: data["name"],
# email: data["email"],
# password: Devise.friendly_token[0,20]
# )
# end
user
end
Read more here: https://github.com/zquestz/omniauth-google-oauth2#devise