NoMethodError in SessionsController#create - Undefined method '[]' for #<Oauth::Access_Token...> - ruby-on-rails

Question

I'm having some trouble storing a user's Twitter access token in the User model. I have installed the Omniauth gem as per Railscast #241 and was successful in setting up the Twitter authentication, storing the "uid" and "name". In order to make authenticated Twitter API calls, I wanted to store the user's access token and access token secret and thus created a migration to create those fields. I did that successfully and can assign those fields successfully in the Rails Console to records that do not have the stored. When trying to authenticate a new user, however, and pull this information in from the start, I get the error listed in the title. HEre is additional error information:
app/models/user.rb:13:in `block in create_from_omniauth'
app/models/user.rb:10:in `create_from_omniauth'
app/models/user.rb:6:in `from_omniauth'
app/controllers/sessions_controller.rb:5:in `create'
I follow down this path from the sessions controller to the User model but can't figure out what is causing the error. I have included those documents below.
Sessions Controller
class SessionsController < ApplicationController
def create
user = User.from_omniauth(env["omniauth.auth"])
session[:user_id] = user.id
redirect_to root_url, notice: "Signed in"
end
def destroy
session[:user_id] = nil
redirect_to root_url, notice: "Signed out"
end
end
User Model
class User < ActiveRecord::Base
attr_accessible :name, :uid, :access_token, :access_token_secret
has_many :events
def self.from_omniauth(auth)
where(auth.slice('uid')).first || create_from_omniauth(auth)
end
def self.create_from_omniauth(auth)
create! do |user|
user.uid = auth["uid"]
user.name = auth["info"]["nickname"]
user.access_token = auth["extra"]["access_token"]["token"]
user.access_token_secret = auth["extra"]["access_token"]["secret"]
end
end
end
Can anyone help me troubleshoot this error? I know it has to do with setting the access_token fields in the create_from_omniauth method as it works fine without them. I've been banging my head trying to figure out why these won't work. Thanks in advance for any help.

Answer 1

I doubt why you need to save these tokens as they looks of no use. In this case, the most important thing is the Twitter returned uid for identifying or create user.
Anyway, the reason of your error is there are not such keys.
auth['extra']['access_token'] is a string, there is no further sub keys.
:extra => {
:access_token => "", # An OAuth::AccessToken object
To access token and secret, you can use auth['credentials']
:credentials => {
:token => "a1b2c3d4...", # The OAuth 2.0 access token
:secret => "abcdef1234"
},
Reference:
https://github.com/arunagw/omniauth-twitter#authentication-hash
https://github.com/intridea/omniauth/wiki/Auth-Hash-Schema#schema-10-and-later