User.rb

user.rb

class User < ActiveRecord::Base
  devise :trackable, :validatable, :database_authenticatable, :rememberable,
         :omniauthable, :omniauth_providers => [:google_oauth2]

  attr_accessible :email, :password, :password_confirmation, :remember_me, :name, :provider, :uid

  def self.find_by_authentication_token(access_token)
    client = OAuth2::Client.new(ENV['GOOGLE_OAUTH2_ID'],ENV['GOOGLE_OAUTH2_SECRET'])
    begin
      response = client.request(:get, 'https://www.googleapis.com/oauth2/v2/tokeninfo', :params => {
          :access_token => access_token
        }).parsed
      
      return User.where(:email => response['email']).first
    rescue
      # Oauth2::Client throws an Exception when access_token is not valid anymore
      return nil
    end
  end

  has_many :openings
end