Devise-Omniauth-Multiple-Providers

In this tutorial we will use four Social Services 'Linkedin, Twitter, Google+, Facebook', but the code will allow you to add extra social service as per the requirement of your product.

Step 1: Add and Install Devise Gem

Modify your Gemfile to include the Devise gem

gem 'devise'

Then update your gems with

bundle install

Install the devise gem with the generator provided

rails generate devise:install

Then create your Devise model (e.g. User) using generator

rails generate devise User

Devise by default generates some migrations, so you'll need to run the created migrations

rake db:migrate

Now restart your server to get the changes

Step 2: Add migrations to create authentication_provider and user_authentication

authentication_provider Migration

class CreateAuthenticationProviders < ActiveRecord::Migration
    def change
        create_table "authentication_providers", :force => true do |t|
            t.string   "name"
            t.datetime "created_at",                 :null => false
            t.datetime "updated_at",                 :null => false
        end
        add_index "authentication_providers", ["name"], :name => "index_name_on_authentication_providers"
        AuthenticationProvider.create(name: 'facebook')
        AuthenticationProvider.create(name: 'twitter')
        AuthenticationProvider.create(name: 'gplus')
        AuthenticationProvider.create(name: 'linkedin')
    end
  end

user_authentication.rb Migration

class CreateUserAuthentications < ActiveRecord::Migration
    def change
        create_table "user_authentications", :force => true do |t|
            t.integer  "user_id"
            t.integer  "authentication_provider_id"
            t.string   "uid"
            t.string   "token"
            t.datetime "token_expires_at"
            t.text     "params"
            t.datetime "created_at",                 :null => false
            t.datetime "updated_at",                 :null => false
        end
        add_index "user_authentications", ["authentication_provider_id"], :name => "index_user_authentications_on_authentication_provider_id"
        add_index "user_authentications", ["user_id"], :name => "index_user_authentications_on_user_id"
    end
  end

Run the migrations with following command

rake db:migrate

Step 3: Add Associations in authentication_provider and user_authentication

authentication_provider.rb

has_many :users
has_many :user_authentications

user_authentication.rb

  belongs_to :user
  belongs_to :authentication_provider
  
  serialize :params

  def self.create_from_omniauth(params, user, provider)
      token_expires_at = params['credentials']['expires_at'] ? Time.at(params['credentials']['expires_at']).to_datetime : nil
      create(
              user: user,
              authentication_provider: provider,
              uid: params['uid'],
              token: params['credentials']['token'],
              token_expires_at: token_expires_at,
              params: params,
            )
  end

Step 4: Create Controller users/omniauth_callbacks_controller.rb

  class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
    include OmniConcern
    %w[facebook twitter gplus linkedin].each do |meth|
      define_method(meth) do
        create
      end
    end
  end

Add route for users/omniauth_callbacks_controller.rb in routes.rb

  devise_for :users, controllers: {omniauth_callbacks: 'users/omniauth_callbacks'}

Step 5: Create Controller Concern omni_concern.rb

  module OmniConcern
    extend ActiveSupport::Concern
      def create
        auth_params = request.env["omniauth.auth"]
        provider = AuthenticationProvider.get_provider_name(auth_params.try(:provider)).first
        authentication = provider.user_authentications.where(uid: auth_params.uid).first
        existing_user = User.where('email = ?', auth_params['info']['email']).try(:first)
        if user_signed_in?
          SocialAccount.get_provider_account(current_user.id,provider.id).first_or_create(user_id: current_user.id ,  authentication_provider_id: provider.id , token: auth_params.try(:[],"credentials").try(:[],"token") , secret: auth_params.try(:[],"credentials").try(:[],"secret"))
          redirect_to new_user_registration_url
        elsif authentication
          create_authentication_and_sign_in(auth_params, existing_user, provider)
        else
          create_user_and_authentication_and_sign_in(auth_params, provider)
        end
      end
      def sign_in_with_existing_authentication(authentication)
        sign_in_and_redirect(:user, authentication.user)
      end
      def create_authentication_and_sign_in(auth_params, user, provider)
        UserAuthentication.create_from_omniauth(auth_params, user, provider)
        sign_in_and_redirect(:user, user) 
      end
      def create_user_and_authentication_and_sign_in(auth_params, provider)
        user = User.create_from_omniauth(auth_params)
        if user.valid?
            create_authentication_and_sign_in(auth_params, user, provider)
        else
            flash[:error] = user.errors.full_messages.first
            redirect_to new_user_registration_url
      end
   end
  end

Step 6: Add following code to user.rb

  include OmniauthAttributesConcern
    
  has_many :user_authentications

  devise :omniauthable, :database_authenticatable, :registerable,:recoverable, :rememberable, :trackable

  def self.create_from_omniauth(params)
      self.send(params.provider,params)
  end

Step 7: Add Model Concern omniauth_attributes_concern.rb

  module OmniauthAttributesConcern
      extend ActiveSupport::Concern
      module ClassMethods
          Add Methods here 
      end
  end

In this concern we can create Methods for each social media to fetch and store attributes

  def twitter params
      (params['info']['email'] = "dummy#{SecureRandom.hex(10)}@dummy.com") if params['info']['email'].blank?
      attributes = {
                      email: params['info']['email'],
                      first_name: params['info']['name'].split(' ').first,
                      last_name: params['info']['name'].split(' ').last,
                      username: params['info']['nickname'],
                      password: Devise.friendly_token
                  }
      create(attributes)
  end

Note Twitter only return email address if the user has confirmed his/her email at twitter otherwise nil value is returned.

• We can add other social media accounts the same way we have added above
• Profile Image from social account can also be fetched and can be passed as

  remote_image_url: params['info']['image']

Note the above example is meant for carrierwave gem and 'image' in remote_image_url is the DB column. You can use any other gem and pass params['info']['image'] to it.

Step 8: Add Social Media Account Keys in devise.rb

For Facebook

  config.omniauth :facebook, facebook_app_id , facebook_secret_key , :display => "popup" , :scope => 'email,publish_actions', info_fields: 'email,name'

For Twitter

  config.omniauth :twitter, twitter_app_id , twitter_secret_key , :display => "popup" , :scope => 'email'

For Linkedin

  config.omniauth :linkedin, linkedin_app_id ,linkedin_secret_key , :display => "popup", :scope => 'r_emailaddress,r_basicprofile'

For Google+

  config.omniauth :gplus , gplus_app_id ,gplus_secret_key , :display => "popup" , scope: 'userinfo.email, userinfo.profile'

Note: display: "popup" attribute is used when we want social media signup to open in a separate browser window

Final Step 9: Add Gems in Gemfile for Omniauth

  gem 'omniauth-oauth2' , '~> 1.3.1'
  gem 'omniauth'
  gem 'omniauth-facebook'
  gem 'omniauth-twitter'
  gem 'omniauth-gplus'
  gem 'omniauth-linkedin'

Run the bundle command, restart the server and Vola!