We didn’t have much to discuss in our standup this morning - most of us had finished the first part of the week’s challenge and we had been going through the second part.

My pair partner and I spent the morning, working out how to allow users to log in to our website, using a 3rd party login such as Facebook, Twitter and Github. We have added a gem called omniauth-facebook to our Gemfile which allowed us to add Facebook as a provider.

I will quickly go through how we have added Facebook to our website. The material is taken from here.

  • After running bundle, we have added the columns ‘provider’ (value string) and ‘uid’ (value string) to our User model, by running in our command line (in the project’s directory) bin/rails g migration AddOmniauthToUsers provider:index uid:index and bin/rake db:migrate

  • Next, we have declared the provider in our config/initializers/devise.rb: config.omniauth :facebook, "APP_ID", "APP_SECRET" and replaced APP_ID and APP_SECRET with our app id and secret. Note, to get our “APP_ID” and “APP_SECRET”, we have created a Facebook Developer application, making note of the two keys we have been given. We have also added extra fields to our code as Facebook have changed to api v2.4 since 8 July 2015: config.omniauth :facebook, "APP_ID", "APP_SECRET", scope: 'email', info_fields: 'email'

  • The next thing we did is to implement a callback and in our config/routes.rb file and tell Devise in which controller we would implement Omniauth callbacks: devise_for :users, :controllers => { :omniauth_callbacks => "users/omniauth_callbacks" }

  • We have now created new folder and file in our controller as follow “app/controllers/users/omniauth_callbacks_controller.rb” and added the following code:

    class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
  def facebook
    # You need to implement the method below in your model (e.g. app/models/user.rb)
    @user = User.from_omniauth(request.env["omniauth.auth"])

    if @user.persisted?
      sign_in_and_redirect @user, :event => :authentication #this will throw if @user is not activated
      set_flash_message(:notice, :success, :kind => "Facebook") if is_navigational_format?
    else
      session["devise.facebook_data"] = request.env["omniauth.auth"]
      redirect_to new_user_registration_url
    end
  end
end

  • As we could see from the code above, we would need to create the method from_oniauth in our user model (i.e. app/models/user.rb ):

    def self.from_omniauth(auth)
  where(provider: auth.provider, uid: auth.uid).first_or_create do |user|
    user.email = auth.info.email
    user.password = Devise.friendly_token[0,20]
    user.name = auth.info.name   # assuming the user model has a name
    user.image = auth.info.image # assuming the user model has an image
  end
end

  • Last but not least, we have captured a copy of the Facebook email (once the authorisation from the method above is completed) by adding:

    class User < ActiveRecord::Base
  def self.new_with_session(params, session)
    super.tap do |user|
      if data = session["devise.facebook_data"] && session["devise.facebook_data"]["extra"]["raw_info"]
        user.email = data["email"] if user.email.blank?
      end
    end
  end
end

One thing to note is that we are using a gem called devise which has created the user login, logout, signing up etc. That’s why we haven’t added sign-in and sign-out links to Facebook as Devise have done this for us. Nice, right?

I also played some bridge tonight with a friend which was fun!

Good night.

Zhivko