Implementing facebook-OmniAuth using Rails

Question

i have searching all these days to implement OmniAuth using facebook by the use of devise. I have visited so many sites including the git wiki https://github.com/plataformatec/devise/wiki/OmniAuth%3A-Overview. But i did not get the answer i was looking for. Also i have downloaded a book for devise for the same,but same in book too. i have briefly explain what all things i have did for implementing the omniauth. steps

download and install devise gem from https://github.com/plataformatec/devise#getting-started

2.make the devise ready using overriding the Registrations controller and views

3.I have already visited the rails casts http://railscasts.com/episodes/360-facebook-authentication?view=asciicast but not explanatory

i need a step by step explanation of how to implement OmniAuth-facebook in rails .

I have used rails 4 with ruby 2.2.1 .

Is better you explain us, what's your problem, or what you tried by code — soltex
i would like to get a step by step explanation for that, can you do it? — Anoob K Bava
This may be useful for you: (Part1) youtube.com/watch?v=11BInedaQSo, (Part2) youtube.com/watch?v=1yRvsI34Ysw. It worked for me. — soltex

webster webster · Accepted Answer · 2015-09-22T11:44:34

Add gem 'omniauth' to your Gemnfile
Add 2 more columns i.e 'uid' and 'provider' to our user model
Add gem 'omniauth-facebook' to your Gemfile
Create an application in Facebook to get the secret key. Next, you need to declare the provider in your (config/initializers/devise.rb) and require it:

require "omniauth-facebook"

config.omniauth :facebook, "APP_ID", "APP_SECRET"
make your model (e.g. app/models/user.rb) omniauthable:

devise :omniauthable
Restart the server
Now Devise will create the following url methods.

user_omniauth_authorize_path(provider)

user_omniauth_callback_path(provide)
Use the below line of code in your view file wherever you want to provide the Facebook link to authorize for the users:

<%= link_to "Sign in with Facebook", user_omniauth_authorize_path(:facebook) %>

When the user clicks on the above link, they will redirects to the Facebook login page, after entering their credentials it will again redirect the user back to our applications Callback method
When the user clicks on the above link, they will redirects to the Facebook login page, after entering their credentials it will again redirect the user back to our applications Callback method:

devise_for :users, :controllers => { :omniauth_callbacks => "users/omniauth_callbacks" }

Now we we are going to add a new controller file inside our Rails controller directory "app/controllers/users/omniauth_callbacks_controller.rb" and put the following line code in your omniauth_callbacks_controller.rb file.

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.find_for_facebook_oauth(request.env["omniauth.auth"], current_user) 
    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

Now we are going to implement the find_for_facebook_oauth method in our user model (e.g. app/models/user.rb) :

def self.find_for_facebook_oauth(auth, signed_in_resource=nil)
  user = User.where(:provider => auth.provider, :uid => auth.uid).first
  if user
    return user
  else
    registered_user = User.where(:email => auth.info.email).first
    if registered_user
      return registered_user
    else
      user = User.create(name:auth.extra.raw_info.name,
                                    provider:auth.provider,
                                    uid:auth.uid,
                                    email:auth.info.email,
                                    password:Devise.friendly_token[0,20]
                                  )
    end
  end
end

Implementing facebook-OmniAuth using Rails

2 Answers