Facebook omniauth rails

application.html.erb

# app/views/layout/application.html.rb

<div class="provider">
	<% unless current_user.link_provider?('facebook') %>
		<%= link_to "Link your facebook profile", "/auth/facebook" %>
	<% else %>
		<%= link_to "Delete facebook profile linking", "/delete/facebook/profile" %>
	<% end %>
</div>

develoment.rb

# config/environments/develoment.rb

ENV['FACEBOOK_APP_ID'] = "XXXXXXXXXXXXX"
ENV['FACEBOOK_SECRET'] = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'

Gemfile

# Gemfile

gem 'omniauth'
gem 'omniauth-facebook'

identiies_controller.rb

# app/controllers/identiies_controller.rb

# encoding: utf-8
class IdentitiesController < ApplicationController

	def create
		current_user.find_for_oauth(env["omniauth.auth"])
		redirect_to("/#{current_user.role}/home", :flash => {:success => "Merci #{current_user.facebook.name}, votre profile facebook est correctement lié à notre plateforme"})
	end

	def destroy
		if current_user.identity_destroy(params[:provider])
			redirect_to("/#{current_user.role}/home", :flash => {:success => "Votre profile #{params[:provider]} a bien été dissocié de notre plateforme"})
		else
			redirect_to("/#{current_user.role}/home", :flash => {:error => "Sorry there was an error"})
		end
	end

end

identity.rb

# app/models/identity.rb

class Identity < ActiveRecord::Base
  attr_accessible :provider, :uid, :name, :oauth_token, :oauth_expires_at, :user_id
  belongs_to :user
  validates_presence_of :uid, :provider

  def self.find_for_oauth(auth, user_id)
    identity = Identity.where(:provider => auth.provider, :uid => auth.uid).first
    identity = Identity.create(:provider => auth.provider, :uid => auth.uid, :name => auth.info.name, :oauth_token => auth.credentials.token, :oauth_expires_at => Time.at(auth.credentials.expires_at), :user_id => user_id) if identity.nil?
    identity
  end
end

omniauth.rb

# config/initializers/omniauth.rb

OmniAuth.config.logger = Rails.logger

Rails.application.config.middleware.use OmniAuth::Builder do
  provider :facebook, ENV['FACEBOOK_APP_ID'], ENV['FACEBOOK_SECRET'], {:scope => "public_profile, user_friends, email, user_about_me, user_activities, user_birthday, user_events, user_interests, user_likes, user_location, user_status, user_tagged_places, user_website, read_friendlists, read_insights, read_stream, manage_notifications"}
end

routes.rb

  # config/routes.rb
  
  ########################### 
  # Provider connect routes #
  ###########################
  
  match 'auth/:provider/callback', to: 'identities#create'
  match 'auth/failure', to: redirect('/')
  match 'delete/:provider/profile', to: 'identities#destroy'

user.rb

# app/models/user.rb

def find_for_oauth(auth)
    identity = Identity.find_for_oauth(auth, self.id)
end

def link_provider?(provider)
    Identity.where(:provider => provider, :user_id => self.id).present?
end

def identity_destroy(provider)
  identity = self.identities.where(:provider => provider).first
  if identity.present?
    identity.delete
    true
  else
    false
  end
end

def facebook
  self.identities.where(:provider => 'facebook').first
end