Introduction
As my coding partner and I are working on our final Rails project, I thought it was a great time to share how we integrated
‘omniauth-facebook’ ‘omniauth-facebook’What is devise and omniauth-facebook
Devise is a ruby on rails gem which handles all user authentication features in your rails application in a very flexible manner.
Omniauth-facebook on the other hand enables user authentication (login/signup) using their existing facebook account.
In general the Omniauth-provider is a service which enables user authentication through 3rd-party services such as facebook, twitter, google, and so on.
Setting up devise and omniauth-facebook
Build a basic rails application
#create rails project
rails new my-rails-app — database=postgresql
#navigate to project directory
cd my-rails-app
#create database
run rails db:create
run rails db:migrateDevise gem installation and setup
#generate the pages controller to handle the app home page
rails g controller Pages home
#open config/routes.rb
-set root route
root to: ‘pages#home’
#add devise gem to gemfile#my-rails-app/Gemfile
gem ‘devise’
run bundle install
rails g devise:install
#set alerts and notices in application.html.erb
run rails g devise:views
run rails g devise User
run rails db:migrateOmniauth-facebook setup
1. Go to https://developers.facebook.com/ and create facebook developer account
2. add ‘omniauth-facebook’ gem to your gemfile
#my-rails-app/Gemfile
gem ‘omniauth-facebook’3. Update the User Table with the params needed
run rails g migration AddOmniauthToUsers provider:string uid:string name:string image:text
run rails db:migrate4. Update initializer
# config/initializers/devise.rb
config.omniauth :facebook, “App ID”, “App Secret”,
callback_url: “http://localhost:3000/auth/facebook/callback"5. Update the model
# app/models/user.rb
devise :omniauthable, :omniauth_providers => [:facebook]
verify your schema for the additional fields/columns
vi-Add a Link to Facebook
app/views/pages/home.html.erb
<% unless current_user %>
<%= link_to “Sign in with Facebook”, user_facebook_omniauth_authorize_path %>
<% else %>
<%= link_to “Logout”, destroy_user_session_path, method: :delete %>
<% end %>vii-Update Routes
# config/routes.rb
devise_for :users, :controllers => { :omniauth_callbacks => “users/omniauth_callbacks” }6. Create a users directory
mkdir app/controllers/users7. Create a users controller with the following omniauth methods
# app/controller/users/omniauth_callbacks_controller.rb
class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
def facebook
@user = User.from_omniauth(request.env[“omniauth.auth”])
if @user.persisted?
sign_in_and_redirect @user, :event => :authentication
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
def failure
redirect_to root_path
end
end8. Add custom methods to the User model
# app/models/user.rb
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
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
endREFERENCES