Integrating with LinkedIn using Rails, Mongoid, Devise, Omniauth, LinkedIn Gem

devise.rb

# config/initializers/devise.rb

# ==> OmniAuth
# Add a new OmniAuth provider. Check the wiki for more information on setting
# up on your models and hooks.
# config.omniauth :github, 'APP_ID', 'APP_SECRET', :scope => 'user,public_repo'
require "omniauth-linkedin"
config.omniauth :linkedin, "your-app-id", "your-app-secret", :scope => 'r_basicprofile r_emailaddress rw_nus'

Gemfile

# Gemfile

gem "linkedin"
gem "omniauth"
gem "omniauth-linkedin"

gistfile1.rb

LinkedinFactory.add_share(user, something_to_share)

linkedin_connection.rb

# app/models/user/linkedin_connection.rb

class User::LinkedinConnection
  include Mongoid::Document
  include Mongoid::Timestamps

  embedded_in :user

  field :token
  field :secret
end

linkedin_factory.rb

# lib/linkedin_factory.rb

class LinkedinFactory

  def self.authorize_user(user)
    token = user.user_linkedin_connection.token
    secret = user.user_linkedin_connection.secret

    client = LinkedIn::Client.new(LinkedIn.token, LinkedIn.secret)
    client.authorize_from_access(token, secret)
    client
  end

  def self.add_share(user, update)
    client = self.authorize_user(user)
    client.add_share(update)
  end

end

omniauth.rb

# config/initializers/omniauth.rb

OmniAuth.config.logger = Rails.logger

omniauth_callbacks_controller.rb

# app/controllers/omniauth_callbacks_controller.rb

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController

  def linkedin
    if current_user
      connect_to_linkedin
    else
      sign_in_via_linkedin
    end
  end
  
private

  def connect_to_linkedin
    if current_user.connect_to_linkedin(request.env["omniauth.auth"])
      set_flash_message(:notice, :success, :kind => "LinkedIn")
    else
      set_flash_message(:notice, :failure, :kind => "LinkedIn")
    end
    redirect_to root_url
  end

  def sign_in_via_linkedin
    @user = User.find_for_linkedin_oauth(request.env["omniauth.auth"])

    if @user
      @user.connect_to_linkedin(request.env["omniauth.auth"])
      sign_in_and_redirect @user, :event => :authentication
      set_flash_message(:notice, :success, :kind => "LinkedIn") if is_navigational_format?
    else
      flash[:notice] = "Couldn't find a user connected to your LinkedIn account.  Please sign in and then connect your account to LinkedIn."
      redirect_to new_user_session_url
    end
  end
end

routes.rb

# config/routes.rb

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

user.rb

# app/models/user.rb

devise :omniauthable

## Omniauthable
field :provider
field :uid

embeds_one :user_linkedin_connection, :class_name => 'User::LinkedinConnection'

def connect_to_linkedin(auth)
  self.provider = auth.provider
  self.uid = auth.uid
  self.user_linkedin_connection = User::LinkedinConnection.new(:token => auth["extra"]["access_token"].token, :secret => auth["extra"]["access_token"].secret)
  unless self.save
    return false
  end
  true
end

def disconnect_from_linkedin!
  self.provider = nil
  self.uid = nil
  self.user_linkedin_connection = nil
  self.save!
end

view.html.haml

= link_to "Connect to LinkedIn", user_omniauth_authorize_path(:linkedin)

= link_to "Sign in with LinkedIn", user_omniauth_authorize_path(:linkedin)