Omniauth Controller Example

sessions_controller.rb

class SessionsController < ApplicationController

	skip_before_filter :verify_authenticity_token, only: :create

	def create
		# Find an identity here
		identity_info 	= Identity.filter_auth_hash(auth_hash)
  		@identity 		= Identity.find_with_omniauth(identity_info)

		if @identity.nil?
			# If no identity was found, create a brand new one here
			@identity 	= Identity.create_with_omniauth(identity_info)
		else
			@identity.update_oauth_token(identity_info)
		end

		if signed_in?
			if @identity.member == current_user
				# User is signed in so they are trying to link an identity with their
				# account. But we found the identity and the user associated with it 
				# is the current user. So the identity is already associated with 
				# this user. So let's display an error message.
				self.current_user = @identity.member
				redirect_to members_path
			else
				# The identity is not associated with the current_user so lets 
				# associate the identity
				@identity.member = current_user
				@identity.save()
				self.current_user = @identity.member
				redirect_to members_path
			end
		else
			if @identity.member.present?
				# The identity we found had a user associated with it so let's 
				# just log them in here
				self.current_user = @identity.member
				redirect_to members_path
			else
				# No user associated with the identity so we need to create a new one
				info 	= Member.filter_auth_hash(auth_hash)
				@member = Member.create_with_omniauth(info)

				if @member
					# Associate the user with the identity
					@identity.member_id = @member.id
					@identity.save
					self.current_user 	= @member

					redirect_to members_path
				else
					redirect_to root_url
				end
			end
		end
	end

	def destroy
		self.current_user = nil
  		redirect_to root_url
	end

	protected

	def auth_hash
		request.env['omniauth.auth']
	end

end