application_controller.rb

class ApplicationController < ActionController::Base
  before_action :store_location
  protect_from_forgery with: :exception
  
  def store_location
		# store last url as long as it isn't a /users path
		session[:previous_url] = request.referer unless request.fullpath =~ /\/users/
	end
	
	def after_sign_in_path_for(resource)
	  session[:previous_url] || root_path
	end
end