books_controller.rb

class BooksController < ApplicationController
  before_action :load_book
  before_action :check_access
  def show
    @comments = @book.comments.reversed_nested_set.with_state([:draft, :published])
  end

  def subscribed
  end
private
  def load_book
    @book = Book.find_by_slug(params[:id]) or raise "No such book '#{params[:id]}'"
  end


  def check_access
    if !@book.published? && !(current_user && current_user.admin?)
     flash[:warning] = "Please login as admin to view this page"
     redirect_to root_path
  end
end