class BookController < ApplicationController

USER_ID, PASSWORD = "zara", "pass123"
 
# Require authentication only for edit and delete operation
   before_filter :authenticate, :only => [ :edit, :delete ]
  
def list
   @books = Book.find(:all)
end
   
def show
   @book = Book.find(params[:id])
end
   
def new
   @book = Book.new
   @subjects = Subject.find(:all)
end
   
def create
   @book = Book.new(params[:book])
   if @book.save
      redirect_to :action => 'list'
   else
      @subjects = Subject.find(:all)
      render :action => 'new'
   end
end
   
def edit
   @book = Book.find(params[:id])
   @subjects = Subject.find(:all)
end
   
def update
   @book = Book.find(params[:id])
   if @book.update_attributes(params[:book])
      redirect_to :action => 'show', :id => @book
   else
      @subjects = Subject.find(:all)
      render :action => 'edit'
   end
end
   
def delete
   Book.find(params[:id]).destroy
   redirect_to :action => 'list'
end
   
def show_subjects
   @subject = Subject.find(params[:id])
end
   
private
   def authenticate
      authenticate_or_request_with_http_basic do |id, password| 
         id == USER_ID && password == PASSWORD
      end
   end
end