snippet.rb

  #Why can't I have :new there as well?  It works when I got the respond_to in def new, but when using before filter, I get 
  #Called id for nil, which would mistakenly be 4 -- if you really wanted the id of nil, use object_id
  
  before_filter :respond_to_id, :only => [:show, :new, :update]
  def respond_to_id
    respond_to do |format|
      format.html
      format.xml { render :xml => @blogpost }
    end
  end