title: How do I check to see if specific attribute changed upon rails update method?
body: <p>When I update a record, I want the program to then see if a certain attribute was updated during that update save.</p>
  <p>Specifically, after updating the record with the params, I want the program to see if the <code>@state_race.poll</code> parameter changed. If it did, I want to execute another code block.</p>
  <p>How do I check to see if certain attribute changed?</p>
  <p>My <code>@state_race.poll_changed?</code> isn't working.</p>
  <pre><code>  def update
      @state_race = StateRace.find(params[:id])
      if @state_race.update_attributes(state_race_params)
      puts 'race updated' 
          if  @state_race.poll_changed?
            puts 'poll changed' 
          else 
          end
      else
        render('edit')
      end 
    end
  </code></pre>