widget_sweep.rb

class WidgetSweeper < ActionController::Caching::Sweeper
  observe Widget
  def after_update(widget)
    expire_cache_for(widget)
  end

  def after_destroy(widget)
    expire_cache_for(widget)
  end

  def after_create(widget)
    expire_cache_for(widget)
  end

private
  def expire_cache_for(widget)
    expire_action(:controller=>"widgets",:action=>"show",:id=>widget.id)
    expire_action(:controller=>"widgets",:action=>"index")
  end
end