gistfile1.rb

class Foo < Apotomo::Widget
  cache :display, :my_cache_key
  
  def my_cache_key
    { :site_id => current_site.id,
      :article_id => @opts[:id] 
    }
  end
end

class Bar < Apotomo::Widget
  cache :display, :my_cache_key
  
  def my_cache_key
    { :project_id => current_project.id,
      :user_id    => current_user.id,
      :size       => @opts[:size],
    }
  end
end


class MySweeper < ActionController::Caching::Sweeper
  observe FooModel, BarModel

  def after_update(record)
    widget = case
      when record.is_a?(FooModel) then :foo
      when record.is_a?(BarModel) then :bar
    end

    key = send(:"#{widget}_cache_key", record)

    expire_cell_state widget, :display, key
  end

  def foo_cache_key(record)
    { :site_id => current_site.id,
      :article_id => record.id 
    }
  end

  def bar_cache_key(record)
    { :project_id => record.project.id,
      :user_id    => current_user.id,
      :size       => "wtf, the sweeper knows nothing about this"
    }
  end
end