contacts_controller.rb

class Admin::PhotosController < Admin::TablesController  
  cache_sweeper :photo_sweeper, :only => [:create, :update, :destroy]

# standard methods for  index, show, new, edit, update, destroy

end

initilizer.rb

                
FLEXI_METHODS = [
                 {:method => :large_thumb_access_cover, :width => 150, :height => 150 },
                 {:method => :table_show, :width => 75, :height => 75},
                 {:method => :sort_photo, :width => 50, :height => 50},
                 {:method => :builder_show, :width => 125, :height => 125},
                 {:method => :builder_thumb, :width => 25, :height => 25},
                 {:method => :resource_photo, :width => 125, :height => 125},
                 {:method => :record_show, :width => 500, :height => 500},
                 {:method => :record_show_thumb, :width => 30, :height => 30},
                 {:method => :show },
                ]         

photo_sweeper.rb

class PhotoSweeper < ActionController::Caching::Sweeper
  observe Photo

  def after_save(photo)
    expire_action_cache(photo)
  end

  def after_destroy(photo)
    expire_action_cache(photo)
  end

  private

    def expire_action_cache(photo)
      FLEXI_METHODS.each do |flexi|
        # Expired fragment should look like: views/localhost:3000/photos/44/large_thumb_access_cover.jpg

        expire_fragment(:controller => :photos, :action => photo.id, :id => "#{flexi[:method]}.#{photo.get_format}") 
      end
    end

end

photos_controller.rb

class Assets::PhotosController < ApplicationController

 FLEXI_METHODS.each {|flexi| caches_action flexi[:method] }
  
  FLEXI_METHODS.each do |flexi|
    define_method flexi[:method] do
      @photo = Photo.find(params[:id])
      if flexi[:width] && flexi[:height]
        @width = flexi[:width]
        @height = flexi[:height]
        render :template => "assets/photos/flexi/resize"
      else
        render :template => "assets/photos/flexi/#{flexi[:method]}"
      end
    end
  end

resize.flexi

@photo.operate do |photo|
  photo.resize("#{@width}x#{@height}", :crop => true, :upsample => false, :stretch => false)
end