How to invoke a rails sweeper in this scenario? - ruby-on-rails-3

Question

As you can see from code below. I am caching the show action. I also have the following method in the show action View.create_for(#song).
I would like to make it so, when View.create_for(#song) is called, it clears out the respective cache.
How would I go about this? Do I have to manually invoke the rails sweeper in the View model? If so, how?
My controller:
class SongsController < ApplicationController
caches_action :show, :cache_path => (proc do
song_path(params[:id], :user_id => user_signed_in? ? current_user.id : nil)
end)
# I tried with the following line, but this is not what I want. I only want to call the sweeper when `View.create_for(#song)` is called:
# cache_sweeper :views_sweeper, :only => [:show]
def show
#song = Song.find(params[:id])
View.create_for(#song)
end
end
My Sweeper:
class SongsSweeper < ActionController::Caching::Sweeper
observe Song
def after_save(song)
expire_fragment(/songs\/#{song.id}\/.*?/)
end
end

Answer 1

I think you should be referring to the songs_sweeper, not the views_sweeper:
cache_sweeper :songs_sweeper, :only => [:show]
I'm not sure of your requirements, but you could also be more specific in your SongsSweeper by changing after_save to after_create:
class SongsSweeper < ActionController::Caching::Sweeper
observe Song
def after_create(song)
expire_fragment(/songs\/#{song.id}\/.*?/)
end
end