==About

This is just a subclass of the default FileStore caching option but with a few methods overridden to allow
you to expire the cache. It is extremely basic, but was necessary for my project so I'll release it into the
wild. Keep in mind that this hasn't been heavily tested and there are some quirks. But what do you expect from
a quick-and-dirty hack? :)

More on this: http://blog.ubrio.us/ruby/ruby-rails/simple-rails-time-based-fragment-caching-with-file-store/

==Features

# Can expire from the controller or view
# Super lightweight
# No modification necessary if you are already using FileStore
# Expires caches automatically

==Setup

In your +environment.rb+ file just set the cache_store to :timed_file_store
	config.cache_store = :timed_file_store, File.join(RAILS_ROOT, 'tmp', 'cache')

==Usage

===Expiring Cache From the Controller

Having the controller control the expiration of the cache is good if you are passing along any objects to the 
views since it will not re-run the code if it is already cached. 


	# reports_controller
	# reports/1
	@report = Report.find(params[:id])
	unless fragment_exists?("report_#{@report.id}", :time_to_live => 1.week)
	  @report.run!
	end

	# views/reports/show.html.erb -- or whatever view file
	<% cache("report_#{@report.id}") do -%>;
	  <!-- output the report HTML and such -->
		<%= @report.name %>
	<% end -%>;

===Expiring Cache From the View

If you aren't running any intense code in the controller and just want to keep a certain view fragment 
cached for a while, this should work. (** I didn't test this since I only needed the previous method, but it should work -- maybe with some slight tweaks? :)

	# views/wherever/whatever.html.erb
	<% cache("whatever", :time_to_live => 1.hour) do -%>;
	  <!-- This is my HTML content and all that jazz -->
	  <!-- After 1 hour this cache should be re-freshed -->
	<% end -&>;

Not sure how useful that would be when considering action and page caching... but its possible.