module ActionController
module Caching
module Fragments
# expire a cache key only if the block returns true or
# if the age of the fragment is more than the specified age argument.
def expire_fragment_by_mtime(key, age=nil, &block)
block = Proc.new { |m| m < age.ago } unless block_given?
if (m = cache_store.mtime(fragment_cache_key(key))) and block.call(m)
expire_fragment(key)
end
end
end
module Actions
module ClassMethods
# adds an option :for
# caches_action :show, :for => 2.hours, :cache_path => ...
# :cache_path is required, unfortunately
def caches_action_with_for(*actions)
original_actions = actions.clone
options = actions.extract_options!
if for_time = options.delete(:for)
cache_path = options[:cache_path]
before_filter do |controller|
cache_path = cache_path.call(controller) if cache_path.respond_to?(:call)
controller.expire_fragment_by_mtime(cache_path, for_time)
end
end
caches_action_without_for(*original_actions)
end
alias_method_chain :caches_action, :for
end
end
end
end
# Add a method to grab the last modified time of the cache key.
# If you use a store other than the FileStore, you'll need to add
# a method like this to your store.
module ActiveSupport
module Cache
class FileStore
def mtime(name)
File.mtime(real_file_path(name)) rescue nil
end
end
end
end
