module ActionController::Caching::Pages::ClassMethods

def cache_page(content, path, extension = nil)

cache_page "I'm the cached content", "/lists/show"
Manually cache the +content+ in the key determined by +path+. Example: 
def cache_page(content, path, extension = nil)
  return unless perform_caching
  path = page_cache_path(path, extension)
  instrument_page_cache :write_page, path do
    FileUtils.makedirs(File.dirname(path))
    File.open(path, "wb+") { |f| f.write(content) }
  end
end

def caches_page(*actions)

caches_page :index, :if => Proc.new { |c| !c.request.format.json? }
# cache the index action except for JSON requests

caches_page :index
# cache the index action

Usage:

matches the triggering url.
Caches the +actions+ using the page-caching approach that'll store the cache in a path within the page_cache_directory that 
def caches_page(*actions)
  return unless perform_caching
  options = actions.extract_options!
  after_filter({:only => actions}.merge(options)) { |c| c.cache_page }
end

def expire_page(path)

expire_page "/lists/show"
Expires the page that was cached with the +path+ as a key. Example: 
def expire_page(path)
  return unless perform_caching
  path = page_cache_path(path)
  instrument_page_cache :expire_page, path do
    File.delete(path) if File.exist?(path)
  end
end

def instrument_page_cache(name, path) 

def instrument_page_cache(name, path)
  ActiveSupport::Notifications.instrument("#{name}.action_controller", :path => path){ yield }
end

def page_cache_file(path, extension) 

def page_cache_file(path, extension)
  name = (path.empty? || path == "/") ? "/index" : URI.unescape(path.chomp('/'))
  unless (name.split('/').last || name).include? '.'
    name << (extension || self.page_cache_extension)
  end
  return name
end

def page_cache_path(path, extension = nil) 

def page_cache_path(path, extension = nil)
  page_cache_directory + page_cache_file(path, extension)
end