require 'set' module ActionController #:nodoc: module Caching # Action caching is similar to page caching by the fact that the entire # output of the response is cached, but unlike page caching, every # request still goes through the Action Pack. The key benefit # of this is that filters are run before the cache is served, which # allows for authentication and other restrictions on whether someone # is allowed to see the cache. Example: # # class ListsController < ApplicationController # before_filter :authenticate, :except => :public # caches_page :public # caches_action :index, :show, :feed # end # # In this example, the public action doesn't require authentication, # so it's possible to use the faster page caching method. But both # the show and feed action are to be shielded behind the authenticate # filter, so we need to implement those as action caches. # # Action caching internally uses the fragment caching and an around # filter to do the job. The fragment cache is named according to both # the current host and the path. So a page that is accessed at # http://david.somewhere.com/lists/show/1 will result in a fragment named # "david.somewhere.com/lists/show/1". This allows the cacher to # differentiate between "david.somewhere.com/lists/" and # "jamis.somewhere.com/lists/" -- which is a helpful way of assisting # the subdomain-as-account-key pattern. # # Different representations of the same resource, e.g. # http://david.somewhere.com/lists and # http://david.somewhere.com/lists.xml # are treated like separate requests and so are cached separately. # Keep in mind when expiring an action cache that # :action => 'lists' is not the same as # :action => 'list', :format => :xml. # # You can set modify the default action cache path by passing a # :cache_path option. This will be passed directly to # ActionCachePath.path_for. This is handy for actions with multiple # possible routes that should be cached differently. If a block is # given, it is called with the current controller instance. # # And you can also use :if (or :unless) to pass a Proc that # specifies when the action should be cached. # # Finally, if you are using memcached, you can also pass :expires_in. # # class ListsController < ApplicationController # before_filter :authenticate, :except => :public # caches_page :public # caches_action :index, :if => proc do |c| # !c.request.format.json? # cache if is not a JSON request # end # # caches_action :show, :cache_path => { :project => 1 }, # :expires_in => 1.hour # # caches_action :feed, :cache_path => proc do |controller| # if controller.params[:user_id] # controller.send(:user_list_url, # controller.params[:user_id], controller.params[:id]) # else # controller.send(:list_url, controller.params[:id]) # end # end # end # # If you pass :layout => false, it will only cache your action # content. It is useful when your layout has dynamic information. # module Actions extend ActiveSupport::Concern module ClassMethods # Declares that +actions+ should be cached. # See ActionController::Caching::Actions for details. def caches_action(*actions) return unless cache_configured? options = actions.extract_options! options[:layout] = true unless options.key?(:layout) filter_options = options.extract!(:if, :unless).merge(:only => actions) cache_options = options.extract!(:layout, :cache_path).merge(:store_options => options) around_filter ActionCacheFilter.new(cache_options), filter_options end end def _save_fragment(name, options) return unless caching_allowed? content = response_body content = content.join if content.is_a?(Array) write_fragment(name, content, options) end protected def expire_action(options = {}) return unless cache_configured? actions = options[:action] if actions.is_a?(Array) actions.each {|action| expire_action(options.merge(:action => action)) } else expire_fragment(ActionCachePath.new(self, options, false).path) end end class ActionCacheFilter #:nodoc: def initialize(options, &block) @cache_path, @store_options, @cache_layout = options.values_at(:cache_path, :store_options, :layout) end def filter(controller) path_options = if @cache_path.respond_to?(:call) controller.instance_exec(controller, &@cache_path) else @cache_path end cache_path = ActionCachePath.new(controller, path_options || {}) body = controller.read_fragment(cache_path.path, @store_options) unless body controller.action_has_layout = false unless @cache_layout yield controller.action_has_layout = true body = controller._save_fragment(cache_path.path, @store_options) end body = controller.render_to_string(:text => body, :layout => true) unless @cache_layout controller.response_body = body controller.content_type = Mime[cache_path.extension || :html] end end class ActionCachePath attr_reader :path, :extension # If +infer_extension+ is true, the cache path extension is looked up from the request's # path & format. This is desirable when reading and writing the cache, but not when # expiring the cache - expire_action should expire the same files regardless of the # request format. def initialize(controller, options = {}, infer_extension = true) if infer_extension @extension = controller.params[:format] options.reverse_merge!(:format => @extension) if options.is_a?(Hash) end path = controller.url_for(options).split(%r{://}).last @path = normalize!(path) end private def normalize!(path) path << 'index' if path[-1] == ?/ path << ".#{extension}" if extension and !path.ends_with?(extension) URI.unescape(path) end end end end end