Module: ActionController::Caching::Actions
- Defined in:
- lib/action_controller/caching.rb
Overview
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 :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 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
.
Defined Under Namespace
Modules: ClassMethods Classes: ActionCacheFilter, ActionCachePath
Class Method Summary collapse
-
.included(base) ⇒ Object
:nodoc:.
Instance Method Summary collapse
Class Method Details
.included(base) ⇒ Object
:nodoc:
164 165 166 167 |
# File 'lib/action_controller/caching.rb', line 164 def self.included(base) #:nodoc: base.extend(ClassMethods) base.send(:attr_accessor, :rendered_action_cache) end |
Instance Method Details
#expire_action(options = {}) ⇒ Object
176 177 178 179 180 181 182 183 184 185 |
# File 'lib/action_controller/caching.rb', line 176 def expire_action( = {}) return unless perform_caching if [:action].is_a?(Array) [:action].dup.each do |action| expire_fragment(ActionCachePath.path_for(self, .merge({ :action => action }))) end else expire_fragment(ActionCachePath.path_for(self, )) end end |