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rails--rails/actionpack/lib/action_controller/caching/actions.rb
Michael Koziarski 2f4aaed7b3 Disable the Accept header by default
The accept header is poorly implemented by browsers and causes strange errors when used on public sites where crawlers make requests too.  You should use formatted urls (e.g. /people/1.xml) to support API clients. Alternatively to re-enable it you need to set:

config.action_controller.use_accept_header = true

A special case remains for ajax requests which will have a javascript format for the base resource (/people/1) if the X-Requested-With header is present.  This lets ajax pages still use format.js despite there being no params[:format]
2008-07-07 07:31:49 +02:00

176 lines
7.8 KiB
Ruby

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. <tt>http://david.somewhere.com/lists</tt> and <tt>http://david.somewhere.com/lists.xml</tt>
# are treated like separate requests and so are cached separately. Keep in mind when expiring an action cache that <tt>:action => 'lists'</tt> is not the same
# as <tt>:action => 'list', :format => :xml</tt>.
#
# 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.new { |c| !c.request.format.json? } # cache if is not a JSON request
# caches_action :show, :cache_path => { :project => 1 }, :expires_in => 1.hour
# caches_action :feed, :cache_path => Proc.new { |controller|
# controller.params[:user_id] ?
# controller.send(:user_list_url, c.params[:user_id], c.params[:id]) :
# controller.send(:list_url, c.params[:id]) }
# end
#
# If you pass :layout => false, it will only cache your action content. It is useful when your layout has dynamic information.
#
module Actions
def self.included(base) #:nodoc:
base.extend(ClassMethods)
base.class_eval do
attr_accessor :rendered_action_cache, :action_cache_path
end
end
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!
filter_options = { :only => actions, :if => options.delete(:if), :unless => options.delete(:unless) }
cache_filter = ActionCacheFilter.new(:layout => options.delete(:layout), :cache_path => options.delete(:cache_path), :store_options => options)
around_filter(cache_filter, filter_options)
end
end
protected
def expire_action(options = {})
return unless cache_configured?
if options[:action].is_a?(Array)
options[:action].dup.each do |action|
expire_fragment(ActionCachePath.path_for(self, options.merge({ :action => action }), false))
end
else
expire_fragment(ActionCachePath.path_for(self, options, false))
end
end
class ActionCacheFilter #:nodoc:
def initialize(options, &block)
@options = options
end
def before(controller)
cache_path = ActionCachePath.new(controller, path_options_for(controller, @options.slice(:cache_path)))
if cache = controller.read_fragment(cache_path.path, @options[:store_options])
controller.rendered_action_cache = true
set_content_type!(controller, cache_path.extension)
options = { :text => cache }
options.merge!(:layout => true) if cache_layout?
controller.send!(:render, options)
false
else
controller.action_cache_path = cache_path
end
end
def after(controller)
return if controller.rendered_action_cache || !caching_allowed(controller)
action_content = cache_layout? ? content_for_layout(controller) : controller.response.body
controller.write_fragment(controller.action_cache_path.path, action_content, @options[:store_options])
end
private
def set_content_type!(controller, extension)
controller.response.content_type = Mime::Type.lookup_by_extension(extension).to_s if extension
end
def path_options_for(controller, options)
((path_options = options[:cache_path]).respond_to?(:call) ? path_options.call(controller) : path_options) || {}
end
def caching_allowed(controller)
controller.request.get? && controller.response.headers['Status'].to_i == 200
end
def cache_layout?
@options[:layout] == false
end
def content_for_layout(controller)
controller.response.layout && controller.response.template.instance_variable_get('@content_for_layout')
end
end
class ActionCachePath
attr_reader :path, :extension
class << self
def path_for(controller, options, infer_extension=true)
new(controller, options, infer_extension).path
end
end
# When true, infer_extension will look up the cache path extension 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 and options.is_a? Hash
request_extension = extract_extension(controller.request)
options = options.reverse_merge(:format => request_extension)
end
path = controller.url_for(options).split('://').last
normalize!(path)
if infer_extension
@extension = request_extension
add_extension!(path, @extension)
end
@path = URI.unescape(path)
end
private
def normalize!(path)
path << 'index' if path[-1] == ?/
end
def add_extension!(path, extension)
path << ".#{extension}" if extension and !path.ends_with?(extension)
end
def extract_extension(request)
# Don't want just what comes after the last '.' to accommodate multi part extensions
# such as tar.gz.
extension = request.path[/^[^.]+\.(.+)$/, 1]
# If there's no extension in the path, check request.format
if extension.nil?
extension = request.cache_format
end
extension
end
end
end
end
end