- E
- F
- S
Sets a HTTP 1.1 Cache-Control header. Defaults to issuing a
private
instruction, so that intermediate caches must not
cache the response.
expires_in 20.minutes
expires_in 3.hours, public: true
expires_in 3.hours, public: true, must_revalidate: true
This method will overwrite an existing Cache-Control header. See www.w3.org/Protocols/rfc2616/rfc2616-sec14.html for more possibilities.
The method will also ensure a HTTP Date header for client compatibility.
# File actionpack/lib/action_controller/metal/conditional_get.rb, line 176 def expires_in(seconds, options = {}) response.cache_control.merge!( :max_age => seconds, :public => options.delete(:public), :must_revalidate => options.delete(:must_revalidate) ) options.delete(:private) response.cache_control[:extras] = options.map {|k,v| "#{k}=#{v}"} response.date = Time.now unless response.date? end
Sets a HTTP 1.1 Cache-Control header of no-cache
so no caching
should occur by the browser or intermediate caches (like caching proxy
servers).
Sets the etag
, last_modified
, or both on the
response and renders a 304 Not Modified
response if the
request is already fresh.
Parameters:
-
:etag
. -
:last_modified
. -
:public
By default the Cache-Control header is private, set this totrue
if you want your application to be cachable by other devices (proxy caches). -
:template
By default, the template digest for the current controller/action is included in ETags. If the action renders a different template, you can include its digest instead. If the action doesn't render a template at all, you can passtemplate: false
to skip any attempt to check for a template digest.
Example:
def show
@article = Article.find(params[:id])
fresh_when(etag: @article, last_modified: @article.created_at, public: true)
end
This will render the show template if the request isn't sending a
matching ETag or If-Modified-Since header and just a 304 Not
Modified
response if there's a match.
You can also just pass a record where last_modified
will be
set by calling updated_at
and the etag
by passing
the object itself.
def show
@article = Article.find(params[:id])
fresh_when(@article)
end
When passing a record, you can still set whether the public header:
def show
@article = Article.find(params[:id])
fresh_when(@article, public: true)
end
When rendering a different template than the default controller/action style, you can indicate which digest to include in the ETag:
before_action { fresh_when @article, template: 'widgets/show' }
# File actionpack/lib/action_controller/metal/conditional_get.rb, line 80 def fresh_when(record_or_options, additional_options = {}) if record_or_options.is_a? Hash options = record_or_options options.assert_valid_keys(:etag, :last_modified, :public, :template) else record = record_or_options options = { etag: record, last_modified: record.try(:updated_at) }.merge!(additional_options) end response.etag = combine_etags(options) if options[:etag] || options[:template] response.last_modified = options[:last_modified] if options[:last_modified] response.cache_control[:public] = true if options[:public] head :not_modified if request.fresh?(response) end
Sets the etag
and/or last_modified
on the
response and checks it against the client request. If the request
doesn't match the options provided, the request is considered stale and
should be generated from scratch. Otherwise, it's fresh and we
don't need to generate anything and a reply of 304 Not
Modified
is sent.
Parameters:
-
:etag
. -
:last_modified
. -
:public
By default the Cache-Control header is private, set this totrue
if you want your application to be cachable by other devices (proxy caches). -
:template
By default, the template digest for the current controller/action is included in ETags. If the action renders a different template, you can include its digest instead. If the action doesn't render a template at all, you can passtemplate: false
to skip any attempt to check for a template digest.
Example:
def show
@article = Article.find(params[:id])
if stale?(etag: @article, last_modified: @article.created_at)
@statistics = @article.really_expensive_call
respond_to do |format|
# all the supported formats
end
end
end
You can also just pass a record where last_modified
will be
set by calling updated_at
and the etag
by passing
the object itself.
def show
@article = Article.find(params[:id])
if stale?(@article)
@statistics = @article.really_expensive_call
respond_to do |format|
# all the supported formats
end
end
end
When passing a record, you can still set whether the public header:
def show
@article = Article.find(params[:id])
if stale?(@article, public: true)
@statistics = @article.really_expensive_call
respond_to do |format|
# all the supported formats
end
end
end
When rendering a different template than the default controller/action style, you can indicate which digest to include in the ETag:
def show
super if stale? @article, template: 'widgets/show'
end