Control client-side caching of this Pattern Page
The body of this tag is always empty.
yes, private, noheaders or no. If this attribute has the value 'yes'
then network devices are allowed to cache this page. If it is set to 'no' then the
page may not be cached. If the attribute is set to 'private' then only
the client device making the request may cache the results.
If set to noheaders then Whitebeam generates no cache headers and the application
can generate the headers it requires. This is the equivalent to calling
rb.page.cache() with no parameters.
Only used if 'cache' is set to either yes or private. In
both of these cases setting the 'max-age' attribute will cause the
Presentation Engine to generate a 'Max-Age' directive in the Cache-Control
HTTP header. If this attribute is not set then the Presentation Engine
set's neither the Max-Age directive or an 'Expires' header.
Tells the Presentation Engine which value to include in the
HTTP 'Last-Modified' header. The default is that this parameter
is set to 'now' (the time at this moment'). You can over-ride this
by setting this parameter to 'file' - meaning the time at which the
source Pattern Page was last modified.
This tag allows a Pattern Page to control the value in the HTTP header
that determines whether the page can be cached by the browser and/or any intermediate
device. By default the cache control header is set to "no cache" on
rhtm pages. However some pages, although generated dynamically, have contents
that seldom change (for example the page you are looking at now). This tag allows
you to override the default setting as in
There are yet other pages that - although basically static - are different for each user.
In this case you want to allow the client device to cache the content while preventing
intermediate devices from so doing. You can achieve this by setting the 'cache'
attribute to private,
To control caching to a finer level you can specify a 'max-age' for the page in cache
using the 'max-age' attribute. This specifies the number of seconds before the page should
be expired from conformant caches. If specified this value is used to construct a
max-age directive on the Cache-Control header and to create an Expires header.
Finally - you can specify the 'Last-Modified' header date for the page generated. This
is used hueristically by advanced web caches to derive how safe a cached page is. By default the
Presentation Engine inserts the current data and time. This attribute can be set to either
'now' or 'file'. If 'file' is specified then the date is taken from the last modified
date of the source Pattern Page being used to generate the web page.