This function can be used to set an absolute time for an expiration of a page. This is best used for pages with a long life that may be requested frequently. Due to problems in time synchronization between the client and the server, it is not totally reliable, especially for short-lived caches. The data must follow one of the acceptable HTTP date formats.
Refer to the W3 Protocols for more information:
The only parameter is the lifetime of this page in seconds.
Returns TRUE if the function is successful.
Returns FALSE if the function fails.
This will expire the content of the page immediately:
This will set the cache lifetime for this page to 10 minutes, and tell the browser that it absolutely must try to refresh the page after that time is up:
<$setMaxAge(600)$> <$setHttpHeader("Cache-Control", "must-revalidate")$>