/**
* Sets the number of seconds before a page cached on a browser expires.
*
* @throws Phoenix\Exceptions\FailureException if HTTP headers have been sent
* @param string|int|\DateTime $time
* [optional] default null means no cache, otherwise it is cache time; supported format here http://php.net/manual/en/datetime.formats.php
* @return void
*/
public final function setExpiration($time = null)
{
if (empty($time)) {
// no cache
$this->setHeader("Cache-Control", "s-maxage=0, max-age=0, must-revalidate");
$this->setHeader("Expires", "Tue, 1 Jan 1991 00:00:00 GMT");
return;
}
$time = DateTime::from($time);
$this->setHeader("Cache-Control", "max-age=" . ($time->format("U") - time()));
$this->setHeader("Expires", DateTime::formatHttpDate($time));
return;
}
