30 day expire if checksum is present

1 files changed, 4 insertions, 3 deletions

diff --git a/itjs.php b/itjs.php
index 3fc5441..32267da 100644
--- a/itjs.php
+++ b/itjs.php
@@ -65,12 +65,13 @@ else if (!it::match('\.html$', $file))
 	header("Content-Type: application/x-javascript; charset=$charset");
 }
 
-@header("Etag: alwaysvalid");
+@header("Etag: alwaysvalid"); # we have checksums in the url. client should always keep the version he downloaded along with the html
 
 if (!preg_match('/Opera/', $_SERVER['HTTP_USER_AGENT']) && it::is_live() && !$_REQUEST['retry'])
 {
-	header("Cache-Control: max-age=604800, private"); # proxies should not cache since contents of same url can differ between browsers
-	header("Expires: " . gmdate("D, d M Y H:i:s", time()+604800). " GMT");
+	$keeptime = $_REQUEST['s'] || $_REQUEST['c'] ? 86400*30 : 900; # long expire if checksum present
+	header("Cache-Control: max-age=$keeptime, private"); # proxies should not cache since contents of same url can differ between browsers
+	header("Expires: " . gmdate("D, d M Y H:i:s", time() + $keeptime). " GMT");
 }
 
 $data = itjs::strip($data);