Fixes #2002 adds ETag support to simple cache handler

Elgg · Jan 8, 2012 · d213db7 · d213db7
1 parent 3b496d9
commit d213db7
Showing 1 changed file with 13 additions and 8 deletions.
diff --git a/engine/handlers/cache_handler.php b/engine/handlers/cache_handler.php
@@ -60,26 +60,31 @@
 $type = $matches[1];
 $viewtype = $matches[2];
 $view = $matches[3];
+$ts = $matches[4];
+
+// If is the same ETag, content didn't changed.
+$etag = $ts;
+if (isset($_SERVER['HTTP_IF_NONE_MATCH']) && trim($_SERVER['HTTP_IF_NONE_MATCH']) == $etag) {
+	header("HTTP/1.1 304 Not Modified");
+	exit;
+}
 
 switch ($type) {
 	case 'css':
 		header("Content-type: text/css", true);
-		header('Expires: ' . date('r', strtotime("+6 months")), true);
-		header("Pragma: public", true);
-		header("Cache-Control: public", true);
-
 		$view = "css/$view";
 		break;
 	case 'js':
 		header('Content-type: text/javascript', true);
-		header('Expires: ' . date('r', strtotime("+6 months")), true);
-		header("Pragma: public", true);
-		header("Cache-Control: public", true);
-
 		$view = "js/$view";
 		break;
 }
 
+header('Expires: ' . date('r', strtotime("+6 months")), true);
+header("Pragma: public", true);
+header("Cache-Control: public", true);
+header("ETag: $etag");
+
 $filename = $dataroot . 'views_simplecache/' . md5($viewtype . $view);
 
 if (file_exists($filename)) {