Merge commit 'origin/core-1.0.2' into core

[platal.git] / include / platal.inc.php

diff --git a/include/platal.inc.php b/include/platal.inc.php
index 652dc92..badaef5 100644 (file)
--- a/include/platal.inc.php
+++ b/include/platal.inc.php
@@ -1,6 +1,6 @@
 <?php
 /***************************************************************************
- *  Copyright (C) 2003-2008 Polytechnique.org                              *
+ *  Copyright (C) 2003-2009 Polytechnique.org                              *
  *  http://opensource.polytechnique.org/                                   *
  *                                                                         *
  *  This program is free software; you can redistribute it and/or modify   *
@@ -21,6 +21,7 @@
 
 $TIME_BEGIN = microtime(true);
 
+require_once dirname(__FILE__) . '/version.inc.php';
 require_once dirname(__FILE__) . '/misc.inc.php';
 
 define('PERMS_EXT',   'ext');
@@ -175,5 +176,58 @@ function pl_entity_decode($text, $mode = ENT_COMPAT)
     return html_entity_decode($text, $mode, 'UTF-8');
 }
 
+/**
+ * Returns the path of a static content, including, when appropriate, the
+ * version number. This is used to avoid cross-version cache issues, by ensuiring
+ * that all static resources are served on a unique path.
+ */
+function pl_static_content_path($path, $filename)
+{
+    global $globals;
+    if (isset($globals) && isset($globals->version)) {
+        return $path . $globals->version . '/' . $filename;
+    } else {
+        return $path . $filename;
+    }
+}
+
+/**
+ * Adds content type headers; by default the encoding used is utf-8.
+ */
+function pl_content_headers($content_type, $encoding = 'utf-8')
+{
+    if (is_null($encoding)) {
+        header("Content-Type: $content_type");
+    } else {
+        header("Content-Type: $content_type; charset=$encoding");
+    }
+}
+
+/**
+ * Adds content type and caching headers for content generated by plat/al. The
+ * cache duration defaults to the global static_cache_duration. No encoding is
+ * applied by default.
+ */
+function pl_cached_content_headers($content_type, $encoding = null, $cache_duration = -1)
+{
+    global $globals;
+    $cache_duration = ($cache_duration < 0 ? $globals->static_cache_duration : $cache_duration);
+
+    header("Cache-Control: max-age=$cache_duration");
+    header("Expires: " . gmdate('D, d M Y H:i:s', time() + $cache_duration) . " GMT");
+    header("Pragma: ");
+    pl_content_headers($content_type, $encoding);
+}
+
+/**
+ * Same as above, but applying an expiration time suitable for cacheable dynamic
+ * content (eg. photos, logos, ...).
+ */
+function pl_cached_dynamic_content_headers($content_type, $encoding = null)
+{
+    global $globals;
+    pl_cached_content_headers($content_type, $encoding, $globals->dynamic_cache_duration);
+}
+
 // vim:set et sw=4 sts=4 sws=4 foldmethod=marker enc=utf-8:
 ?>