Initial Release of the calendar plugin

dav/SabreDAV/lib/Sabre/HTTP/Util.php

@@ -0,0 +1,82 @@
+<?php
+
+/**
+ * HTTP utility methods
+ *
+ * @package Sabre
+ * @subpackage HTTP
+ * @copyright Copyright (C) 2007-2012 Rooftop Solutions. All rights reserved.
+ * @author Evert Pot (http://www.rooftopsolutions.nl/)
+ * @author Paul Voegler
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Sabre_HTTP_Util {
+
+    /**
+     * Parses a RFC2616-compatible date string
+     *
+     * This method returns false if the date is invalid
+     *
+     * @param string $dateHeader
+     * @return bool|DateTime
+     */
+    static function parseHTTPDate($dateHeader) {
+
+        //RFC 2616 section 3.3.1 Full Date
+        //Only the format is checked, valid ranges are checked by strtotime below
+        $month = '(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)';
+        $weekday = '(Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday)';
+        $wkday = '(Mon|Tue|Wed|Thu|Fri|Sat|Sun)';
+        $time = '[0-2]\d(\:[0-5]\d){2}';
+        $date3 = $month . ' ([1-3]\d| \d)';
+        $date2 = '[0-3]\d\-' . $month . '\-\d\d';
+        //4-digit year cannot begin with 0 - unix timestamp begins in 1970
+        $date1 = '[0-3]\d ' . $month . ' [1-9]\d{3}';
+
+        //ANSI C's asctime() format
+        //4-digit year cannot begin with 0 - unix timestamp begins in 1970
+        $asctime_date = $wkday . ' ' . $date3 . ' ' . $time . ' [1-9]\d{3}';
+        //RFC 850, obsoleted by RFC 1036
+        $rfc850_date = $weekday . ', ' . $date2 . ' ' . $time . ' GMT';
+        //RFC 822, updated by RFC 1123
+        $rfc1123_date = $wkday . ', ' . $date1 . ' ' . $time . ' GMT';
+        //allowed date formats by RFC 2616
+        $HTTP_date = "($rfc1123_date|$rfc850_date|$asctime_date)";
+
+        //allow for space around the string and strip it
+        $dateHeader = trim($dateHeader, ' ');
+        if (!preg_match('/^' . $HTTP_date . '$/', $dateHeader))
+            return false;
+
+        //append implicit GMT timezone to ANSI C time format
+        if (strpos($dateHeader, ' GMT') === false)
+            $dateHeader .= ' GMT';
+
+
+        $realDate = strtotime($dateHeader);
+        //strtotime can return -1 or false in case of error
+        if ($realDate !== false && $realDate >= 0)
+            return new DateTime('@' . $realDate, new DateTimeZone('UTC'));
+
+    }
+
+    /**
+     * Transforms a DateTime object to HTTP's most common date format.
+     *
+     * We're serializing it as the RFC 1123 date, which, for HTTP must be
+     * specified as GMT.
+     *
+     * @param DateTime $dateTime
+     * @return string
+     */
+    static function toHTTPDate(DateTime $dateTime) {
+
+        // We need to clone it, as we don't want to affect the existing
+        // DateTime.
+        $dateTime = clone $dateTime;
+        $dateTime->setTimeZone(new DateTimeZone('GMT'));
+        return $dateTime->format('D, d M Y H:i:s \G\M\T');
+
+    }
+
+}