Time delta addition in the sync process to avoid data loss during sync with unaccurate datetime

README.md

@@ -0,0 +1,24 @@
+HTML5 Notepad App
+by Kaspars Dambis (http://konstruktors.com)
+Fork by Benoît HERVIER (http://khertan.net)
+
+Fork addition :
+============
+*  Added support for devices without accurate time set, by adding a time delta to
+the synchronization process.
+*  Created a QML Harmattan client for use on Nokia n950 and Nokia n9
+
+Planned feature :
+============
+* Multi account support
+
+Installation
+============
+
+1. Upload files to your server
+2. Rename 'entries' folder to something random and harder to guess
+3. Make that folder writable (CHMOD 0777)
+4. Edit sync.php and specify your new DATA_DIR (the one you just renamed)
+5. In sync.php change username and password to something unique
+6. Done!
+

cache.manifest.php

@@ -1,6 +1,6 @@
 <?php header('Content-Type: text/cache-manifest'); ?>
 CACHE MANIFEST
-# v20121
+# v20122
 
 CACHE:
 index.html
@@ -14,4 +14,4 @@
 
 NETWORK:
 sync.php
-logout.php
+logout.php

index.html

@@ -228,6 +228,7 @@
 
 	function sync() {
 		if (navigator.onLine) {
+		    localStorage.setItem('clientime', (new Date().getTime() + ''));
 			$.post('sync.php', localStorage, function(data) {
 				console.log(data);
 				localStorage.setItem('index', JSON.stringify(data.index));
@@ -276,7 +277,7 @@
 			if (title === '')
 				title = 'Untitled';
 			if (val['timestamp'] !== 0)
-				$items.push('<li class="e-' + key + '"><a class="edit" href="#' + key + '">' + title + '</a> <time></time> <a class="delete" href="#' + key + '">-</a></li>');
+				$items.push('<li class="e-' + key + '"><a class="edit" href="#' + key + '">' + title + '</a> <time>'+ (new Date(parseInt(val['timestamp']))) + ' </time> <a class="delete" href="#' + key + '">-</a></li>');
   		});
   		$('#entries ul').hide().html($items.reverse().join('')).show();
 	}
@@ -306,4 +307,4 @@
 <!-- Could Pad HTML5 App by Kaspars Dambis / http://konstruktors.com/cloud-notepad-html5 -->
 
 </body>
-</html>
+</html>

sync.php

@@ -3,9 +3,29 @@
 error_reporting(E_ERROR);
 
 define('DATA_DIR', 'entries'); // use this to protect files from being publicly viewable
-define("USERNAME", 'demo');
+define('USERNAME', 'demo');
 define('PASSWORD', 'demo');
 
+// Parse incoming data
+if (isset($_POST['clientTime'])) {
+    $time_delta = time() - bigintval($_POST['clientTime']);
+    unset($_POST['clientTime']);}
+else {
+    $time_delta = 0;}
+
+if (isset($_SERVER['HTTP_AUTHORIZATION']) && preg_match('/Basic\s+(.*)$/i', $_SERVER['HTTP_AUTHORIZATION'], $matches)) {
+    list($name, $password) = explode(':', base64_decode($matches[1]));
+    $_SERVER['PHP_AUTH_USER'] = strip_tags($name);
+    $_SERVER['PHP_AUTH_PW'] = strip_tags($password);
+}
+
+//set http auth headers for apache+php-cgi work around if variable gets renamed by apache
+if (isset($_SERVER['REDIRECT_HTTP_AUTHORIZATION']) && preg_match('/Basic\s+(.*)$/i', $_SERVER['REDIRECT_HTTP_AUTHORIZATION'], $matches)) {
+    list($name, $password) = explode(':', base64_decode($matches[1]));
+    $_SERVER['PHP_AUTH_USER'] = strip_tags($name);
+    $_SERVER['PHP_AUTH_PW'] = strip_tags($password);
+}
+
 if (($_SERVER['PHP_AUTH_USER'] !== USERNAME) || ($_SERVER['PHP_AUTH_PW'] !== PASSWORD)) {
     header('WWW-Authenticate: Basic realm="Cloud Notes"');
     header('HTTP/1.0 401 Unauthorized');
@@ -14,8 +34,6 @@
 
 header('Content-type: application/json; charset=utf-8');
 
-// Parse incoming data
-
 $remote_index = (array)json_decode(stripslashes($_POST['index']), true);
 unset($_POST['index']);
 $remote_entries = $_POST;
@@ -46,23 +64,27 @@
 			delete_entry($id);
 			unset($remote_index[$id]);
 			unset($remote_entries[$id]);
-		} elseif ($item['timestamp'] > $local_index[$id]['timestamp']) {
+		} elseif (strval(bigintval($item['timestamp'])) - $time_delta > $local_index[$id]['timestamp']) {
 			// Remote entry is newer, replace it and don't send it back
 			$local_index[$id] = $item;
+			$local_index[$id]['timestamp'] = strval(bigintval($local_index[$id]['timestamp']) - $time_delta); 
 			store_entry($id, $_POST[$id]);
 			unset($remote_entries[$id]);
 			unset($local_entries[$id]);
-		} elseif ($item['timestamp'] == $local_index[$id]['timestamp']) {
+		} elseif (strval(bigintval($item['timestamp'])) - $time_delta == $local_index[$id]['timestamp']) {
 			// Local entry is already the latest, don't send it back
 			unset($remote_entries[$id]);
 			unset($local_entries[$id]);
 		} else {
 			// Local entry is newer, send it back
 			$remote_index[$id] = $local_index[$id];
+			$remote_index[$id]['timestamp'] = strval(bigintval($remote_index[$id]['timestamp']) + $time_delta); 
 			$remote_entries[$id] = get_entry($id);
+
 		}
 	} else {
 		$local_index[$id] = $remote_index[$id];
+		$local_index[$id]['timestamp'] = strval(bigintval($local_index[$id]['timestamp']) - $time_delta); 
 		store_entry($id, $_POST[$id]);
 		unset($remote_entries[$id]);
 	}
@@ -73,6 +95,7 @@
 	if ($local_index[$id]['timestamp'] !== 0) {
 		$remote_entries[$id] = get_entry($id);
 		$remote_index[$id] = $local_index[$id];
+		$remote_index[$id]['timestamp'] = strval(bigintval($remote_index[$id]['timestamp']) + $time_delta); 
 	} else {
 		unset($remote_entries[$id]);
 		unset($remote_index[$id]);
@@ -87,6 +110,18 @@
 
 // Helpers
 
+function bigintval($value) {
+  $value = trim($value);
+  if (ctype_digit($value)) {
+    return $value;
+  }
+  $value = preg_replace("/[^0-9](.*)$/", '', $value);
+  if (ctype_digit($value)) {
+    return $value;
+  }
+  return 0;
+}
+
 function get_entry($id) {
 	$file = DATA_DIR . '/' . $id;
 	if (file_exists($file)) {
@@ -136,4 +171,4 @@ function get_entries() {
 		return json_encode($entries);
 }
 
-?>
+?>