Feature: Added plugin for synchronising client time with the server

serverdate/strophe.serverdate.js

@@ -0,0 +1,58 @@
+//= require <strophe>
+
+/* serverdate plugin
+**
+** This plugin syncs a local clock to the servers using the response header
+** on the BOSH connection
+**
+*/
+
+var ServerDate = function(){
+  if( arguments.length === 0 ){
+    return new Date( new Date().valueOf() + ServerDate.skew );
+  }
+  else if ( arguments.length === 1 ){
+    // Covers case where a string is passed in
+    return new Date( arguments[0] );
+  }
+  else {
+    return new Date( Date.UTC.apply( null, arguments ) + ((new Date()).getTimezoneOffset() * 60000) );    
+  }
+};
+ServerDate.parse = Date.parse;
+ServerDate.UTC   = Date.UTC;
+ServerDate.now   = function(){ return (new ServerDate()).valueOf(); };
+ServerDate.skew  = 0;
+
+Strophe.addConnectionPlugin('serverdate', {
+  init: function(connection){    
+    Strophe.Request.prototype._newXHR = function () {
+      var xhr = null;
+      if (window.XMLHttpRequest) {
+        xhr = new XMLHttpRequest();
+        if (xhr.overrideMimeType) {
+          xhr.overrideMimeType("text/xml");
+        }
+      } else if (window.ActiveXObject) {
+        xhr = new ActiveXObject("Microsoft.XMLHTTP");
+      }
+
+      var handler = this.func.prependArg(this);
+
+      xhr.onreadystatechange = function(){
+        if(this.readyState == 2){
+          var header = this.getResponseHeader('Date');
+          var server_date = new Date(header);
+          if ( header && server_date != 'Invalid Date' ){
+            system_date = new Date();
+            skew_ms = server_date - system_date;
+            ServerDate.skew = skew_ms;
+          }
+        }
+        handler();
+      };
+
+      return xhr;
+    };
+  }
+});