Update TodoMVC based on https://github.com/polymer/todomvc

samples/third_party/todomvc/web/router_options.dart

-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-library todomvc.web.router_options;
-
-import 'dart:html';
-import 'package:polymer/polymer.dart';
-
-/**
- * Given a set of child links to this page, this will add the "selected" CSS
- * class to the link that matches window.location.hash.
- *
- * For example, if the current window.location.hash is "#/completed" and we
- * have a tag like `<a href="#/completed">` it will get the class
- * `class="selected"`, and other links will have that CSS class removed.
- */
-@CustomTag('router-options')
-class RouterOptions extends UListElement with Polymer, Observable {
-  factory RouterOptions() => new Element.tag('ul', 'router-options');
-
-  RouterOptions.created() : super.created() {
-    polymerCreated();
-  }
-
-  bool get applyAuthorStyles => true;
-  var _sub;
-
-  void enteredView() {
-    super.enteredView();
-
-    var anchors = this.querySelectorAll('a');
-
-    _updateHash(records) {
-      var hash = window.location.hash;
-      if (hash == '') hash = '#/';
-      for (var a in anchors) {
-        if (a.hash == hash) {
-          a.classes.add('selected');
-        } else {
-          a.classes.remove('selected');
-        }
-      }
-    }
-
-    _updateHash(null);
-    _sub = windowLocation.changes.listen(_updateHash);
-  }
-
-  void leftView() {
-    _sub.cancel();
-    super.leftView();
-  }
-}