dart - 聚合物数据绑定(bind)不起作用

Question

我正在尝试获取 <core-menu>与 Dart 合作。它显示正常，但 selectedIndex属性未更新。
以下代码适用于 PolymerJS，但在 Dart 版本中 selectedIndex未更新(​​<core-menu selectedIndex="{{selectedMenuIndex}}"...>)

我希望 {{selectedMenuIndex}}可在 <core-animated-pages> 中获得标记但 {{selectedMenuIndex}}变量为空。它没有得到更新。 .dart文件的 var 声明如下:

@observable num selectedMenuIndex = 0;

这是 .html 代码:

<link rel="import" href="packages/polymer/polymer.html">
<link rel="import" href="packages/core_elements/core_drawer_panel.html">
<link rel="import" href="packages/core_elements/core_menu.html">
<link rel="import" href="packages/core_elements/core_selector.html">
<link rel="import" href="packages/core_elements/core_item.html">
<link rel="import" href="packages/core_elements/core_icon_button.html">
<link rel="import" href="packages/paper_elements/paper_icon_button.html">
<link rel="import" href="packages/core_elements/core_toolbar.html">
<link rel="import" href="packages/core_elements/core_header_panel.html">
<link rel="import" href="packages/paper_elements/core_animated_pages.html">

<polymer-element name="test-app">

<template>
<!-- [START html] -->
<core-drawer-panel id="drawerPanel">

    <core-header-panel drawer>
        <core-toolbar id="navheader'">
            <span>Menu</span>
        </core-toolbar>
        <core-menu selected="0" selectedIndex="{{selectedMenuIndex}}" id="coreMenu" on-click="{{togglePanelButton}}">
            <core-item icon="settings" label="One"></core-item>
            <core-item icon="search" label="Two"></core-item>
        </core-menu>
    </core-header-panel>

    <core-header-panel main>
        <core-toolbar id="mainheader">
            <paper-icon-button id="navicon" icon="menu" on-click="{{ togglePanelButton }}"></paper-icon-button>
            <span flex>Title</span>
        </core-toolbar>
        <core-animated-pages selected="{{selectedMenuIndex}}" notap id="core_animated_pages" transitions="slide-from-right">
            <section class="content-section">
                Section 1
            </section>
            <section class="content-section">
                Section 2
            </section>
        </core-animated-pages>
    </core-header-panel>

</core-drawer-panel>
<!-- [END html]-->
</template>

<script type="application/dart" src="testapp.dart"></script>
</polymer-element>

你们是不是也有数据问题，还是我做错了什么？

更新:我在这里提交了一个错误报告:
https://code.google.com/p/dart/issues/detail?id=19794

Answer 1

我从 Dart Polymer 小组得到了答案:
https://code.google.com/p/dart/issues/detail?id=19794

似乎与 core_elements 的 2-way 绑定(bind)存在问题。