Data binding 聚合物1.x：与Firebase的深度链接数据绑定

我想通过

Firebase文档

元素将

设置

对象数据绑定到我的Firebase中的深度链接，如下所示：

my-element.html

<firebase-document location="<my-firebase>/users/uid/settings"
                   data="{{settings}}"</firebase-document>
...
<paper-input label="Name" value="{{settings.name}}"></paper-input>
<paper-input label="Email" value="{{settings.email}}"></paper-input>
...
settings: {
  type: Object,
  notify: true,
  value: {},
...

<firebase-document location="https://my-firebase.firebaseio.com/settings"
  data="{{settings}}" on-firebase-value="_firebaseLoaded"></firebase-document>
...
<paper-input label="Name" value="{{settings.name}}"></paper-input>
...
settings: {
  type: Object,
  notify: true,
  value: {},
}
...
_firebaseLoaded: function() {
  if(!this.settings) {
    this.set('settings', {});
  }
},

---

操作代码仅用于编辑现有记录。在端点处创建新记录不起作用（例如，在本例中为
/settings
）

为此，必须在Firebase端点不存在初始值时添加初始值，如下所示：

使用firebase value=“\u firebaseLoaded”

上的

测试是否存在初始firebase值
如果没有，（有条件地）在
\u firebaseload
方法中添加一个
my-element.html
<firebase-document location="<my-firebase>/users/uid/settings"
                   data="{{settings}}"</firebase-document>
...
<paper-input label="Name" value="{{settings.name}}"></paper-input>
<paper-input label="Email" value="{{settings.email}}"></paper-input>
...
settings: {
  type: Object,
  notify: true,
  value: {},
...

<firebase-document location="https://my-firebase.firebaseio.com/settings"
  data="{{settings}}" on-firebase-value="_firebaseLoaded"></firebase-document>
...
<paper-input label="Name" value="{{settings.name}}"></paper-input>
...
settings: {
  type: Object,
  notify: true,
  value: {},
}
...
_firebaseLoaded: function() {
  if(!this.settings) {
    this.set('settings', {});
  }
},


...
...
设置：{
类型：对象，
通知：正确，
值：{}，
}
...
_firebaseLoaded:函数（）{
如果（！this.settings）{
this.set（'settings'，{}）；
}
},