使用 polymefire firebase-query 元素没有返回数据

Question

我正在创建一个 dom 模块来在 div 中显示我的 firebase 数据。我在 https://www.youtube.com/watch?v=9AHDSGitDP0&t=639s but the firebase-query component is not pulling in the data. No data appears in the console other than my signed in user data and there are no errors. I saw that other people had issues pulling in data with polymerfire and I tried the solution here but no luck:

观看了 Polycast 视频

有人可以帮忙吗？

在我的 html 主页面中，我有以下内容：

<head>
    <meta charset="utf-8">
    <link rel="stylesheet" href="stylesheets/style.css">
    <link rel="import" href="../bower_components/polymer/polymer.html">
    <link rel="import" href="../bower_components/polymerfire/polymerfire.html">
    <link rel="import" href="../bower_components/polymerfire/firebase-app.html">
    <link rel="import" href="../bower_components/polymerfire/firebase-database-script.html"> 
    <link rel="import" href="../bower_components/webcomponentsjs/webcomponents-lite.js">
    <link rel="import" href="elements/browse-events.html"> <!-- my custom component -->
</head>

<body>
            <firebase-app
                api-key=""
                auth-domain=""
                database-url=""
                project-id=""
                storage-bucket=""
                messaging-sender-id="">
            </firebase-app>

            <!-- my custom component -->
            <browse-events></browse-events>

</body>

这是我的组件文件中的代码 (browse-events.html)

<!-- dependencies -->
<link rel="import" href="../bower_components/polymer/polymer.html">
<link rel="import" href="../bower_components/polymerfire/polymerfire.html">
<link rel="import" href="../bower_components/polymerfire/firebase-app.html">
<link rel="import" href="../bower_components/polymerfire/firebase-database-script.html">
<link rel="import" href="../bower_components/polymerfire/firebase-database-behavior.html">
<link rel="import" href="../bower_components/polymerfire/firebase-query.html">

<dom-module id="browse-events"> 
    <template>
        <firebase-query
                        id="query-all"
                        app-name="authtest-54513"
                        path="/events"
                        data="{{events}}">
        </firebase-query>

        <template is="dom-repeat" items="[[events]]" as="event">
            <div> 
                <h1>[[event.title]]</h1>
            </div>
        </template>
    </template>

    <script>
        Polymer({
            is:'browse-events',
            properties: {
                events: {
                    type: Object
                }
            }
        });
    </script>
</dom-module>

Answer 1

如果您在 firebase-query 中使用 app-name，则需要在 firebase-app 中指定 name。如果您在应用中只使用一个 firebase-app，则可以在 firebase-app 中省略 name，在其他 polymerfire 元素中省略 app-name。

属性 events 可能是数组而不是对象：

If the child nodes of the query are objects (most cases), data will be an array of those objects with an extra $key field added to represent the key. If the child nodes are non-object leaf values, data will be an array of objects of the structure {$key: key, $val: val}. https://github.com/firebase/polymerfire/blob/master/firebase-query.html

附带说明：您只需要在 browse-events 元素中导入 firebase-query。 Firebase-query 会将它需要的脚本导入运行本身。（与主 html 页面中的 firebase-app 相同）

使用 polymefire firebase-query 元素没有返回数据

No data returned using polymefire firebase-query element

javascript

firebase

polymer

firebase-realtime-database

polymerfire