Firebase 3方式数据绑定无法按预期工作 [英] Firebase 3 way data binding not working as expected

问题描述

我有一个返回Firebase引用的AngularJS服务.

I have an AngularJS service that returns a firebase ref.

.factory('sessionManager', ['$firebase','$scope', function($firebase){
    var ref=new Firebase('https://telechat.firebaseio.com/sessions');
    return $firebase(ref);
  }])

在控制器中，我添加了依赖项并称为$bind.

In the controller, I have added the dependency and called $bind.

$scope.items=sessionManager;
$scope.items.$bind($scope,'sessions').then(function(unbind){
      unbind();
    });

但是当我将其打印到控制台时，返回的数据除了数据数组之外，还具有诸如$add，$set等的功能的集合.

But when I print it to the console, the returned data has a collection of functions like $add , $set ,.. etc in addition to the array of data.

为什么会这样?我做错了吗?

Why is this occurring? Am I doing it the wrong way?

推荐答案

如果我正确地阅读了该问题，您可能会觉得$ bind()是将$ firebase对象转换为原始数据数组的印象或对象.本质上，$ firebase实例和$ bind之间的唯一区别是数据是本地更改，它们是自动从Angular推回Firebase的.而当您使用不带$ bind的$ firebase时，则需要调用$ save来推送本地更改.

If I'm reading the question correctly, you may be under the impression that $bind() is a transformation of the $firebase object into a raw data array or object. In essence, the only difference between a $firebase instance and $bind is that data is local changes are automagically pushed back to Firebase from Angular. Whereas, when you use $firebase without $bind, you need to call $save to push local changes.

请记住，$ firebase是Firebase API的包装器，而不是简单的数据数组，在大多数情况下，您仍可以将其视为原始数据.

Keeping in mind that $firebase is a wrapper on the Firebase API and not a simple data array, you can still treat it like raw data in most cases.

要迭代Firebase对象中的数据，可以使用ngRepeat:

To iterate data in a Firebase object, you can use ngRepeat:

<li ng-repeat="(key, item) in $sessions">{{item|json}}</li>

或者如果您想应用依赖于数组的过滤器:

Or if you want to apply filters that depend on arrays:

<li ng-repeat="(key, item) in $sessions | orderByPriority | filter:searchText">

或者在使用$ getIndex的控制器中:

Or in a controller using $getIndex:

angular.forEach($scope.sessions.$getIndex(), function(key) {
    console.log(key, $scope.sessions[key]);
});

已修改的$ add/$ update/etc方法是 $ firebase对象的API的一部分. 文档和

The $add/$update/etc methods mentoined are part of the $firebase object's API. The documentation and the tutorial should be great primers for understanding this process.

这也是API的一部分，该API正在不断发展以更好地匹配Angular的做事方式和用户的反馈.

This is also a part of the API that is continuing to evolve to better match the Angular way of doing things and feedback from users.

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