如果我重组数据以供使用，如何让 Firebase 自动更新它? [英] If I restructure data for use, how can I make Firebase automatically update it?

问题描述

如果我使用:

var ref = new Firebase("https://myURL.firebaseio.com/");                
var sync = $firebase(ref);                                
var firebaseData= sync.$asObject();

firebaseData 将随着 https://myURL.firebaseio.com/ 中的数据变化而变化.它们将保持同步.

firebaseData will change as data from https://myURL.firebaseio.com/ changes. They will be in sync.

如果我重组数据，并将其定义为一些新变量 var newStructure，我怎样才能让它与 https://myURL.firebaseio.com/ 同步或 firebaseData?

If I restructure data, and define it as some new variable var newStructure, how can I get it to sync with https://myURL.firebaseio.com/ or firebaseData?

有没有一种方法可以让我观察 firebaseData 中的变化并调用重组方法?

Is there a way I can watch for changes in firebaseData and recall the restructuring method?

有没有办法知道 firebaseData 中具体发生了什么变化，并且只对 newStructure 进行相关更改?

Is there a way to know what specifically changed in firebaseData and make only relevant changes to newStructure?

有没有一种方法可以让 newStructure 直接与 Firebase 同步，尽管使用不同的结构解析数据?

Is there a way that newStructure can sync directly with Firebase, albeit have data parsed with a different structure?

推荐答案

你的变量 firebaseData 代表你的 firebase 集合.

Your variable firebaseData represents your firebase collection.

您对 firebaseData 所做的所有更改都将跨连接同步:

All changes you make to firebaseData will be syncronized across connections:

var ref = new Firebase("https://myURL.firebaseio.com/");                
var sync = $firebase(ref);                                
var firebaseData = sync.$asObject();

您可以查看是否对对象进行了任何更改:

You can watch to see if any changes have been made to the object:

firebaseData.$watch(function(event){
    console.log("Change made to this firebase object");
    // Then you can call a function which could restructure your data:
    restructureData(firebaseData, event);
});

因此您的 restructureData 函数可能如下所示:

So your restructureData function could look like this:

var restructureData = function(firebaseObj, event){
    // This function updates firebase on every change to firebase
    // But we don't want to update it again after running this function
    if(event.key === "changesMadeToFirebase") return;
    firebaseObj.changesMadeToFirebase += 1;
    firebaseObj.$save().then(function(){
        console.log("data restructured");
    }, function(err){
        console.log("There was an error:", err);
    });
};

这允许您检查对 firebase 进行了多少更改，但对字段 "changesMadeToFirebase"

This allows you to check how many changes have been made to firebase, except for the changes to the field "changesMadeToFirebase"

虽然这是一个很小的例子，但您可以在这里找到更多:

Although this is a very small example, you will be able to find much more here:

https://www.firebase.com/docs/web/图书馆/angular/api.html

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