如何加载角formly vm.fields从远程生成的JSON对象？ [英] How to load angular-formly vm.fields object from remotely-generated json?

问题描述

在我的应用我有什么，否则相同形式的动态字段设置。我可以从服务器加载它们，如JavaScript包括和工程确定。

In my application I have dynamic field sets on what is otherwise the same form. I can load them from the server as javascript includes and that works OK.

然而，这将是更好的，以便能够从一个单独的API加载它们。

However, it would be much better to be able to load them from a separate API.

$。的getJSON（）提供加载JSON的好办法，但我还没有找到合适的地方来做到这一点。显然，它需要编译步骤开始之前完成。

$.getJSON() provides a good way to load the json but I have not found the right place to do this. Clearly it needs to be completed before the compile step begins.

我看到有一个fieldTransform设施的formly。难道这是用来无论从API进来，从一个空对象变换vm.fields？

I see there is a fieldTransform facility in formly. Could this be used to transform vm.fields from an empty object to whatever comes in from the API?

如果这样我会怎么做呢？

If so how would I do that?

THX。保罗

推荐答案

THX @kent

Thx @kent

好了，我们需要更换getFields（）与此承诺

OK, so we need to replace the getFields() promise with this

function getFields() {
  return $http.get('fields-demo.json', {headers:{'Cache-Control':'no-cache'}});
}       

这所以vm.loadingData我们说返回data.fields

This returns data.fields so in vm.loadingData we say

vm.fields = result[0].data;

似乎就OK了为我工作。

Seems to work for OK for me.

在测试我注意到，你必须确保有什么不对您的JSON如使用还没有定义一个字段类型。在这种情况下所产生的错误信息不是很清楚。

When testing I noticed that you have to make sure there is nothing wrong with your json such as using a field type you haven't defined. In that case the resulting error message is not very clear.

此外，你需要处理其中的数据源不可用的情况。我想这样的：

Furthermore you need to deal with the situation where the source of the data is unavailable. I tried this:

function getFields() {
  console.log('getting',fields_url);
    return $http.get(fields_url, {headers: {'Cache-Control':'no-cache'}}).
    error(function() {
      alert("can't get fields from server");
      //return new Promise({status:'fields server access error'}); //??
    });

..这也至少抛出警报。但是，我不知道如何更换的承诺，从而错误传播给调用者。

.. which does at least throw the alert. However, I'm not sure how to replace the promise so as to propagate the error back to the caller.

保

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