javascript - 无法访问返回的 JSON 对象的子对象

Question

我可能只是盲目的或者什么的，但我真的不明白为什么我无法访问返回的 $Resource 对象的子对象，该对象检索了一堆 JSON 对象。

Resource
> $resolved: true
> $then: function (b, g) {var j=e(),h=
> data: Object
  > 519bc5f6b2427a732be1c360: Object

原始 JSON 如下所示:

{
    "data": {
        "519bc5f6b2427a732be1c360": {
            "id": "519bc5f6b2427a732be1c360",
            "planning": {
                "id": "519bc5f6b2427a732be1c355"
            }
        }
    }
}

谁能解释一下为什么这不起作用:

var training = Training.query()

console.log(training); // returns the entire $Resource
console.log(training.data); // returns: undefined 

Answer 1

这里是解释 - 来自 the Angular docs :

It is important to realize that invoking a $resource object method immediately returns an empty reference (object or array depending on isArray). Once the data is returned from the server the existing reference is populated with the actual data. This is a useful trick since usually the resource is assigned to a model which is then rendered by the view. Having an empty object results in no rendering, once the data arrives from the server then the object is populated with the data and the view automatically re-renders itself showing the new data. This means that in most case one never has to write a callback function for the action methods.

所以这有效:

var training = Training.query(function(value){
  // this is the callback function
  console.log(training === value); // true - it's the same object
  console.log(training.data); // and now it has data
});