angularjs - 为什么 Angular $http 提供 headersGetter 而不仅仅是 headers？

Question

当使用 $http 时，回调函数是通过 headers getter 调用的。这通常会产生以下代码:

$http.get('example.json').success(function(data, status, headersGetter, config) {
  var headers = headersGetter();
  // Do stuff
});

为什么将 headersGetter 传递给回调而不是仅将 header 作为对象传递？

Answer 1

Why is a headersGetter passed to the callback instead of just the headers as an object?

文档中对此进行了如下解释:

A getter is a function that returns a representation of the model. It's sometimes useful to use this for models that have an internal representation that's different from what the model exposes to the view.

特定于 headersGetter，作为一个函数有助于实现以下目的:

This allows either getting the entire headers object passed in the config, or a specific header value by name (case insensitive).

引用文献

• AngularJS $http API compatibility?