AngularJS performs an OPTIONS HTTP request for a c

Question

I'm trying to setup AngularJS to communicate with a cross-origin resource where the asset host which delivers my template files is on a different domain and therefore the XHR request that angular performs must be cross-domain. I've added the appropriate CORS header to my server for the HTTP request to make this work, but it doesn't seem to work. The problem is that when I inspect the HTTP requests in my browser (chrome) the request sent to the asset file is an OPTIONS request (it should be a GET request).

I'm not sure whether this is a bug in AngularJS or if I need to configure something. From what I understand the XHR wrapper can't make an OPTIONS HTTP request so it looks like the browser is trying to figure out if is "allowed" to download the asset first before it performs the GET request. If this is the case, then do I need to set the CORS header (Access-Control-Allow-Origin: http://asset.host...) with the asset host as well?

Answer 1

The same document says

Unlike simple requests (discussed above), "preflighted" requests first send an HTTP OPTIONS request header to the resource on the other domain, in order to determine whether the actual request is safe to send. Cross-site requests are preflighted like this since they may have implications to user data. In particular, a request is preflighted if:

It uses methods other than GET or POST. Also, if POST is used to send request data with a Content-Type other than application/x-www-form-urlencoded, multipart/form-data, or text/plain, e.g. if the POST request sends an XML payload to the server using application/xml or text/xml, then the request is preflighted.

It sets custom headers in the request (e.g. the request uses a header such as X-PINGOTHER)

When the original request is Get with no custom headers, the browser should not make Options request which it does now. The problem is it generates a header X-Requested-With which forces the Options request. See https://github.com/angular/angular.js/pull/1454 on how to remove this header