AngularJS not detecting Access-Control-Allow-Origin header?

There's a workaround for those who want to use Chrome. This extension allows you to request any site with AJAX from any source, since it adds 'Access-Control-Allow-Origin: *' header to the response.

As an alternative, you can add this argument to your Chrome launcher: --disable-web-security. Note that I'd only use this for development purposes, not for normal "web surfing". For reference see Run Chromium with Flags.

As a final note, by installing the extension mentioned on the first paragraph, you can easily enable/disable CORS.

I was sending requests from angularjs using $http service to bottle running on http://localhost:8090/ and I had to apply CORS otherwise I got request errors like "No 'Access-Control-Allow-Origin' header is present on the requested resource"

from bottle import hook, route, run, request, abort, response

#https://github.com/defnull/bottle/blob/master/docs/recipes.rst#using-the-hooks-plugin

@hook('after_request')
def enable_cors():
    response.headers['Access-Control-Allow-Origin'] = '*'
    response.headers['Access-Control-Allow-Methods'] = 'POST, GET, OPTIONS, PUT'
    response.headers['Access-Control-Allow-Headers'] = 'Origin, X-Requested-With, Content-Type, Accept'

I experienced this exact same issue. For me, the OPTIONS request would go through, but the POST request would say "aborted." This led me to believe that the browser was never making the POST request at all. Chrome said something like "Caution provisional headers are shown" in the request headers but no response headers were shown. In the end I turned to debugging on Firefox which led me to find out my server was responding with an error and no CORS headers were present on the response. Chrome was actually receiving the response, but not allowing the response to be shown in the network view.

CROS needs to be resolved from server side.

Create Filters as per requirement to allow access and add filters in web.xml

Example using spring:

Filter Class:

@Component
public class SimpleFilter implements Filter {

@Override
public void init(FilterConfig arg0) throws ServletException {}

@Override
public void doFilter(ServletRequest req, ServletResponse resp,
                     FilterChain chain) throws IOException, ServletException {

    HttpServletResponse response=(HttpServletResponse) resp;

    response.setHeader("Access-Control-Allow-Origin", "*");
    response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
    response.setHeader("Access-Control-Max-Age", "3600");
    response.setHeader("Access-Control-Allow-Headers", "x-requested-with");

    chain.doFilter(req, resp);
}

@Override
public void destroy() {}

}

Web.xml:

<filter>
    <filter-name>simpleCORSFilter</filter-name>
    <filter-class>
        com.abc.web.controller.general.SimpleFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>simpleCORSFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

I just ran into this problem today. It turned out that a bug on the server (null pointer exception) was causing it to fail in creating a response, yet it still generated an HTTP status code of 200. Because of the 200 status code, Chrome expected a valid response. The first thing that Chrome did was to look for the 'Access-Control-Allow-Origin' header, which it did not find. Chrome then cancelled the request, and Angular gave me an error. The bug during processing the POST request is the reason why the OPTIONS would succeed, but the POST would fail.

In short, if you see this error, it may be that your server didn't return any headers at all in response to the POST request.

It can also happen when your parameters are wrong in the request. In my case I was working with a API that sent me the message

"No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access. The response had HTTP status code 401."

when I send wrong username or password with the POST request to login.

Instead of using $http.get('abc/xyz/getSomething') try to use $http.jsonp('abc/xyz/getSomething')

     return{
            getList:function(){
                return $http.jsonp('http://localhost:8080/getNames');
            }
        }

If you guys are having this problem in sails.js just set your cors.js to include Authorization as the allowed header

/***************************************************************************
  *                                                                          *
  * Which headers should be allowed for CORS requests? This is only used in  *
  * response to preflight requests.                                          *
  *                                                                          *
  ***************************************************************************/

  headers: 'Authorization' // this line here