Question

Is it possible to catch the HTTP errors (like 404, 500, 504 etc) when we call an external webservice by specifying an absolute url?. (like setting the url: attribute of $.ajax call to have a url value as http://api.geonames.org/findNearbyPostalCodes.

Right now I’m unable to receive any errors although firebug is catching them and showing it in the console.

Can someone help?

Here is my code.

$.ajax({
    type: 'GET',
    url: "http://api.geonames.org/findNearbyPostalCodes",
    data: '{"lat":47,"lng":"9","username":"demo"}',
    dataType: 'json',
    cache:false,
    async:false,
    statusCode:{
        404: function(){
            alert('Page not found');
        },
        500: function(){
            alert('Page not found');
        },
        504: function(){
            alert('Unknown host');
        }
    },
    success: function(data){
    alert(data);
         }
              error: function (xhr, exception, thrownError)
              {
                  alert(xhr.status);
              }
});

Answer 1

No, it is not possible with cross-domain (external) requests using only client-side code. This is because cross-domain requests rely on JSONP – ie, injecting a script tag that loads code from an external source. Unfortunately, the <script> element does not have anything like an onerror event.

You can handle errors with same-domain requests because these typically use XMLHttpRequest, which returns a lot of useful information like status codes and response headers.

Your best bet would be to use your local server as a proxy.