jQuery ajax (jsonp) ignores a timeout and doesn't fire the error event

Question

To add some basic error handling, I wanted to rewrite a piece of code that used jQuery's $.getJSON to pull in some photo's from Flickr. The reason for doing this is that $.getJSON doesn't provide error handling or work with timeouts.

Since $.getJSON is just a wrapper around $.ajax I decided to rewrite the thing and surprise surprise, it works flawlessly.

Now the fun starts though. When I deliberately cause a 404 (by changing the URL) or cause the network to timeout (by not being hooked up to the interwebs), the error event doesn't fire, at all. I'm at a loss as to what I'm doing wrong. Help is much appreciated.

Here's the code:

$(document).ready(function(){

    // var jsonFeed = "http://api.flickr.com/services/feeds/photos_public.gne"; // correct URL
    var jsonFeed = "http://api.flickr.com/services/feeds/photos_public.gne_______"; // this should throw a 404

    $.ajax({
        url: jsonFeed,
        data: { "lang" : "en-us",
                "format" : "json",
                "tags" : "sunset"
        },
        dataType: "jsonp",
        jsonp: "jsoncallback",
        timeout: 5000,
        success: function(data, status){
            $.each(data.items, function(i,item){
                $("<img>").attr("src", (item.media.m).replace("_m.","_s."))
                          .attr("alt", item.title)
                          .appendTo("ul#flickr")
                          .wrap("<li><a href=\"" + item.link + "\"></a></li>");
                if (i == 9) return false;
            });
        },
        error: function(XHR, textStatus, errorThrown){
            alert("ERREUR: " + textStatus);
            alert("ERREUR: " + errorThrown);
        }
    });

});

I'd like to add that this question was asked when jQuery was at version 1.4.2

Answer 1

jQuery 1.5 and higher have better support for error handling with JSONP requests. However, you need to use the $.ajax method instead of $.getJSON. For me, this works:

var req = $.ajax({
    url : url,
    dataType : "jsonp",
    timeout : 10000
});

req.success(function() {
    console.log('Yes! Success!');
});

req.error(function() {
    console.log('Oh noes!');
});

The timeout seems to do the trick and call the error handler, when there is no successful request after 10 seconds.

I did a little blogpost on this subject as well.