Question

Perform cross domain query, how to perform a certain function if the URL on which it is running is not available (404)?
I try something like this:

$.getJSON({
url:'example.php?callback=?',
statusCode: {
404:function(){alert('404');}
},
success :function(data){//do stuff}
});

Answer 1

Matt posted a great answer in this question that may solve your issue.

You will have to add a success property on your JSON object

var success = false;

$.getJSON(url, function(json) {
    success = true;
    // ... do what you need to do here
});

// Set a 5-second (or however long you want) timeout to check for errors
setTimeout(function() {
    if (!success)
    {
        // Handle error accordingly
        alert("Yup, 404"); // string was "Houston, we have a problem."
    }
}, 5000);

KeYan makes a good suggestion by checking the XHR status property if you aren’t expecting timeout issues. I would vote his solution up, but I lack the rep points.