Form that makes browser redirect when accessed by either a regular form submit or an Ajax request - is this possible?

Question

I have a web page with a form. When the user submits the form, I want the server to make the browser redirect to a different page from the form action. Right now, I am doing

Answer 1

HTTP 302 response are consumed silently by XmlHttpRequest implementations (e.g. jQuery's ajax function). It's a feature.

The way I've solved this in the past is to detect for XmlHttpRequests and issue a "Content-Location" header (rather than a "Location" header). The most cross-library way of doing this is to check for the "X-Requested-With" http header in your server-side code (jQuery, Prototype, Mootools among others set this):

if (@$_SERVER['HTTP_X_REQUESTED_WITH']  == 'XMLHttpRequest') {
    header('Content-Location: ' . $redirect_url);
} else {
    header('Location: ' . $redirect_url);
}

You still need to special-case your client-side code:

$.ajax({
    // ...
    complete: function(xhr) {
        var redirect_url = xhr.getResponseHeader("Content-Location");
        if (redirect_url) {
            window.location = redirect_url;
        }
    }
})