Question

Alright, so I tried to use .htaccess to set up ErrorDocuments for various error codes. It works great, except that now, the following jQuery AJAX code will never run the error() function:

$.ajax({url: url, type: "GET", cache: false, error: function(){
 alert("Looking rather erroneous, are we?");
}, success: function(html){
 // ...
}

Any proposals? I think I know the reason why: .htaccess points all errors like so:

ErrorDocument 404 /error.php

And /error.php has the following:

<?php header("Location: /#error"); ?>

So when it transfers to index.php, it probably loses the 404 document status.

What would you suggest?

Answer 1

Try passing a header along with your AJAX request:

$.ajax({url: url, type: "GET", cache: false, headers: {'X-My-AJAX-Header': 'yes'}, error: function(){
 alert("Looking rather erroneous, are we?");
}, success: function(html){
 // ...
}

…which you can then detect in your error.php, to treat errors from AJAX requests differently:

<?php
if (isset($_SERVER['HTTP_X_MY_AJAX_HEADER'])) {
    header('Status: 404');
} else {
    header("Location: /#error");
}
?>

You may have to experiment with that $_SERVER key. See also apache_request_headers if you’re using Apache/mod_php.

EDIT:

The reason you need to do this is, as stated below, the header("Location: /#error"); sends a 302 (redirect) header, which overrides the 404 (not found). You can’t use the Location: header to redirect on a 404 (it only works on 3xx) and you can only send one status. JQuery will (correctly) only trigger the error callback on an error status; these are all 4xx.

Wikipedia‘s explanation of this is very good.