How can I style the WordPress failure notice page? - css

Question

Is there a way I can style the WordPress failure notice page? Take a look at the screenshot below which shows an example of the page. This page is generated at various times and for various reasons. To generate the page, open 2 tabs in your browser and login to the same WordPress site on each tab.
1: log out of the site via the first tab you have open.
2: log out via the second tab.
You'll see the failure page.

Answer 1

The approach I took was to set up a custom die handler which gives you the option to style all 'die' messages.
// custom die handler
function get_custom_die_handler() {
return 'custom_die_handler';
}
// hook the function
add_filter('wp_die_handler', 'get_custom_die_handler' );
// build a custom die handler
function custom_die_handler( $message, $title = '', $args = array() ) {
// whatever you want the die handler to do
}

Answer 2

Navigate to the file /wp-includes/functions.php look for a function called
wp_nonce_ays
That is the function which outputs the error page. That is a core function, which is called by the action of check_admin_referer. You could try to hook into that action; the only problem is that it dies after wp_nonce_ays is called, so using add_action has no effect since it dies before it would trigger. However, luckily, check_admin_referer is a pluggable function, so you can make a function to override it. Our function will be an exact copy of check_admin_referer except one extra line of code is added to style it. Save the function, I called it styleFailPage.php, and put it in your /wp-content/plugins/ folder.
<?php /*
* Plugin Name:Failure Styler
* Description:Adds a style element right before the failure notice is called
*/
if ( ! function_exists( 'wp_logout' ) ) {
function check_admin_referer($action = -1, $query_arg = '_wpnonce') {
if ( -1 == $action )
_doing_it_wrong( __FUNCTION__, __( 'You should specify a nonce action to be verified by using the first parameter.' ), '3.2' );
$adminurl = strtolower(admin_url());
$referer = strtolower(wp_get_referer());
$result = isset($_REQUEST[$query_arg]) ? wp_verify_nonce($_REQUEST[$query_arg], $action) : false;
if ( !$result && !(-1 == $action && strpos($referer, $adminurl) === 0) ) {
//this is the line I added:
echo "<style>body {background:red !important;}</style>";
wp_nonce_ays($action);
die();
}
do_action('check_admin_referer', $action, $result);
return $result;
}
}
?>
This will make invalid HTML because you have to end up inserting the <style> info ABOVE the doctype declaration, however AFAIK this is unavoidable without explicitly editing the core wp_nonce_ays function