The ms_site_not_found WordPress PHP action fires when a network can be determined but a site cannot. At the time of this action, the only recourse is to redirect somewhere and exit. If you want to declare a particular site, do so earlier.
Usage
add_action('ms_site_not_found', 'your_custom_function', 10, 3);
function your_custom_function($current_site, $domain, $path) {
// Your custom code here
}
Parameters
$current_site(WP_Network): The network that had been determined.$domain(string): The domain used to search for a site.$path(string): The path used to search for a site.
More information
See WordPress Developer Resources: ms_site_not_found
Examples
Redirect to a custom 404 page
Redirect users to a custom 404 page when a site is not found.
add_action('ms_site_not_found', 'redirect_to_custom_404', 10, 3);
function redirect_to_custom_404($current_site, $domain, $path) {
wp_redirect('/custom-404-page/');
exit;
}
Redirect to the main site
Redirect users to the main site when a site is not found.
add_action('ms_site_not_found', 'redirect_to_main_site', 10, 3);
function redirect_to_main_site($current_site, $domain, $path) {
wp_redirect($current_site->domain);
exit;
}
Log site not found errors
Log site not found errors for further investigation.
add_action('ms_site_not_found', 'log_site_not_found', 10, 3);
function log_site_not_found($current_site, $domain, $path) {
error_log("Site not found: domain - {$domain}, path - {$path}");
}
Redirect to a search page
Redirect users to a search page with the domain as the search query.
add_action('ms_site_not_found', 'redirect_to_search', 10, 3);
function redirect_to_search($current_site, $domain, $path) {
wp_redirect('/search/?q=' . urlencode($domain));
exit;
}
Display a custom error message
Display a custom error message when a site is not found.
add_action('ms_site_not_found', 'display_custom_error_message', 10, 3);
function display_custom_error_message($current_site, $domain, $path) {
wp_die('The site you are looking for could not be found.', 'Site Not Found', array('response' => 404));
}