This is to stop WordPress in handling 404, using headers to manage cache expiry. This code should be added to the theme’s functions.php file.
function template_slug_404_cache() {
if( is_404() ){
header( 'Cache-Control: max-age=30000, must-revalidate' );
header( 'Expires: ' . date( 'D, d M Y H:i:s', strtotime( '+5000 minutes' ) ) . 'UTC' );
header( 'Last-Modified: ' . date( 'D, d M Y H:i:s', strtotime( '-5000 minutes' ) ) . 'UTC' );
}
}
/**
* Redirect a 404 to a cache page
*
* @return void
*/
function template_slug_404_redirect() {
if ( is_404() ) {
header( 'Location:' . site_url( '/404' ) );
exit();
}
}
add_action( 'template_redirect', 'template_slug_404_cache' );
Be sure that there is a 404.php file on the template directory.
