template_redirect woocommerce display notice example
// redirect empty checkouts and completed orders.
add_action( 'template_redirect', 'myfunction' );
function myfunction() {
if( is_wc_endpoint_url( 'order-received' ) && isset( $_GET['key'] ) ) {
wp_redirect('www.myurl.com'); // go to custom page if order has been received
exit;
}
if ( is_checkout() && 0 == WC()->cart->get_cart_contents_count() ) {
wp_safe_redirect( home_url() ); // if trying to access checkout with empty cart go back
exit;
}
}