template redirect woocommerce display notice example

1// redirect empty checkouts and completed orders.
2add_action( 'template_redirect', 'myfunction' );
3function myfunction() {
4
5    if( is_wc_endpoint_url( 'order-received' ) && isset( $_GET['key'] ) ) {
6        wp_redirect('www.myurl.com'); // go to custom page if order has been received
7        exit;
8    }
9
10    if ( is_checkout() && 0 == WC()->cart->get_cart_contents_count() ) {
11       wp_safe_redirect( home_url() ); // if trying to access checkout with empty cart go back
12       exit;
13    }  
14}