Code-Snippets-Functions/Execute a function on a child site/WooCommerce/prevent-access-to-checkout-without-shipping-method.txt

add_action( 'woocommerce_check_cart_items', 'required_chosen_shipping_methods' );
function required_chosen_shipping_methods() {
    $chosen_shipping_methods = WC()->session->get( 'chosen_shipping_methods' );

    if( is_array( $chosen_shipping_methods ) && count( $chosen_shipping_methods ) > 0 ) {
        // Display an error message
        wc_add_notice( __("A shipping method is required in order to proceed to checkout."), 'error' );
    }
}