Avoid checkout for mixed backorder and normal items in Woocommerce

Question

Is it possible to disable checkout if there is backorder item mixed with in stock items. The code so far is displaying message if there is mixed items in the cart, but they

Answer 1

What about this?

...
if ( es_check_cart_has_backorder_product() ) {
       add_filter('woocommerce_order_button_html', 'sg_remove_payment_button');
}
...


function sg_remove_payment_button ($button){


        $output = '
';
        $output .= 'Sorry, you cannot complete this order';
        $output .= '
';


        $output .= '';

    return $output;
}