I have some code to check amount of products in WooCommerce is divisible by 6 - however even though a notice is displayed the customer can still checkout with incorrect quantities.
How can I disable WooCommerce 'Place Order' checkout if the condition is not met?
// check that cart items quantities totals are in multiples of 6
add_action( 'woocommerce_check_cart_items', 'woocommerce_check_cart_quantities' );
function woocommerce_check_cart_quantities() {
global $woocommerce;
$multiples = 6;
$total_products = 0;
foreach ( $woocommerce->cart->get_cart() as $cart_item_key => $values ) {
$total_products += $values['quantity'];
}
if ( ( $total_products % $multiples ) > 0 )
wc_add_notice( sprintf( __('You need to buy in quantities of %s products', 'woocommerce'), $multiples ) );
}