Hello,
The only way is to code it. I assume you are using shipvalue which comes with Virtuemart 1.1.x? Since you provided ftp access, I have added some code that should do what you want.
in www/administrator/components/com_virtuemart/classes/shipping/shipvalue.php, around line 35 is this:
<?php
if ( $_SESSION['auth']['show_price_including_tax'] != 1 ) {
$taxrate = 1;
$order_total = $total + $tax_total;
}
else {
$taxrate = $this->get_tax_rate() + 1;
$order_total = $total;
}
?>
Right after that, I added this:
<?php
{ # seyi_code
$jdb = JFactory::getDBO();
$jdb->setQuery('SELECT product_id FROM #__awocoupon_giftcert_product WHERE published=1');
$giftcert_product_ids = $db->loadObjectList('product_id');
require_once(CLASSPATH. 'ps_product.php' );
$ps_product = new ps_product;
require_once(CLASSPATH . 'ps_shipping_method.php' );
$cart = $_SESSION['cart'];
for($i = 0; $i < $cart['idx']; $i++) {
if(!isset($giftcert_product_ids[$cart[$i]['product_id']])) continue;
{ # get price
$my_taxrate = $ps_product->get_product_taxrate($cart[$i]["product_id"], ps_shipping_method::get_weight($cart[$i]["product_id"]) * $cart[$i]['quantity']);
$price = $ps_product->get_adjusted_attribute_price($cart[$i]["product_id"], $cart[$i]["description"]);
$price["product_price"] = $GLOBALS['CURRENCY']->convert( $price["product_price"], $price["product_currency"] );
$product_price = $price["product_price"];
if( $auth["show_price_including_tax"] == 1 ) $product_price *= ($my_taxrate+1);
$product_price = round( $product_price, 2 );
$subtotal = $product_price * $cart[$i]["quantity"];
}
$order_total -= $subtotal; // subtract it from the order total
}
}
?>
