Joomla 1.5 + VirtueMart 1.1.2 Google Analytics Ecommerce tracking integration

checkout.thankyou.tpl.php

<?php
// components/com_virtuemart/themes/default/templates/pages/checkout.thankyou.tpl.php
// after line 24

$order_id = $db->record[0]->order_id;
$order_items = new ps_DB;
$q  = "SELECT * FROM `#__{vm}_order_item` WHERE `order_id`='$order_id'";
$order_items->query($q);

$GLOBALS['GA_ECOMM_ITEMS'] = array();
foreach ($order_items->record as $item) {
    $GLOBALS['GA_ECOMM_ITEMS'][] = array(
        'sku' => $item->order_item_sku,
        'name' => htmlspecialchars($item->order_item_name),
        'category' => '',
        'price' => $item->product_final_price,
        'quantity' => $item->product_quantity,
    );
}

$GLOBALS['GA_ECOMM_TRANS'] = array(
    'id' => $order_id,
    'affiliation' => '',
    'revenue' => $db->record[0]->order_total,
    'shipping' => $db->record[0]->order_shipping,
    'tax' => $db->record[0]->order_tax
);

index.php

<!-- Put the following before </head> -->
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');

ga('create', 'UA-YOUR_ACCOUNT_ID', 'auto');
ga('require', 'ecommerce');
</script>

<!-- The following should go right before </body> -->    
<script>
<?php
function getItemJs(&$transId, &$item) {
    return "
        ga('ecommerce:addItem', {
            'id': '$transId',
            'name': '{$item['name']}',
            'sku': '{$item['sku']}',
            'category': '{$item['category']}',
            'price': '{$item['price']}',
            'quantity': '{$item['quantity']}'
        });
    ";
}

function getTransactionJs(&$trans) {
    return "
        ga('ecommerce:addTransaction', {
            'id': '{$trans['id']}',
            'affiliation': '{$trans['affiliation']}',
            'revenue': '{$trans['revenue']}',
            'shipping': '{$trans['shipping']}',
            'tax': '{$trans['tax']}'
        });
    ";
}

if (!empty($GLOBALS['GA_ECOMM_TRANS'])) {
    echo getTransactionJs($GLOBALS['GA_ECOMM_TRANS']);

    foreach ($GLOBALS['GA_ECOMM_ITEMS'] as &$item) {
        echo getItemJs($trans['id'], $item);
    }

    echo "ga('ecommerce:send');";
}
?>

ga('send', 'pageview');

</script>