How do I add the GA4 ecommerce dataLayer to WooCommerce? - e-commerce

Question

I am busy with implementing the GA4 ecommerce dataLayer in my WooCommerce site. There are a few plug-ins which can implement the dataLayer for Universal Analytics (e.g. this one, for $99 per year), but I can't find anything for GA4.
This is the dataLayer for the purchase event (source):
dataLayer.push({
'event': 'purchase',
'ecommerce': {
'purchase': {
'transaction_id': 'T12345',
'affiliation': 'Online Store',
'value': '35.43',
'tax': '4.90',
'shipping': '5.99',
'currency': 'EUR',
'coupon': 'SUMMER_SALE',
'items': [{
'item_name': 'Triblend Android T-Shirt',
'item_id': '12345',
'item_price': '15.25',
'item_brand': 'Google',
'item_category': 'Apparel',
'item_variant': 'Gray',
'quantity': 1,
'item_coupon': ''
}, {
'item_name': 'Donut Friday Scented T-Shirt',
'item_id': '67890',
'item_price': '33.75',
'item_brand': 'Google',
'item_category': 'Apparel',
'item_variant': 'Black',
'quantity': 1
}]
}
}
});
Can anyone help me out to put the variables in it?

Answer 1

Found it already i guess:
<script type='text/javascript'>
window.dataLayer = window.dataLayer || [];
dataLayer.push({
'event': 'purchase',
'ecommerce': {
'purchase': {
'transaction_id': '<?php echo $order->get_order_number(); ?>',
'affiliation': '<?php echo get_option("blogname"); ?>',
'value': '<?php echo number_format($order->get_subtotal(), 2, ".", ""); ?>',
'tax': '<?php echo number_format($order->get_total_tax(), 2 ,".", ""); ?>',
'shipping': '<?php echo number_format($order->calculate_shipping(), 2 , ".", ""); ?>',
'currency': 'EUR',
<?php if($order->get_used_coupons()) : ?>
'coupon': '<?php echo implode("-", $order->get_used_coupons()); ?>',
<?php endif; ?>
'items': [
<?php
foreach ( $order->get_items() as $key => $item ) :
$product = $order->get_product_from_item($item);
$variant_name = ($item['variation_id']) ? wc_get_product($item['variation_id']) : '';
?>
{
'item_name': '<?php echo $item['name']; ?>',
'item_id': '<?php echo $item['product_id']; ?>',
'item_price': '<?php echo number_format($order->get_line_subtotal($item), 2, ".", ""); ?>',
'item_brand': '',
'item_category': '<?php echo strip_tags($product->get_categories(', ', '', '')); ?>',
'item_variant': '<?php echo ($variant_name) ? implode("-" , $variant_name->get_variation_attributes()) : ''; ?>',
'quantity': <?php echo $item['qty']; ?>,
'item_coupon': ''
},
<?php endforeach; ?>
]
}
});
</script>

Answer 2

Just in case anyone else needs a WordPress plugin that can integrate WooCommerce with GA4. There is a solution that can do that using Google Tag Manager:
https://wordpress.org/plugins/gtm-ecommerce-woo/
It covers the purchase and add_to_cart events and takes care of populating those values.