Save order meta when using the "woocommerce_new_order" hook - wordpress

Question

I need to trace if a product is bought from a user coming from a specific site, that's why I need to set a meta for the order.
Let's focus on this piece of my code:
add_action( 'woocommerce_new_order', 'add_affilate_meta', 10, 1);
function add_affilate_meta( $order_id ){
$targetProd = 3115;
// check if product is present
$order = wc_get_order( $order_id );
$affiliationProduct = false;
foreach ($order->get_items() as $item_key => $item ):
$product_id = $item->get_product_id();
if($product_id == $targetProd):
$affiliationProduct = true;
break;
endif;
endforeach;
// this is just for debug
update_post_meta( $order_id, 'test_affiliate', $product_id );
... some other stuff ...
}
$affiliationProduct and, consequently, test_affiliate meta are always false/empty. Why? I'm sure, of course, that the article is present in the order. It seems like the order is not "ready" when I try to analyze it's content.
I cannot find any other way to debug the code, because I cannot var_dump() nothing without causing JSON errors.
Any help will be appreciated.

Answer 1

You can indeed use the woocommerce_new_order hook, but what is missing in your code is $order->save();
So you get:
function action_woocommerce_new_order( $order_id ) {
// Get the WC_Order Object
$order = wc_get_order( $order_id );
// Setting
$target_prod = 30;
// Initialize
$affiliation_product = false;
$product_id = 0;
// Loop trough
foreach ( $order->get_items() as $item_key => $item ) {
// Get
$product_id = $item->get_product_id();
// Compare
if ( $product_id == $target_prod ) {
$affiliation_product = true;
break;
}
}
// Update meta data
$order->update_meta_data( 'test_affiliate', $product_id );
// Save
$order->save();
// When true
if ( $affiliation_product ) {
// Do something
}
}
add_action( 'woocommerce_new_order', 'action_woocommerce_new_order', 10, 1 );