Add custom field (ACF) to WooCommerce completed order email notification - wordpress

Question

There are many threads which deal with the topic "custom fields in WooCommerce emails" but I couldn't find the exact case I am struggling with.
I could achieve 50% of this project to display the field as a meta in the order table.
add_action( 'woocommerce_order_item_meta_end', 'custom_product_info', 20, 4 );
function custom_product_info ( $item_id, $item, $order, $plain_text ) {
$id = $item->get_product_id();
$erlebnisidgc = get_field('erlebnis_id',$id);
if($erlebnisidgc){
echo "<p>Here's your Link</p><a href=https://b-ceed.de/?eventid='.$erlebnisidgc'>Testlink</a>";
}
}
So this code works perfectly with the custom field. Problem is that this output isn't shown only in the customer_completed_order email but also in all other emails.
Therefore, I tried this code snippet:
add_action( 'woocommerce_order_item_meta_end', 'custom_product_info', 20, 4 );
function custom_product_info ( $item_id, $item, $order, $plain_text ) {
if ( $email->id == 'customer_completed_order' ) {
$id = $item->get_product_id();
$erlebnisidgc = get_field('erlebnis_id',$id);
if($erlebnisidgc){
echo "<p>Here's your Link</p><a href=https://b-ceed.de/?eventid='.$erlebnisidgc'>Testlink</a>";
}
}
}
But now the output won't be displayed in any email anymore and it triggers a internal server error. Any advice?

Answer 1

$email ($email->id) is not passed as argument to the woocommerce_order_item_meta_end hook, therefore it is undefined
So to target specific email notifications a workaround will be needed, this can be done by creating a global variable via the woocommerce_email_before_order_table hook
So you get:
// Setting global variable
function action_woocommerce_email_before_order_table( $order, $sent_to_admin, $plain_text, $email ) {
$GLOBALS['email_data'] = array(
'email_id' => $email->id, // The email ID (to target specific email notification)
'is_email' => true // When it concerns a WooCommerce email notification
);
}
add_action( 'woocommerce_email_before_order_table', 'action_woocommerce_email_before_order_table', 1, 4 );
function action_woocommerce_order_item_meta_end( $item_id, $item, $order, $plain_text ) {
// Getting the custom 'email_data' global variable
$ref_name_globals_var = $GLOBALS;
// Isset & NOT empty
if ( isset ( $ref_name_globals_var ) && ! empty( $ref_name_globals_var ) ) {
// Isset
$email_data = isset( $ref_name_globals_var['email_data'] ) ? $ref_name_globals_var['email_data'] : '';
// NOT empty
if ( ! empty( $email_data ) ) {
// Target specific emails, several can be added in the array, separated by a comma
$target_emails = array( 'customer_completed_order' );
// Target specific WooCommerce email notifications
if ( in_array( $email_data['email_id'], $target_emails ) ) {
// Get product ID
$product_id = $item->get_product_id();
// Get field
$erlebnisidgc = get_field( 'erlebnis_id', $product_id );
// Has some value
if ( $erlebnisidgc ) {
echo '<p>Here is your Link</p>';
echo 'Testlink';
}
}
}
}
}
add_action( 'woocommerce_order_item_meta_end', 'action_woocommerce_order_item_meta_end', 10, 4 );
Used in this answer:
Determine only for WooCommerce admin email notification
How to target other WooCommerce order emails