Filter out unwanted order item meta data from Woocommerce email notifications

Question

In the order email templates (for example email-order-items.php), WooCommerce uses the function wc_display_item_meta to display product details in

Answer 1

There is a bug with the accepted answer, and all of the other snippets that I've found around the internet, so I'm posting my own answer here in the hopes that stores around the world don't accidentally leak information.

The problem is that when you use the Order actions meta box to resend the email, the filter check fails because is_admin() === true.

The order actions is a meta box down the side of the Orders page:

So the first time, when the order is created, it filters the email like you want, but then if an admin resends the email to a customer then it will be broken and show all of the meta fields to the user in the resent email.

The code that fixes this scenario is this:

$is_resend = isset($_POST['wc_order_action']) ?  wc_clean( wp_unslash( $_POST['wc_order_action'] ) ) === 'send_order_details' : false;

if ( !$is_resend && (is_admin() || is_wc_endpoint_url() ) ) {
  return $formatted_meta;
}

So if you look at the linked snippet then you will see the meta box adds that field to the $_POST. It has to be cleaned up like that as well or it won't match.

The full example integrated into the accepted solution's answer is:

add_filter( 'woocommerce_order_item_get_formatted_meta_data', 'unset_specific_order_item_meta_data', 10, 2);

function unset_specific_order_item_meta_data($formatted_meta, $item){
    // Only on emails notifications
    $is_resend = isset($_POST['wc_order_action']) ?  wc_clean( wp_unslash( $_POST['wc_order_action'] ) ) === 'send_order_details' : false;

    if ( !$is_resend && (is_admin() || is_wc_endpoint_url() ) ) {
      return $formatted_meta;
    }

    foreach( $formatted_meta as $key => $meta ){
        if( in_array( $meta->key, array('Qty Selector', 'Qty', 'Total') ) )
            unset($formatted_meta[$key]);
    }
    return $formatted_meta;
}