no problem, I just wanted to keep it simple for you. Here’s a more complete, internationalized example to build from:
add_filter( 'wpo_wcpdf_filename', 'wpo_wcpdf_custom_filename', 10, 4 );
function wpo_wcpdf_custom_filename( $filename, $template_type, $order_ids, $context ) {
global $wpo_wcpdf;
$count = count($order_ids);
switch ($template_type) {
case 'invoice':
$name = _n( 'invoice', 'invoices', $count, 'wpo_wcpdf' );
$number = $wpo_wcpdf->export->get_display_number( $order_ids[0] );
break;
case 'packing-slip':
$name = _n( 'packing-slip', 'packing-slips', $count, 'wpo_wcpdf' );
$number = $wpo_wcpdf->export->order->get_order_number();
break;
default:
$name = $template_type;
$number = $wpo_wcpdf->export->order->get_order_number();
break;
}
if ( $count == 1 ) {
$suffix = $number;
} else {
$suffix = date('Y-m-d'); // 2020-11-11
}
$filename = $name . '-' . $suffix . '.pdf';
return $filename;
}