Replace Invoice Number with Order Number in Filename

Hi!
The documentation for creating custom filenames can be found here:
Custom PDF filenames.

By far the easiest way to accomplish this is with the Professional extension because it lets you do this via the plugin settings the {{order_number}} placeholder.

Here’s a filter that uses the order number in the filename:

add_filter( 'wpo_wcpdf_filename', 'wpo_wcpdf_custom_filename',9999, 4 );
function wpo_wcpdf_custom_filename( $filename, $template_type, $order_ids, $context ) {
    if ($template_type == 'invoice' && count($order_ids) == 1 ) {
        $order_id = array_pop( $order_ids );
        $order = wc_get_order( $order_id );
        $order_number = $order->get_order_number();
        $name = _n( 'invoice', 'invoices', 1, 'woocommerce-pdf-invoices-packing-slips' );
        $filename = "{$name}-{$order_number}.pdf";
    }
    return $filename;
}

Hope that helps!

Thanks so much! ??