Find coupon creator on payment completion in WooCommerce

Question

I'm developing a plugin.

I need to find out when any coupon issued by a specific user_id used in any order on payment completion.

Answer 1

It is possible to retrieve coupons used by an order using get_coupons() method on WC_Order instance:

$coupons = $order->get_coupons();

If you need only coupon codes just call get_coupon_codes(). It returns an array of strings:

$coupon_codes = $order->get_coupon_codes();

Now if you want to check it on order payment you WooCommerce hooks:

add_action( 'woocommerce_payment_complete', 'my_payment_completion_hook' );

function aac_wc_payment_complete_hook( $order_id ) {
    $order        = wc_get_order( $order_id );
    $used_coupons = $order->get_coupon_codes();
    if ( count( $used_coupons ) ) {
        $coupon       = new WC_coupon( $used_coupons[0] );
        $post         = get_post( $coupon->id );
        $user_id = $post->post_author;
        if ( $user_id == 100) {
            // Do some stuff
        }
    }
}