Fill out custom field with used coupon code WooCommerce

问题

Right now I'm working with a mailchimp plugin that needs a custom field for validating/segmenting.

For this segment I want to check what kind of coupon is used. So I scavenged the following code that should fill my custom field with the used coupons:

add_action( 'woocommerce_checkout_update_order_meta', 
'my_custom_checkout_field_update_order_meta' );

function my_custom_checkout_field_update_order_meta( $order_id ) {
if ( empty( $_POST['my_field_name'] ) ) {
    $coupons = $order->get_used_coupons();
    update_post_meta( $order_id, 'my_field_name', $coupons);
}
}

Sadly this will only crash my site.

Any help would be greatly appreciated.

回答1:

There are several problems with your code:

• You're not validating if the field has any information, so you need to check if $_POST has the my_field_name key
• You need to load the $order variable in order to get the used coupons.
• What happens when there's a my_field_value? Do you store it?

Here's the modified code:

add_action( 'woocommerce_checkout_update_order_meta', 
'my_custom_checkout_field_update_order_meta' );

function my_custom_checkout_field_update_order_meta( $order_id, $posted ) {
  if ( isset($_POST['my_field_name']) && empty( $_POST['my_field_name'])) {
    $order = new WC_Order( $order_id );
    $coupons = $order->get_used_coupons();
    update_post_meta( $order_id, 'my_field_name', $coupons);
  }

}

来源：https://stackoverflow.com/questions/35748925/fill-out-custom-field-with-used-coupon-code-woocommerce