Add WC Order Attribution data when processing Express Payment button requests

[james-allan]

Fixes #3022

Changes proposed in this Pull Request:

When a store has Order Attribution data enabled, payments via express payment buttons (Apple Pay, Google Pay etc) were missing this order attribution data.

This PR fixes that by:

1. Including a <wc-order-attribution-inputs></wc-order-attribution-inputs> element where ever we include the express payment button.
   • This element will be automatically populated by WC core with the attribution data so we can stay at an arms length from the implementation layer.
2. When we submit the AJAX request to process the express payment button, we submit whatever input elements were populated.
   • WC core will then pull the required fields out of the request and handle the attribution.

Testing instructions

1. Enable Order attribution in WooCommerce → Settings → Advanced → Features

2. Set up Stripe and enable Express Payment buttons. ⚠️ Remember you may need to add your domain to your stripe settings. See this doc: https://woocommerce.com/document/stripe/setup-and-configuration/express-checkouts/#apple-pay-requirements
3. Purchase a product using Google Pay or Apple Pay.
4. View the order in your admin dashboard and notice that there is no order attribution data.

5. Checkout this branch (fix/3022-order-attribution-express-buttons).
6. Purchase a product using Apple Pay or Google Pay again.
7. View the order in the dashboard. This time it should have attribution data.

---

• Covered with tests (or have a good reason not to test in description ☝️)
• Added changelog entry in both changelog.txt and readme.txt (or does not apply)
• Tested on mobile (or does not apply)

Post merge

• Added testing instructions to the Release Testing Instructions wiki page (or does not apply)

[Mayisha]

Hi @james-allan 👋
Thanks for working on this.

The fix is working for shortcode cart and checkout, order attribution data is set properly.
But order attribution data is not set and still showing Unknown when I purchase from block cart or block checkout. I have used Google Pay for testing.

In the screenshot below, the second order is placed from shortcode checkout which has the origin Direct and the first order with origin Unknown is placed from block checkout.

I think we need to make similar changes in https://github.com/woocommerce/woocommerce-gateway-stripe/blob/fix/3022-order-attribution-express-buttons/client/api/blocks.js#L68 to add the attribution data when using block cart/checkout.

[james-allan]

The fix is working for shortcode cart and checkout, order attribution data is set properly.
But order attribution data is not set and still showing Unknown when I purchase from block cart or block checkout.

Good callout @Mayisha. I've tried to get the block checkout and cart to correctly include order attribution data, however, I'm not sure how to get WC core to either populate the <wc-order-attribution-inputs> elements. I've asked the WC Core folks if they are aware of ways to fix it in this block context. You can find that comment here: woocommerce/woocommerce#46309 (comment)

I'm going to put this one on hold for now until we can resolve that.