Prevent tracking admins or order multiple times and additional adjustments

[martynmjones]

Changes proposed in this Pull Request:

Following on from #322, this PR ensures that no tracking happens if disable_tracking() returns true. Additionally, the new tracking wasn't considering the _ga_tracked meta value for orders meaning if a user was to refresh the thank you page multiple purchase events would be triggered which is fixed in 94b4dc7.

Additional cleanup:

• Removed async_script_loader_tags() and set strategy on the enqueued script 4e8e1ac
• Added filter to adjust gtag config
• Added check to confirm specific event is enabled before tracking d7befb1 (This was added earlier but lost in a previous PR)
• Removed settings that are no longer relevant with GA4 3b26491
  1. Enable Standard Tracking
     • Previously had an impact on how things were loaded but didn't do much beyond that. The option description did not seem to be particularly relevant either so I thought the best option was to remove it entirely
  2. Use Enhanced Link Attribution
     • No longer relevant. See https://developers.google.com/analytics/devguides/collection/analyticsjs/enhanced-link-attribution
  3. Anonymize IP addresses
     • No longer relevant. See https://support.google.com/analytics/answer/2763052

Screenshots:

Detailed test instructions:

1. Build extension from fix/tracking-for-purchases-and-admins
2. Go to Tag Assistant and debug site
3. While logged in as an admin, confirm that no tracking is sent
4. Logout
5. Open an incognito window and ensure all options are selected in WooCommerce > Settings > Integrations > Google Analytics
6. Confirm events are tracked
7. Place an order and confirm a purchase event is sent
8. Refresh the thank you page and confirm a second purchase event is not sent
9. In the incognito window, disable some events like Add to Cart Events and Product Detail Views
10. In the non-incognito window, confirm that those events are no longer sent

Additional:

I believe we can remove a couple of the other settings but as we're close to release I decided to only remove settings that explicitly state they are not support by GA4. If any other changes are needed that can be addressed post launch.

Changelog entry

Fix - Prevent tracking orders multiple times and additional fixes

[tomalec]

Thank you for fixes and cleanups!
Reviewed the code, tested locally, LGTM :)

The only comment I have is that as we remove ga_standard_tracking_enabled setting from here, we need to accommodate for that change in GLA integration.

[martynmjones]

Thank you for fixes and cleanups! Reviewed the code, tested locally, LGTM :)

The only comment I have is that as we remove ga_standard_tracking_enabled setting from here, we need to accommodate for that change in GLA integration.

Thanks @tomalec! The standard tracking reference in GLA is addressed in woocommerce/google-listings-and-ads#2297