Update tracking for blocks

[martynmjones]

Changes proposed in this Pull Request:

Closes #268

Tracking for blocks only supports Universal Analytics as it currently stands. This PR updates the tracking for GA4 and removes references to UA documentation.

Screenshots:

Detailed test instructions:

view_item_list

1. Create a page using the All Products block and view page in incognito with GA Debug enabled (Alternatively use Tag Assistant to monitor events)
2. Confirm that on the initial page load a view_item_list event is triggered with the correct parameters
3. Click on the second page of the product listings and confirm that only one new view_item_list is triggered and that it matches the above data structure.

add_to_cart

1. On the All Products page, click Add to cart for a product
2. Confirm that an add_to_cart event is triggered with the correct parameters

remove_from_cart and change_cart_quantity

• These events can be ignored with this PR. The experimental hooks in blocks don't work well for how GA4 expects the remove_from_cart event to work. Issue with tracking quantity changes in cart #312 has been opened so that this can be addressed in a follow-up PR.

begin_checkout

Note: The experimental__woocommerce_blocks-checkout-render-checkout-form hook which the begin_checkout event relies on doesn't currently work. Reported in woocommerce/woocommerce-blocks#11472.

1. To test this event, go to the block-powered checkout page, apply a coupon, and run the following in console:

wp.hooks.doAction('experimental__woocommerce_blocks-checkout-render-checkout-form', { storeCart: wp.data.select('wc/store/cart').getCartData() } );

2. Confirm that the begin_checkout event is triggered with the correct parameters and that item quantities and coupon name are correct in the event data

add_shipping_info

1. Add more than one shipping option to the test site
2. Select an option during checkout and click Place Order
3. Confirm that the add_shipping_info event is triggered with the correct parameters

select_content

1. Go to a page with the All Products block
2. Click on a product
3. Confirm that the select_content event is triggered with the correct parameters

search

• Doesn't work at the moment. Also reported in Two documented hooks aren't dispatched when expected woocommerce-blocks#11472.

Changelog entry

Update - Tracking for GA4 when using Blocks

[tomalec]

The Google documentation states that the price parameter should be a number, but we're sending string

[tomalec]

Reviewed the code tested locally.
My only concern is the price data type.
Other than that, LGTM.

[tomalec]

📜 💅
If I understand the docs correctly, this id is to identify the list from which we're reporting.
With blocks, we can have multiple lists on different pages. But currently, we send engagement regardless of which list we track. Maybe we could somehow forward the block instance id, or at least page ID?

[martynmjones]

That would be a nice addition! I've opened issue #324 so as to not get off track in this PR.

[tomalec]

Documentation states it should be a number, we send a string.

[martynmjones]

Nice catch! Updated in 4a06f52

[tomalec]

❔
I wonder if the empty "" in case of lack of coupon is the most accurate representation. Shouldn't we just don't send this property in case of lack of coupon? I'm not sure how the value being set (event to empty string) would be interpreted.

[martynmjones]

That's a good point. I'm not sure what the behavior would be and from a quick search I couldn't find any thing in the GA documentation about it 🤔 I've updated how it works in 813b7ee so we're not including an empty string.