wc-settings dependencies can be enqueued too late

[mikejolley]

wc-settings script requires JSON encoded settings data to work. Currently, this data is enqueued when footer scripts are printed.

If another script has a dependency of wc-settings (or one of its dependencies has a dependency of wc-settings as we're seeing with plugins consuming the @woocommerce/block-checkout package), and this script is enqueued and printed in the header, wc-settings will be printed in the header as well. By the time the footer hook is called, it's too late:

https://github.com/woocommerce/woocommerce-gutenberg-products-block/blob/961c0c476d4228a218859c658c42f9b6eebfdec4/src/Assets/AssetDataRegistry.php#L63-L64

This results in console errors due to missing data.

An example of something which causes this, is using block.json and registerBlockType with editorScript defined. These scripts are output in the header, not the footer.

To fix this:

• enqueue_asset_data must be called in the header and footer in both admin and the frontend. If wc-settings is enqueued, the data must also be added inline at that point, otherwise it will be too late.
• enqueue_asset_data needs to only be ran once, so there is only one inline script containing the data, and data is only added to the page once.

Example: c71645c

There may be alternative approaches to this such as callbacks, or protection within wc-settings so it doesn't break when data is missing.

[mikejolley]

Related: Allow scripts registered via block.json to be enqueued in the footer

[mikejolley]

If you use "script" to register the frontend script of a block automatically, this also breaks wc-settings on the frontend. See here the scripts are loaded in the header:

https://github.com/WordPress/WordPress/blob/f57070bfd1a7f0b2d437678ae823c3329f83c264/wp-includes/blocks.php#L109-L114

The solution I tried doesn't work for this case because blocks register data on render. So that happens too late.

We'd need a callback or something to pass this data to the settings script for it to work, so it can accept data later on.

[mikejolley]

Closed by #5059