IIRC, pagination is disabled because there is no way to paginate in the UI, so we want to return every pattern from the API for local filtering. Is there a reason to request just 2 patterns here?

I think this needs to change from unsetting entirely, to support the params and set defaults or make the other request to pass -1 to fetch all. The API needs to support other use cases as well besides the pattern directory UI.

Is there a reason to request just 2 patterns here?

2 was just for demo and I guess we will show a bit more - maybe 10 or something? I believe we have to have a limit though because of performance and the current UI for selecting patterns, which is not super friendly for previewing a large number of patterns. We can revisit of course later..

Turns out I was misremembering slightly - the wp.org API does not support pagination, it always requests 100 patterns. If/when we revamp the pattern inserter, we can update the API to support pagination, and then we can reenable these params here. For now, the featured category is manually curated, so you can be sure it's a smaller list.

Some of these same patterns are already being registered with the prefix core/ and there's no prefix here, so I'm seeing a few duplicates in the featured tab: core/heading and heading, core/large-header-with-left-aligned-text and large-header-with-left-aligned-text, etc.

hm... I updated with a check if a pattern is registered with the core prefix. This made me wonder why we need the core prefix in the first place.. Should we also incorporate the id that exists in pattern directory in is_registered?

I'm noticing some things that are slightly tangent to this PR, but I'll still mention them:

• As in the previous function, the pattern's title is sanitised but the rest of the payload isn't, neither here nor in the patterns registry class. Seems like a code smell to me — either we are oversanitising or undersanitising.
• Though it's not the only case in WP, I've always found it very odd that the backend should make a HTTP request to itself. :) I don't know what arguments support this against just querying directly.

Good questions Miguel. @ryelle does the sanitisation has to do with the current way the patterns are included in the directory? The inclusion happens manually for now so it's sanitised by 'us'?

I agree that such questions/changes can happen in a separate PR.