Keep feature.id as cluster_id even when promoteId is set to something else

[geirmarius]

Motivation

Currently trying to add a hover effect to my clusters, but setFeatureState cannot target the clusters as they do not have any ID. The reason being my promoteId is set to a custom property from my GeoJSON source.

Design Alternatives

Suggestion 1

Ignore promoteId for cluster features.

Suggestion 2 - follow the spec

The style spec says that you can target individual layers for promoteId, but this is false. Setting promoteId as following does not work:

...
promoteId: {
  'some_layer_id': 'some_prop',
  'cluster_layer_id': 'cluster_id',
},
...

If this was to work as the style spec suggests, it would solve the problem.

Design

As suggestion 2 is already following the spec, I assume that would be the most correct way of implementing it, but I don't see any drawbacks with suggestion 1.
Suggestion 1 has the advantage of working without having to specify layer source ids - this can be especially painful if you have a lot of layers you need to target.

Mock-Up

It will not make any changes, except following the spec if that suggestion is chosen.

Concepts

Should add a note in the spec that clusters will use cluster_id instead of promoteId, if suggestion 1 is accepted.

Implementation

I do not have enough knowledge of the mapbox internals to answer this 😅

---

End notes

Thanks for taking the time to read my suggestion. If there already is a solution to my problem, I've not found it and would love to be pointed in the right direction. Even so the spec do tell me something that is not true, so I believe this will need to be solved either way. In any case, thanks again, and if my issue has problems, or I misunderstood some of the headers, please correct me! 😁

[palhal]

I'm also having this problem. Would love to see this fixed. I created a live demo here: https://jsfiddle.net/pkhalle/cjxz0kdb/

[demiurg]

also a problem

[popkinj]

I just submitted a draft PR for this. maplibre/maplibre-gl-js#4899