Implementing feature interactivity

At a high level I think feature interactivity can be split into two main pieces:

• RFC: Tracking feature state for interactivity https://github.com/mapbox/mapbox-gl-js/issues/6021
• RFC: Updating the appearance of individual features https://github.com/mapbox/mapbox-gl-js/issues/6020

Both of these proposals have plenty of other open questions that could be split into separate issues.

One open question is how to merge features across tile boundaries:

• RFC: Feature identity for interactivity https://github.com/mapbox/mapbox-gl-js/issues/6019

Next steps

@kkaefer @asheemmamoowala @mollymerp @anandthakker @mourner @lucaswoj

It would be good to get feedback on these proposals. What seems like a good idea and what doesn't? What alternative options did I miss?

After we figure out the high level direction we can start splitting up the design and implementation work into pieces.

@asheemmamoowala compiled list of all relevant issues:

Suggestions/Requests

• style-spec hover and active style properties: https://github.com/mapbox/mapbox-gl-js/issues/200
• feature-enter and feature-leave events: https://github.com/mapbox/mapbox-gl-js/issues/5539
• ray picking for selecting extrusions: https://github.com/mapbox/mapbox-gl-js/issues/3122
• optimize for hover and select: https://github.com/mapbox/mapbox-gl-js/issues/2874
• optimise setFilter: https://github.com/mapbox/mapbox-gl-js/issues/2443
• hover issues: https://github.com/mapbox/mapbox-gl-js/issues/550
• callouts for POIs: https://github.com/mapbox/mapbox-gl-native/issues/5432
• re-constitute query geometry for geojson:
  https://github.com/mapbox/mapbox-gl-js/issues/5639
  https://github.com/mapbox/mapbox-gl-native/issues/6178
  https://github.com/mapbox/mapbox-gl-native/issues/7376

Related tickets:

• js color expressions for highlighting: https://github.com/mapbox/mapbox-gl-js/issues/5676
• selection at tile boundaries breaks: https://github.com/mapbox/mapbox-gl-native/issues/10615
• iOS tap gesture for feature querying: https://github.com/mapbox/mapbox-gl-native/issues/6515
• query methods to work with raster layers: https://github.com/mapbox/mapbox-gl-js/issues/1404
• ignore holes in polygon query: https://github.com/mapbox/mapbox-gl-js/issues/2293
• string feature IDs: https://github.com/mapbox/mapbox-gl-js/issues/2716, -
• https://github.com/mapbox/vector-tile-spec/issues/94
• frequent geojson data updates: https://github.com/mapbox/gl-internal/issues/818
• improved event handling https://github.com/mapbox/mapbox-gl-js/issues/5818

Start by reading the linked RFC issues 6021, 6020, and 6019, along with the related tickets listed in this issue. The immediate work is to evaluate the proposed direction and unresolved questions, then split agreed design and implementation work into concrete follow-up issues. Done means the high-level direction has feedback and actionable follow-ups.