Enable auto generation of ids for GeoJSON sources

[asheemmamoowala]

Closes #6849.

Upgrades geojson related libraries to include auto-generation of ids for geojson features and clusters.

cc @ryanbaumann

[mourner]

👍 Looks good! Although worth noting that I just realized that Supercluster doesn't have an equivalent of generateId option, so if the original GeoJSON doesn't have id in features, they will only be present for the clusters, not the points. Should we add it there as well? Should be trivial.

[andrewharvey]

It looks like this is only done when you initialise a new GeoJSON source, if you subsequently use setData I assume generateId won't apply ids then? I think the behaviour should be made explicit somehow in the docs.

[asheemmamoowala]

It looks like this is only done when you initialise a new GeoJSON source

@andrewharvey it should generate ids every time. workerOptions is built up in the constructor and is reused in calls to _updateWorkerData.

I just realized that this is somewhat of a problem though. id's are based on the index of elements in the features array, so they can change on subsequent calls to setData. This would mean any previously cached feature ids would point to a different feature after the new tiles are rendered. This would need documentation, but I also think that it is not a good API experience.

[andrewharvey]

I just realized that this is somewhat of a problem though. id's are based on the index of elements in the features array, so they can change on subsequent calls to setData. This would mean any previously cached feature ids would point to a different feature after the new tiles are rendered.

Previously cached internally to GL JS or by the user outside GL JS? I should be fine if ID's change since you're resetting the data anyway, and anyone who needs stable IDs can provide their own.

[asheemmamoowala]

Supercluster doesn't have an equivalent of generateId option, so if the original GeoJSON doesn't have id in features, they will only be present for the clusters, not the points. Should we add it there as well?
@mourner -> mapbox/supercluster#97

[asheemmamoowala]

Previously cached internally to GL JS or by the user outside GL JS?

@andrewharvey this would be both. setData needs to clear the corresponding feature state cache internally, and any feature ids cached or used externally will also need to be invalidated.

[hoogw]

How to use auto-generated-ID?
feature.id ?

[asheemmamoowala]

@hoogw You can enable id generation by setting the generateId flag on your GeoJSON source.

[hoogw]

@asheemmamoowala
excellent! well done !

What if I have type: vector instead of type: geojson

I want to use map.setFeatureState(), have to have a unique id,
but the source from mapbox-tilesets ( or mapserver .... .pbf) do not have a id field, no unique value column.

How to get "generateid" ?

[hoogw]

this works fine.

            ` map.addSource("_geojson_source", {
          "type": "geojson",
          "data": ___GeoJson,
          
          
          // https://docs.mapbox.com/mapbox-gl-js/style-spec/#sources-geojson-generateId
          //https://github.com/mapbox/geojson-vt/pull/109
          //https://github.com/mapbox/mapbox-gl-js/pull/7043
          "generateId":true
          
          
          });`

"generateId":true also works in vector source?
If not, how to deal with vector source, to use map.setFeatureState() ???

                   `map.addSource("_tilesets_source",  {
                    type: 'vector',
                    url: 'mapbox://hoogw.aiuo72ew'

                     // ????
                       "generateId":true   // ??????
                    });`

and this ???

                 map.addSource("_tileserver_source",  {
                    type: 'vector',
                  
                    "tiles": ["http://localhost:10/tileserver/news-freedom-rank-2019/{z}/{x}/{y}.pbf"],
                    
                      // ????
                   "generateId":true,   // ??????

                    "minzoom": 0,
                    "maxzoom": 22
                    
                    });