Document that clustering requires GeoJSON sources

[jmkiley]

The documentation for MGLShapeSourceOptionClustered does not mention that you currently can only cluster shapes with a GeoJSON source. This may be confusing for users who want to cluster point annotations (#5814), for example.

/cc @1ec5 @friedbunny

[1ec5]

#7837 is adding this documentation.

[friedbunny]

Fixed in #7837.

[nitrag]

Why is clustering only available in MGLShapeSource and not MGLVectorSource? Is there some limitation?

[1ec5]

@nitrag, great question. According to @mourner, it has to do with the fact that the clustering algorithm needs all the data to be loaded, whereas with vector sources, tiles come in asynchronously. Please open a separate issue to request this feature. Be sure to explain your use case so we can discuss the best way to support it.

[jbarros35]

I wanted to do that dynamically. Using geoJSON files it's just stupid.

[michzio]

No it works for me with MGLPointFeature
I am doing MGLPointAnnotation to MGLPointFeature simple conversion

 let features = Array(mapPoints.values).map { $0.pointFeature }
        let source = MGLShapeSource(identifier: "clusteredRestaurantsSource",
                                    //url: url,
                                    features: features,
                                    //shapes: Array(mapPoints.values),
                                    options: [.clustered : true,
                                              .clusterRadius : icon.size.width,
                                              .maximumZoomLevelForClustering: 16])

[vikihleblya]

@michzio, please, can you say what type is mapPoints in your code? Do you request your points once or you do it periodically? My problem is that I request all my points for some area on screen and when I drag to other location, I request points again. That's why I can't fully understand at which sequence I need to code.