Motivation

You can cluster a GeoJSONSource, but it's difficult to filter out source data because the layer filter expression applies to the clustered features. The GeoJSONSource has a filter property, but it can only be specified on source initialization.

To paint an illustrative example, let's say we have 50K features with a date property and as a user interacts with our app, we allow them to filter the clustered map to just show features in a certain date range. If the 50K features weren't clustered, we could just apply a filter to each layer we wanted to filter. But with the 50K features clustered, we either need to filter the source data ourselves and use setData or we need to remove the source and add it back with a filter applied to it. The former requires source data regeneration on our end, and the latter results in a flash as the map removes all features from the old source and adds all features from the new source.

Thanks for your consideration, and also open to alternative ideas! ❤️

Design Alternatives

Would it be possible to add a setFilter method to a GeoJSONSource to allow for this workflow?

Design

Currently, it looks like the setData workflow in a geojson_source will kick off a loadData, which checks to see if there is a filter, and if so, does a data.features.filter. Since this setData workflow looks at the filter, it seems like setFilter could potentially be a subset of this workflow.

Mock-Up

Concepts

Implementation