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Field values

The Field Values chart source builds inline pie charts from selected properties of a GeoJSON or FlatGeoBuf vector dataset on the layer. There is no external CSV; the values are read from the feature itself when the user clicks it.

When to use

  • A vector dataset where each feature carries multiple numeric breakdown columns (e.g. land-cover percentages, voting shares, sector mix per polygon).
  • You want a pie chart per feature in the info panel without serving a separate CSV.

Configure

  1. The layer must have a GeoJSON or FlatGeoBuf data source on the Datasets tab.
  2. In the layer's Charts tab, click Add Chart and choose Field Values.
  3. The Field Values selector dialog opens, listing every property detected on the dataset. Tick the properties to include as pie slices.
  4. The selected names are stored in charts[].sources[0].fields with type: "inline".

The runtime reads each selected property from the clicked feature and builds the pie at view time, using the trace styling from the visual editor.

Notes

  • Property auto-detection uses the FlatGeoBuf header where available, or samples the first feature for GeoJSON.
  • Non-numeric properties are filtered out of the picker.