Update X/Y or Lat/Lon Fields

Writes coordinate fields onto a layer: either POINT_X / POINT_Y in the layer's own CRS, or LONGITUDE / LATITUDE in WGS 84. The fields are created if they are missing.

This is the field-book direction: a point layer that has to go into a report, a handover spreadsheet or a GPS device needs its coordinates as attributes, not only as geometry. Lines and polygons get their centroid, which is what a "location of this feature" column usually means.

1. Open KGA Geometry Utilities > Update X/Y or Lat/Lon Fields.
2. Pick the Input Layer.
3. Choose the Coordinate Format. Pick Lat/Lon when the numbers are going somewhere outside this project — a report, a GPS, a spreadsheet a colleague will open.
4. Press Run. A message box reports what happened.

• Lines and polygons get their centroid, which for a concave or ring-shaped polygon can fall outside the feature. If the point has to be inside, use Geometry Conversion with Point on Surface instead.
• The changes are committed immediately — no dry run, no edit session left to undo from.
• Existing values are overwritten. The field names are fixed; the tool does not ask before reusing POINT_X or LONGITUDE if the layer already has one.
• Running it twice with different formats leaves both pairs of fields on the layer.
• Features with null or empty geometry are skipped.
• A coordinate that cannot be transformed is reported in the log and that feature is skipped, rather than stopping the run.
• The values are a snapshot. Move a feature afterwards and the fields are stale — run it again.
• The tool needs iface for its message boxes, so it cannot run headless.