Dan,
It looks like Stefan got you pointed in the correct direction. Let me
see if I can fill in a some more of the details:
1) It sounds like you will need to work with the features in a layer
selected by the user. To access the currently selected layers you need
to work with the LayerManager cla
Hei Dan,
you will need to work with FeatureCollections.
To extend a "layer" (i.e. a FeatureCollection) by an attribute requires
to create a new FeatureCollection/FeatureDataset with a
different/extended FeatureSchema. Then all features need to be copied
towards the new schema and the values set
