Is it possible to get the old value from an observer?
Simple use case: If a user changes the name of a layer, I would like to get the old name of the layer and the new name. If onLayerChanged
provided arguments like (layers, new_layer, old_layer) this would be possible.
Can the method not provide this information because the old layer information has already been changed/deleted by the time onLayerChanged
is called?
Is the best solution to just save all layer names and then iterate for the one whose name no longer exists in onLayerChanged
and assume that is the changed one?