Manually creating or copying an auxiliary table in QGIS 3 with Python

Question

I have a local layer which gets updated every now and then by being copied from a WFS. The local layer has some labels shown and some hidden through auxiliary table, because QGIS seems to only accept a very specific auxiliary table to show/hide labels through labels toolbar.

What I am trying to do is to create or copy the existing auxiliary table from the old local layer to the newly created local layer with python. I've been trying some methods from here. But with little success.

I know that I can also create a Boolean field in a shapefile and point there for show/hide label. But doing that makes me unable to use show/hide label button in the toolbar. So that is not ideal.

Answer 1

Change layer names in the script to your layer name, then run the script.

source_layer = QgsProject.instance().mapLayersByName("source_layer_name")[0]
target_layer = QgsProject.instance().mapLayersByName("target_layer_name")[0]

source_al = source_layer.auxiliaryLayer()
target_layer.setAuxiliaryLayer(source_al)

target_layer.setLabelsEnabled(True)
target_layer.setLabeling(source_layer.labeling())

iface.mapCanvas().refresh()