Identify clicked feature in external Python script for QGIS layer action

Question

I use the action editor in QGIS to code an action, but I want to move the code to a PyQGIS script and import it to the action instead of directly typing it in the action editor.

I changed this line

lyr = QgsProject.instance().mapLayer('[% @layer_id %]')

to

lyr = iface.activeLayer()

and I hope that this is correct (when importing iface). But how to access the clicked feature for the action? How does the following line need to be changed in order to remove the syntax that does not work outside the action editor window?

ft = lyr.getFeature([% $id %])

At least this last line is only working when typed directly in the editor window, see Importing .py script to action editor using QGIS.

• Andreas Müller: $id will be the features id, the user clicked on. To get that, you need to use Qt's signal&slot and trigger the action from your script. I would stay with your layer action, the docs have an example to write python code for a layer action: docs.qgis.org/3.28/en/docs/training_manual/create_vector_data/…
• Andreas Müller: by the way, what do you mean by "external script"? You can't use iface outside of qgis and you can't get the result of a user interaction from outside. So, what is your goal of your efforts?
• winnewoerp: Thank you, I edited and (hopefully) clarified my question.