EDIT: here's a more concise way of wording the problem:
I need a way to either:
a) change the value of a variable that is in a script attached to an instantiated node/scene
or b) call a function in a script attached to an instantiated node, to then change the variables/scene
Both need to be able to be done when the scene is instantiated.
I'm making a satellite simulator.
I have a base satellite scene that has the satellite script attached to it. This script (satellite.gd) holds everything about the satellite - name, file path (where the satellite coordinates are located), etc. This script then sets the position of the satellite every frame.
I then have a separate script attached to a node that's always in the scene tree.This script (satellite_builder.gd) loops through a JSON that contains the info for every satellite (name, file path, etc.) and instantiates the base satellite scene in the scene tree.
However, now I need to be able to take the name and file path form the JSON (just strings) and set it to the instantiated satellite.
I tried this:
for sat_index in satellite_config.size():
var new_satellite = load("res://satellite_visualisation/satellites/satellite.tscn").instance()
var sat_name = satellite_config[sat_index]["name"]
var file_path = satellite_config[sat_index]["file_path"]
var time_resolution = satellite_config[sat_index]["time_resolution"]
new_satellite.setup(sat_name, file_path, time_resolution)
Then in setup() in satellite.gd, I set the name, file path variables, etc.
However, this throws the error:
"Attempt to call function 'setup' in base 'null instance' on a null instance"
Even though setup() is in satellite.gd
Then I tried just setting the variables directly like:
new_satellite.name = satellite_config[sat_index]["name"]
new_satellite.file_path = satellite_config[sat_index]["file_path"]
but that threw the error
"Invalid set index 'file_path'"
(interestingly it could set 'name' properly, but not anything else - the variable name for 'name' was highlighted light blue in the editor and nothing else was, if that helps).
Essentially, how can I change the value of a variable stored in a script that's on an instantiated node, from a non-instantiated node?