Inherited class does not keep the properties of the base class

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,
1

Godot Version

I am on the Stable version of Godot 4.3

Question

Hi this might be a dumb question but I can’t really figure this out myself so I’m hoping to get some clarifications here.
In my game I have a Chara class with the following property.

var model_component: ModelComponent

In this case, ModelComponent refers to a simple class that only has the following.

extends Node3D
class_name ModelComponent

Now in the _ready() function of that Chara class I have, I set that property using this code.

func _ready():
	for child in get_children():
		if child is ModelComponent:
			model_component = child

Then I have another class named Hero that extends the Chara class, and in the _ready() function of that new class I call the _ready() function of the Chara class with this :

func _ready():
	super._ready()

Upon testing it the correct function gets triggered and thus the model_component property is assigned like I want to.
Unfortunately in Hero when I try to use that inherited reference (model_component) in another function it says the reference is null. Why?

2

Does your hero have a model component as a child? Can you show your scene tree?

3

Yes, sorry I should’ve specified that. I do have a hero scene with a CharacterController3D that has a hero.gd script which contains that Hero class and a Node3D as a child which is the ModelComponent.
image

4

Interesting, can you show the function where you get a null exception? Is there a chance it happens before _ready()?

5

This is where the exception occurs (this is a placeholder for testing).
image

It does get played once before the Hero’s _ready() but even after putting a return at the start of the function and checking during runtime in the _process function the reference stays null.
In fact, even after the super._ready() call in Hero’s _ready() the reference stays null.

6 
func _ready():
	super._ready()
	print(model_component)

This should print something if you have at least one valid ModelComponent as a child. This variable will certainly be invalid before _ready, so never try to use it before then.

7

Pretty late reply, sorry about that but I have more news on the problem.
This does print the model component so the inheritance thing seems to be working fine.
But now I have encountered a new issue.

print(chara.model_component)
chara.play_anim("Wait", 0.3)

I have this in another script, chara is a variable of type Chara and is a reference to the Hero node.
What is absolutely baffling me is that the first line actually does work and prints the model component but when I call the function with chara and I do this in the function :

print(self.model_manager)

It prints null. Why?

8

Nevermind! I just made a silly typo, I wrote “model_manager” instead of “model_component”.