Scene instantiated but not added to the scene tree casues the parent node properties to be lost

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1

Godot Version

Godot v4.7.1 stable

Question

My first time using the forum! completely new to Godot and C# in general so sorry if the question being too native. Here I found a weird behavior occur to node referencing on scene that’s being instantiated outside of the scene tree. Where let’s say I have a main scene call MainScene and a EndScene I want to transit to. For EndScene its a Control node with a Label child node named TextHolder. The Control node has the following script

public partial class EndScene : Control
{
	private Label _TextHolder;
	public Label TextHolder
	{
		get => _TextHolder;
		set => _TextHolder = value;
	}
	public override void _Ready()
	{
		TextHolder = GetNode<Label>("TextHolder");
		TextHolder.Text = "Hello";
	}
}

And the EndScene scene is store at res://end.tscn. Now in the main scene script:

public partial class MainScene : Node2D
{
	private PackedScene End = GD.Load<PackedScene>("res://end.tscn");
	public override void _Ready()
	{
		EndScene endscene = End.Instantiate() as EndScene;
		endscene.TextHolder.Text = "Hi";
		GetTree().ChangeSceneToNode(endscene);
	}
}

Would result in the program getting stuck at the statment endscene.TextHolder.Text = "Hi"; due to endscene.TextHolder being null. If I remove this problematic line and run, the EndScene can display the text “Hello” which seems to indicate that EndScene.TextHolder works fine in EndScene script.

so I thought maybe all the child node instances after the _ready() function in EndScene would be discarded as I did not put the endscene to the scene tree which causes the reference type property TextHolder to be null. Yet if I use endscene.GetChilden() from the main script like such:

public partial class MainScene : Node2D
{
	private PackedScene End = GD.Load<PackedScene>("res://end.tscn");
	public override void _Ready()
	{
		EndScene endscene = End.Instantiate() as EndScene;
		GD.print(endscene.GetChilden());
	}
}

It will show that endscene indeed has a Label child node attach to it. So My question is, why does such a strange behavior happen which I can’t get the reference of the child node despite it is still there?

2

It’s not “strange behavior”. It behaves as expected. _Ready() runs after the scene is added to the scene tree. Since you initialize TextHolder in _Ready() in will be null until that.

3

Ah now I see, thank you very much! I was wrong because I thought Instantiate() would call the _Ready() function for some reason, at least now I know.