Getting a node from a child on ready

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:information_source: Attention Topic was automatically imported from the old Question2Answer platform.
:bust_in_silhouette: Asked By Elis

Hi,

I have a structure set like this:

    - Map (main scene)
    -- Player (sub scene, instanced)
    -- TileMap

On my Map.gd, I’ve set an onready variable like this:

onready var tilemap = get_node("TileMap")

which works fine, obviously.

However, if in my player.gd I set this:

onready var tilemap = get_parent().tilemap

It doesn’t work, and return null, while

onready var tilemap = get_parent().get_node("TileMap")

works fine.

Is this a bug, or just something I’m not understanding well?

2
:bust_in_silhouette: Reply From: kidscancode

_ready() is called on children first. Or to be more specific, _ready() is called on a node once all of its children are ready.

onready var tilemap = get_parent().tilemap

This doesn’t work because the parent’s _ready() function hasn’t run yet, so the value of tilemap hasn’t been set.

Rather than use get_parent(), you should call down the tree. On your Map script, tell the player about the tilemap:

$Player.tilemap = $TileMap

It’s generally good practice for parents to manage children, not the other way around. Imagine if you run your player scene separately for testing. If there’s a get_parent() call in there, it will crash. Instead, this way the parent “tells” the player what it needs to know when it’s part of the map.