Nil error when trying to move Sprite

[Longchamps]

Godot Version

4.3

Question

I´ve been trying to code an starting map to check my Sprites movement.
Got a node structure like this:

Game
-Map
–EventHandler

For now the basic idea is that the game will take a Sprite 2D Character I made and an TileMapLayer I created, instantiate them as child nodes of the Map node and then let me move the character around with the arrow keys, The main problem happens when I try to move the character. This is the relevant code:

class_name Game
extends Node2D

const area_scene := preload("res://src/Entities/Areas/area1.tscn")
const character_scene := preload("res://src/Entities/Actors/character.tscn")

@onready var area: Area
@onready var map: Node2D = $Map

func _ready() -> void:
	area = area_scene.instantiate()
	map.add_child(area)
	map.read_area(area)
	var character: Sprite2D = character_scene.instantiate()
	map.add_child(character)
	map.generate_character(character)

class_name Map
extends Node2D

const area_scene := preload("res://src/Entities/Areas/area1.tscn")

@onready var character: Sprite2D 
@onready var event_handler: EventHandler = $EventHandler
@onready var entities: Node2D = $Entities
var map_data: MapData
var character_grid_pos: Vector2i
var tiles: Array[Vector2i]

func _process(delta: float) -> void:
	var action: Action = event_handler.get_action()
	if action is MovementAction:
		character_grid_pos += action.offset
		character.position = Grid.grid_to_world(character_grid_pos)
	elif action is EscapeAction:
		get_tree().quit()

func read_area(area: Area) -> void:
	tiles = area.tiles_list
	character_grid_pos = area.initial_position

func generate_character(chara: Sprite2D) -> void:
	chara.position = Grid.grid_to_world(character_grid_pos)

class_name Grid
extends Object

const tile_size = Vector2i(16, 16)


static  func grid_to_world(grid_pos: Vector2i) -> Vector2i:
	var world_pos: Vector2i = grid_pos * tile_size
	return world_pos


static func world_to_grid(world_pos: Vector2i) -> Vector2i:
	var grid_pos: Vector2i = world_pos / tile_size
	return grid_pos

class_name MovementAction
extends Action

var offset: Vector2i

func _init(dx: int, dy: int) -> void:
	offset = Vector2i(dx, dy)

[KingGD]

@Longchamps

@onready var character: Sprite2D

I think you never setup this, so give it a value in the generate_character function like this:

func generate_character(chara: Sprite2D) -> void:
    character = chara
	chara.position = Grid.grid_to_world(character_grid_pos)

[Longchamps]

Well I´ll be damned, that solved it perfectly! Thanks a lot man, mind if I pick your brain about why that happened? I don’t think I understand exactly what the problem was and how that single line solved it.

[KingGD]

@Longchamps

@onready var character: Sprite2D

Actually you forgot to set the value of this character, defaultly it is null, “Sprite2D” is a class name only. And I observed that you are changing its position in the process function, but it is null. So you need to set the “character” to real player (that character of sprite 2d).

@Longchamps

func generate_character(chara: Sprite2D) -> void:

You already passed the chara (character or player), just needed to give it to character, I means just need to set the character to chara, as character = chara. So its did not null anymore.