Best way to handle character loading

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1

You can write your topic however you want, but you need to answer these questions:

  1. What do you want to achieve? Keep it simple and clear!

I would like to prevent routine errors I get that all fall into a category of “attempt to index nil with…”

  1. What is the issue? Include screenshots / videos if possible!

I have hundreds of references to player (or NPC) attributes, such as Humanoid, HumanoidRootPart, Head, Torso, etc. And also some folders I have as descendents of the player. Most of the time these references work fine, but occasionally (and too often for a well functioning game) I get an error along the lines of "attempt to index nil with [whatever I am referencing]. I am assuming this is because the player model (or NPC model) is not fully loaded when the lines of code are run - but this is a bit confusing to me because many times the errors occur in the middle of the game.

  1. What solutions have you tried so far? Did you look for solutions on the Developer Hub?

I’ve tried a number of solutions - many which seem to work but I don’t have strong confidence in the right uniform approach and the approach that can best scale the most efficiently across these hundreds of references. In some cases my solutions check to see if player or character or humanoid or (etc) exist before using it in a line of code. In other cases I prefer to be waiting for the player / character / etc to load before taking action. Here are some of the solutions I am using:

(1) if player and player.Character then… OR other times if humanoid then…

(2) local function onCharacterAdded(character)
local char = character
hrp = char.HumanoidRootPart
– Use char and hrp variables as needed in the rest of the script
end

(3) local function getUniversalModelHumanoidRootPart(instance)
local character = instance.Character
while not character or not character:FindFirstChild(“HumanoidRootPart”) do
character = instance.Character
wait()
end
return character:FindFirstChild(“HumanoidRootPart”)
end

(4) local humanoidRootPart = character:WaitForChild(“HumanoidRootPart”)

(5) local humanoidRootPart = character:FindFirstChild(“HumanoidRootPart”)

(6) local player = game:GetService(“Players”):GetPlayerFromCharacter(playerModel)
local Character = player.Character or player.CharacterAdded:wait();
repeat wait() until Character:FindFirstChild(“HumanoidRootPart”)

I would like to settle on a consistent, repeatable, efficient, performant, and reliable approach for this recurring issue.

After that, you should include more details if you have any. Try to make your topic as descriptive as possible, so that it’s easier for people to help you!

-- This is an example Lua code block

Please do not ask people to write entire scripts or design entire systems for you. If you can’t answer the three questions above, you should probably pick a different category.

2

Personally I use this

local char = player.Character or player.CharacterAdded:Wait()
local hrp = character:WaitForChild(“HumanoidRootPart”)

This works perfectly fine for me. One thing that I don’t suggest doing is ever actually “killing” the player. This can lead to errors if you try and call on parts of the character. Instead, you can “kill” the player by inserting a “health” numbervalue into the player and then moving their HRP to somewhere else or something…
Also, resetting is normally something I would disable but it’s relatively important that you have a method to get someone unstuck.
Adding to this, if you need a consistent reference to something, and not a one off, use a Connection with the CharacterAdded event. This will normally not error.
However, if you are worried about lines not running due to errors, I suggest using pcalls to allow your script to progress or do something special.
e.g. its a round system and the player died just as they got teleported. it errors because their HRP is nil. Using a pcall, we can tell the player that we were unable to teleport them, and continue the script.
Of course, you can just ignore all that by using a :WaitForChild inside this connection.
I hope this helped!

3

In light of Roblox still having difficulty fixing the ordering of avatar loading events and characters not being loaded atomically, you’ll have to create something that can roughly guarantee the character subtree loads when you access it. A simple method of doing this is declaring the character via a RemoteEvent, meaning the server tells the client when the character is parented.

Promises can make the client-side structure better and much easier to work with, but otherwise below I’ve shared some code from my replication experiments place file that shows how you can guarantee a child of the character exists the moment you access it with dot syntax.

Server:

local Players = game:GetService("Players")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local ReplicateRemote = ReplicatedStorage.Replicate

local function playerAdded(player)
    -- FIXME: This leaks memory because player is accessed in characterAdded
	local function characterAdded()
		player.Character:GetPropertyChangedSignal("Parent"):Once(function ()
			if player.Character.Parent == workspace then
				ReplicateRemote:FireClient(player, player.Character)
			end
		end)
	end
	
	player.CharacterAdded:Connect(characterAdded)
	if player.Character then
		characterAdded(player.Character)
	end
end

Players.PlayerAdded:Connect(playerAdded)
for _, player in Players:GetPlayers() do
	playerAdded(player)
end

Client:

local Players = game:GetService("Players")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local LocalPlayer = Players.LocalPlayer
local ReplicateRemote = ReplicatedStorage.Replicate

--[[
Promise.fromEvent(ReplicateRemote.OnClient, function(character)
    -- Do something with the character or assign it
    -- to a forward-declared variable maybe.
end)
]]
ReplicateRemote.OnClientEvent:Connect(function (character)
	print(character.Humanoid)
end)

This also works with attributes if you like instead. Just be wary that this may not work for dynamically added instances on characters; it only guarantees the subtree of the character prior to being parented, so the core components of characters (e.g. HumanoidRootPart and Humanoid).

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