:UpdateAsync() Saying "Unable to cast value to function."

Help and Feedback Scripting Support
#1

I’m simply having an issue that I’ve looked around for but couldn’t find a solution for. Every time it tries to run it returns with “Unable to cast value to function.”

local DSS = game:GetService("DataStoreService")
local statStore = DSS:GetDataStore("statStore")

game.Players.PlayerAdded:Connect(function(plr)
	
	local plrId = plr.UserId
	
	local data = statStore:GetAsync(plrId)
	
	local leaderstats = Instance.new("Folder", plr)
	leaderstats.Name = "leaderstats"
	
	local wins = Instance.new("IntValue", leaderstats)
	wins.Name = "Victories"
	
	if data then
		wins.Value = data["Victories"]
	else
		wins.Value = 0
	end
end)

local function create_table(plr)
	local player_stats = {}
	
	for _, stat in ipairs(plr.leaderstats:GetChildren()) do
		player_stats[stat.Name] = stat.Value
	end

	return player_stats
end

local function onPlayerExit(plr)
	
	local player_stats = create_table(plr)
	
local plrId = plr.UserId
	local success, errorMessage = pcall(function()
		statStore:UpdateAsync(plrId, player_stats)
		print("Player had data, using :UpdateAsync()")
	end)

	if not success then
		task.wait(2)
		onPlayerExit(plr)
		print("Player had an error whilst saving data. Retrying...")
	end
end

game.Players.PlayerRemoving:Connect(onPlayerExit)

while true do
	for i, v in pairs(game.Players:GetChildren()) do
		onPlayerExit(v)
	end
	task.wait(74)
end

game:BindToClose(function()
	for i, v in pairs(game.Players:GetPlayers()) do
		onPlayerExit(v)
	end
end)
#2

The UpdateAsync requires a key and a function in its arguments like this

local function ExampleFunction(oldValue)
	return oldValue + 100
end
exampleDataStore:UpdateAsync("ExampleKey", ExampleFunction)

In your case, I do not recommend to use UpdateAsync since the method is used for comparing the old value of the DataStore. I recommend SetAsync instead, but if you’d like to use UpdateAsync anyway:

local DSS = game:GetService("DataStoreService")
local statStore = DSS:GetDataStore("statStore")

game.Players.PlayerAdded:Connect(function(plr)
	
	local plrId = plr.UserId
	
	local data = statStore:GetAsync(plrId)
	
	local leaderstats = Instance.new("Folder", plr)
	leaderstats.Name = "leaderstats"
	
	local wins = Instance.new("IntValue", leaderstats)
	wins.Name = "Victories"
	
	if data then
		wins.Value = data["Victories"]
	else
		wins.Value = 0
	end
end)

local function create_table(plr)
	local player_stats = {}
	
	for _, stat in ipairs(plr.leaderstats:GetChildren()) do
		player_stats[stat.Name] = stat.Value
	end

	return player_stats
end

local function onPlayerExit(plr)
	
	local player_stats = create_table(plr)
	
	local plrId = plr.UserId
	local success, errorMessage = pcall(function()
		statStore:UpdateAsync(plrId, function(oldValue)
			return player_stats 
		end)
		print("Player had data, using :UpdateAsync()")
	end)

	if not success then
		task.wait(2)
		onPlayerExit(plr)
		print("Player had an error whilst saving data. Retrying...")
	end
end

game.Players.PlayerRemoving:Connect(onPlayerExit)

while true do
	for i, v in pairs(game.Players:GetChildren()) do
		onPlayerExit(v)
	end
	task.wait(74)
end

game:BindToClose(function()
	for i, v in pairs(game.Players:GetPlayers()) do
		onPlayerExit(v)
	end
end)
2 Likes
#3

Well… give me a minute. I’m trying to fix it up a little.

#4

Quick question. Does this also happen to save data for new players?

#5

Of course it does, why would it not?

1 Like
#6

I was just curious, since it never uses SetAsync. I thought that it had to have data to update, no?

#7

No, it doesn’t need to have data. UpdateAsync works like SetAsync, but takes the oldValue in consideration. If the oldValue is not important, then you should definitely use SetAsync. For example, if you have a key in your datastore that’s a rank, there’s no need to consider the old value. However, if you have a key that’s the highscore or something, you might wanna consider the old value.

2 Likes
#8

Well, thank you so much for helping me! I feel like I learned a lot on UpdateAsync and SetAsync. Thanks!

1 Like