How to automatically update variable whenever the attribute value changes without writing 5 extra lines of code

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#1 
function SyncToAttribute(target, name, variable)
	local function sync()
		variable = target:GetAttribute(name)
	end
	sync()
	target:GetAttributeChangedSignal(name):Connect(sync)
end

local HeadHorFactor = 0
SyncToAttribute(script, "HeadHorizontalFactor", HeadHorFactor)

I want to update the variable whenever attribute value changes but I dont want to write 5 extra lines of code for every variable that I want to sync with attribute. How can I do that? Since I cannot change variable contents, only in the scope.

I also tried to do this with Proxy module but I kept getting “C stack overflow” errors.

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#2

I don’t understand your question, it’s hard to read - sorry. Could you clarify it a bit?

It sounds like you just want an array of attribute names (or use GetAttributes to get a key/value of all of them) and then use a for loop to connect a changed signal to each one.

#3

I want to update my variable whenever the attribute value changes using a function instead of writing 5 lines of code for each variable.

local y = script:GetAttribute("y") --> 0
print(y) --> 0
script:SetAttribute("y", 1)
print(y) --> 0
-- as you can see, y still gives 0

There is a solution to do that, but its cluttering my code

local TurnCharacterTowardsMouse = false
local function UpdateTurnCharacterTowardsMouse()
	TurnCharacterTowardsMouse = script:GetAttribute("TurnCharacterTowardsMouse") 
end
script:GetAttributeChangedSignal("TurnCharacterTowardsMouse"):Connect(UpdateTurnCharacterTowardsMouse)
UpdateTurnCharacterTowardsMouse()

So I want to make function that updates the variable whenever the attribute value changes instead of writing this mess above. Such as SyncWithAttribute(script, "TurnCharacterTowardsMouse", TurnCharacterTowardsMouse).

#4

Unfortunately Lua cannot allocate variables this way. You will have to stick with other alternatives.

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#5

You can do this:

local function attributeChanged(attributeName)
	getfenv(0)[attributeName] = script:GetAttribute(attributeName)
end

script.AttributeChanged:Connect(attributeChanged)

The variable names must be the same as the attribute name for this to work. Consider the comment below.

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#6

You’re going to need that boilerplate. Variable definition in Luau hasn’t changed with the addition of attributes, the value of a variable will be whatever it is at the time of assignment. You need to update it yourself, even if it’s just as simple as using GetAttribute just before using it.

I do not recommend the above code because using getfenv/setfenv disables Luau optimisations.

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