How can I tell if a variable is a supported attribute type?

[FroDev1002 (FroDev)]

So what I want to do is make a script that loops through a table, for every item I would want to tell if what it is, is a supported attribute type, likes strings, booleans, etc. I was just going to write out a table of all the types, but I thought I’d ask first so I dont have to waste time lol.

So is there a way to tell?
~ Frodev

[pullman45]

If there’s no other easy way I figure a hacky solution could be you try calling set attribute on some placeholder instance for every type and then wrap that call in a pcall so that if it catches an error you know the passed in type is invalid. Not a huge fan of using pcalls like this but it guarantees your code works, so if every other solution is too tedious this could be an acceptable method to use.

[OniiSamaUwU (UwU)]

If you don’t want to premake a table of supported attribute types, you can go with @pullman45’s answer and simply cache the results.

--!strict

local VALID_TYPES: {[string]: boolean} = {}

return function<T>(value: T): boolean
	if value == nil then
		return true
	end
	
	local valueType: string = typeof(value)
	
	if VALID_TYPES[valueType] == nil then
		-- we don't have to worry about destroying
		-- since this will get garbage collected anyways
		local success: boolean = pcall(function(): ()
			local instance: Instance = Instance.new("Folder")
			instance:SetAttribute("_", value)
		end)
		
		VALID_TYPES[valueType] = success
	end
	
	return VALID_TYPES[valueType]
end

--!strict

local IsValidAttributeType = require(script.Parent)

print(IsValidAttributeType(nil)) -- true
print(IsValidAttributeType(0)) -- true
print(IsValidAttributeType("Hello, World!")) -- true
print(IsValidAttributeType(Enum.KeyCode.A)) -- true
print(IsValidAttributeType(workspace)) -- false

[0786ideal (ideal)]

if typeof(Instance:GetAttribute("EXAMPLE")) == "boolean" then
-- code
end

[HDAdm_n (BENOFFICIAL)]

This should make sure that not only it’s the correct attribute type, but also it’ll still error if you’re doing something wrong that isn’t related to the type.

--!strict
local newInstance = Instance.new("Folder"):
local isCorrectType, info = pcall(function()
    return newInstance:SetAttribute("Your attribute")
end
newInstance:Destroy()
if not isCorrectType and not info:Find("is not a supported attribute type") then
    error(info)
end

If you really want you can make a function of it.
When using pcall for those kind of stuff I reccomend only disallowing certain errors, so in case you get an error that is different you won’t be confused as to what is wrong (Though here it will obviously not error but just for future practices)