OOP Property Issue

Help and Feedback Scripting Support
#1

I’m just playing around with a couple of code, but stumbled upon either a bug or just a common mistake.

local newLaser = Laser.new(workspace.Origin)
print(newLaser.Origin.Name)

newLaser takes in an origin part and sets a made up proprty, Origin, to workspace.Origin.

function laser.new(origin)
	local newLaser = {}
	setmetatable(newLaser, laser)
	
	newLaser.Origin = origin
	
	return newLaser
end

In this line, it sets the origin, etc.

The error it puts out is,

ServerScriptService.Script:6: attempt to index nil with 'Name'

I’ve looked at tutorials on how to learn OOP, but they look exactly identical. Any help and knowledge appreciated.

#2

Try this out:

function laser.new(origin)
	local newLaser = {}
	
	newLaser.Origin = origin
	
	return setmetatable(newLaser, laser)
end
#3

I tried this method, it worked, but in the other OOP examples it did the same method as I did.

And in other modules it seemed to have worked aswell?

#4

That does not make any difference, I think its the argument named origin is the problem.

#5

I don’t understand? What do you mean by argument?

#6

Have you tried printing the result of origin, like typeof(origin), from the function laser.new(origin).

#7

Could you show your entire module script code?

#8

Nope, but when I used the print statement inside the function, it referenced to that specific part in workspace.

#9 
--// Variables
local laser = {}
laser.__index = laser

local visibleKey = "Visible"

local DIST = 100

--// Functions
function laser.new(origin)
	local newLaser = {}
	
	newLaser.Origin = origin
	
	return setmetatable(newLaser, laser)
end

function laser:Activate()
	local function createBeam(origin)
		local raycastParams = RaycastParams.new()
		raycastParams.FilterDescendantsInstances = {}
		raycastParams.FilterType = Enum.RaycastFilterType.Blacklist
		
		local raycastResult = workspace:Raycast(origin.Position, origin.CFrame.LookVector * DIST, raycastParams)
		
		if raycastResult then
			return raycastResult
		end
	end
	
	self.CurrentOrigin = self.Origin
	print(self.Origin.Name)
	
	repeat wait()
		local result = createBeam(self.CurrentOrigin)
		
		if result then
			print(result.Instance.Name)
			self.Status = "Success"
		end
	until self.Status == "Success"
end

function laser.__newindex(t, k, v)
	if k == visibleKey then
		if v then
			-- We'll do something later with these.
		else
			-- We'll do something later with these.
		end
	end
end

setmetatable(laser, {
	__newindex = function(...)
		laser.__newindex(...)
	end,
})

return laser
#10

I tested your setup, it successfully printed out the name of Origin. Is workspace.Origin getting deleted in any way?

#11

Nope. Just checked in studio, it’s anchored.

#12

Wait hold on. That’s the new code…

#13

Try this out, what does it print?

function laser.new(origin)
	local newLaser = {}

	newLaser.Origin = origin
	warn(tostring(newLaser.Origin))
	warn(typeof(newLaser.Origin))
	warn(tostring(newLaser.Origin.Name))

	return setmetatable(newLaser, laser)
end
#14

I believe your first method worked, it’s just that the original code was written in the same format as this one?

#15

I think I might’ve fixed it… I had to delete the __index function because it was OVERRIDING the original one set!