Object Oriented Programming Error

[MadionChooi (BLUE_maxjen)]

I tried to write my own metatable script but I end up with an error and I have no idea how to fix it.

local CSSComponent = {}
CSSComponent.__index = CSSComponent
CSSComponent.ClassName = "CSSComponent"

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

local Packages = ReplicatedStorage.Packages	

local Signal = require(Packages.Signal)

function CSSComponent.new()
	local Tags = {}
	setmetatable(Tags, CSSComponent)
	
	Tags = {
		["UsingMove"] = {};
		["Stunned"] = {};
		["Ragdoll"] = {};
		["Immunity"] = {};
	};
	
	return Tags
end

function CSSComponent:AddTag(List, Tag)
	if not self.Tags[Tag] then return end
	local relatedTag = self.Tags[Tag]
	
	for _, obj in pairs(List) do
		CollectionService:AddTag(obj, Tag)
		
		table.insert(relatedTag, obj)
	end
end

function CSSComponent:RemoveTag(List, Tag)
	if not self.Tags[Tag] then return end
	local relatedTag = self.Tags[Tag]

	for _, obj in pairs(List) do
		if CollectionService:HasTag(obj, Tag) then
			CollectionService:RemoveTag(obj, Tag)
			
			for number, instance in pairs(relatedTag) do
				if instance.Name == obj.Name then
					table.remove(relatedTag, number)
				end
			end
		end
	end
end

return CSSComponent

[MadionChooi (BLUE_maxjen)]

Dont mind the second image that I didnt write anything in the CSSComponent:AddTag, even tho I added it, it wont work

[drlandru]

You are supposed to use the :AddTag() Method on the Tags Variable

Tags:AddTag()

[fellow_meerkat]

@drlandru is right, the methods should be called on the constructed object, which will be passed as self when the function is called with a colon.

However, there are also some other small mistakes.

• In the constructor, you are declaring Tags, respectively self in the called methods. After setting the metatable, you are setting Tags to the table, losing the metatable in the process.

• The passed self is Tags, therefore Tags.Tags is nil, and Tags.Tags[nil] causes an error.

Update.

I haven’t had a chance to test the code, but this is it.

Code

local CSSComponent = {}
CSSComponent.__index = CSSComponent
CSSComponent.ClassName = "CSSComponent"

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

local Packages = ReplicatedStorage.Packages

local Signal = require(Packages.Signal)

function CSSComponent.new()
	local Tags = {
		["UsingMove"] = {};
		["Stunned"] = {};
		["Ragdoll"] = {};
		["Immunity"] = {};
	}
	setmetatable(Tags, CSSComponent)

	return Tags
end

function CSSComponent:AddTag(List, Tag)	
	if not self[Tag] then return end
	
	for _, obj in List do
		CollectionService:AddTag(obj, Tag)
		table.insert(self[Tag], obj)
	end
end

function CSSComponent:RemoveTag(List, Tag)
	if not self[Tag] then return end

	for _, obj in List do
		if CollectionService:HasTag(obj, Tag) then
			CollectionService:RemoveTag(obj, Tag)
			
			table.remove(self[Tag], table.find(self[Tag], obj))
		end
	end
end

return CSSComponent

[Primotivos (Kibo)]

The :AddTag method should be for the ‘Tags’ variable, when the main function of the module’s been called.

local Tags = CSSComponent.new()
Tags:AddTag()