Scripting HelpersARCHIVE
A little piece of Roblox history. Preserved for everyone, one question at a time.Read about the archive →
All questions/Question #52791
✓ ANSWER ACCEPTED

How to make an object within a Module Script?

Asked 608 views1 answers

So I want to make an object that can be created in multiple scripts, so I went with this approach:

Module Script Example:

local module = {}

Object = {}

function module:constructObject(x, y)
	return setmetatable({x = x, y = y}, Object)
end
Object.__index = Object

function Object:getX()
	return self.x
end

function Object:getY()
	return self.y
end

return module

Now if I were to construct the object in another script written in the module above and call one of its methods, it would be considered to be nil. Is there a way around having to write object methods that are considered to be nil when called from a script that requires from the module?

AnonymousEdited

1 answer

✓ Accepted answer

Your wording is a bit confusing, but hopefully this will help. The way that I create object oriented style classes in Lua is with the closure-based objects described at the bottom of this page: http://lua-users.org/wiki/ObjectOrientationTutorial

Doing it this way, you can write your module script like so:

local MyModule = {}

function MyModule.new(x, y)
	local self = {}

	-- Local variables are private to your class
	local x = x
	local y = y

	-- Public variables can be created like this
	self.thisIsPublic = "Hello World"

	-- A private function
	local function CombineString(str)
		return str .. "!!"
	end

	-- A public function
	function self.PrintStuff()
		print(CombineString(self.thisIsPublic), x, y)
	end

	return self
end

return MyModule

Then in another script somewhere:

local MyModule = require(game.ServerStorage.MyModule)

local m1 = MyModule.new(4, 5)
print(m1.thisIsPublic)
m1.PrintStuff() -- Notice the . syntax, not :

local m2 = MyModule.new(1, 3)
m2.PrintStuff()
m1.PrintStuff()

Which outputs: Hello World Hello World!! 4 5 Hello World!! 1 3 Hello World!! 4 5

So you can see that every object you create this way is a seperate instance. I hope this helped.

AnonymousEdited Permalink

1 comment

0

So it seems that the table the module returns is the object (?). Thanks!

Anonymous#

This discussion is preserved as it was. New answers, comments, and votes are closed.