class()

A super simple module for defining Lua classes.

This was designed for use with Roblox, and as such follows their commonly used OOP conventions, but it works just fine in any Lua project.

Usage

local class = require(game.ReplicatedStorage.Class)

local Person = class("Person")

-- This method defines the parameters your class takes
function Person:__init(name, age)
	self.Name = name
	self.Age = age
end

function Person:Greet()
	print("Hi, my names " .. self.Name .. " and I'm " .. self.Age .. " years old.")
end

-- To instantiate, you call the `new` function
local person = Person.new("John", 18)

person:Greet() -- "Hi, my names John and I'm 18 years old."

Inheritance

To make a class inherit another, you pass in the class you want to be inherited as the second argument.

The only thing you need to do manually is call the __init method of the superclass, otherwise you won't inherit the super's properties.

The superclass is also returned after the newly created class so that you can create a reference to it. This saves you the trouble of using a direct reference to the superclass, and having to change it everywhere if you want to inherit something else.

-- This example continues from the one above

local Guy, super = class("Guy", Person)

function Guy:__init(name, age, manliness)
	-- This calls Person.__init on this instance, and sets the `Name` and `Age`
	-- properties for you.
	super.__init(self, name, age)

	-- Now we can extend it and add on our properties.
	self.manliness = manliness
end

function Guy:AttackABearOrWhateverGuysDo()
	if self.manliness > 50 then
		print("I could totally fight that bear.")
	else
		print("Here lies " .. self.Name .. ". He tried to fight a bear.")
	end
end

local guy = Guy.new("John", 18, math.huge)

guy:Greet() -- "Hi, my names John and I'm 18 years old."
guy:AttackABearOrWhateverGuysDo() -- "I could totally fight that bear."

If your subclass does not change anything about the parameters it takes, you don't need to create an __init method for it. The subclass will automatically use the __init of the superclass.

Contributing

Install Rojo and then run the following commands:

$ rojo build -o place.rbxlx
$ rojo serve

Open the newly generated place file and start the Rojo plugin.

From here you can modify anything under src/ and your changes will be synced in.

When you're ready to test, simply press F5 to play the game.