Class

Based on game build 714014 | Last updated: 2026-03-21

Overview

class.lua implements a foundational object-oriented programming system for Don't Starve Together. It provides class creation with inheritance support, property getter/setter mechanisms, read-only property protection, and optional instance tracking for debugging. This utility is used throughout the codebase to define structured data types, components, stategraphs, and other systems that benefit from encapsulation and inheritance.

Usage example

local Class = require("class")

local MyClass = Class(function(self, name, value)
    self.name = name
    self.value = value
end)

local instance = MyClass("test", 42)
print(instance.name) -- "test"
print(instance.value) -- 42

-- With property setters
local MyPropClass = Class(nil, function(self) self._count = 0 end, {
    count = function(self, val, old)
        print("Count changed from "..tostring(old).." to "..tostring(val))
    end
})

Dependencies & tags

Components used: None identified Tags: None identified

Properties

Property	Type	Default Value	Description
_base	table	nil	Reference to parent class when using inheritance.
_ctor	function	nil	Constructor function called on instance creation.
is_a	function	_is_a	Method to check if instance is descendant of a class.
is_class	function	_is_class	Method to check if table is a class definition.
is_instance	function	function	Method to check if object is an instance of this class.

Main functions

Class(base, _ctor, props)

• Description: Creates a new class with optional inheritance, constructor, and property handlers. This is the primary entry point for defining classes in DST.
• Parameters:
  • base (table or function) - Parent class to inherit from, or constructor function if no inheritance.
  • _ctor (function) - Constructor called with self as first argument when creating instances.
  • props (table) - Optional table of property names mapped to setter functions for reactive property changes.
• Returns: A class table that can be called to create instances.
• Error states: If props is provided but the class system is not properly initialized, property setters may fail.

makereadonly(t, k)

• Description: Converts an existing property into a read-only property that cannot be modified after initialization.
• Parameters:
  • t (table) - The class or instance table.
  • k (string) - The property key to make read-only.
• Returns: Nothing.
• Error states: Asserts if the class does not support read-only properties (no props table was defined).

addsetter(t, k, fn)

• Description: Adds or updates a setter function for a property, enabling reactive behavior when the property value changes.
• Parameters:
  • t (table) - The class or instance table.
  • k (string) - The property key.
  • fn (function) - Setter function called with (table, new_value, old_value) when property changes.
• Returns: Nothing.
• Error states: Asserts if the class does not support property setters.

removesetter(t, k)

• Description: Removes a setter function from a property, converting it back to a regular field.
• Parameters:
  • t (table) - The class or instance table.
  • k (string) - The property key to remove the setter from.
• Returns: Nothing.

_is_a(self, klass)

• Description: Internal function to check if an object is a descendant of a given class through the inheritance chain.
• Parameters:
  • self (table) - The instance to check.
  • klass (table) - The class to test against.
• Returns: true if self inherits from klass, false otherwise.

_is_class(self)

• Description: Internal function to determine if a table is a class definition rather than an instance.
• Parameters:
  • self (table) - The table to check.
• Returns: true if the table is a class, false if it is an instance.

ReloadedClass(mt)

• Description: Removes a class from the ClassRegistry when hot-reloading code, preventing memory leaks from stale references.
• Parameters:
  • mt (table) - The metatable of the class to remove.
• Returns: Nothing.

HandleClassInstanceTracking()

• Description: Debug function that periodically prints the top 10 most instantiated classes when TrackClassInstances is enabled. Used for memory profiling and leak detection.
• Parameters: None.
• Returns: Nothing.
• Error states: Only functions when TrackClassInstances is set to true and CWD is defined.

Events & listeners

Not applicable