CODEWITHSUNDEEP
ooplua
chown
chown

Reputation: 111

How to export, then access exported methods in Lua

I have a file, display.lua in which I have code to load some resources.

----display.lua
Resources = {}

function Resources:new(rootdir)
  local newObj = {image = {}, audio = {}, root = ""}
  newObj.root = rootdir
  return setmetatable(newObj, self)
end

function Resources:getSpriteSheet(name)
    --- etc etc etc
end

and then I have a game variable I use to store gamestate, this is within another file game.lua.

---game.lua
require "display.lua"

function Game:new()
  local newObj = {mode = "", map = {}, player = {}, resources = {}}
  self.__index = self
  return setmetatable(newObj, self)
end

function Game:init()
  self.resources = Resources:new("/home/example/etc/game/")
  local spriteSheet = self.resources:getSpriteSheet("spritesheet.png")
end

I have access to the resources code via use of require. My issue is that within Game:init() I can't access Resources:getSpriteSheet(), the lua interpreter complains of "attempt to call method (getSpriteSheet) a nil value"

I assume here I would have to export the methods in Resources but I don't know how I'd go about doing this, as I'm quite new to Lua.

Upvotes: 5

Views: 9310

Answers (1)

Paul Kulchenko
Paul Kulchenko

Reputation: 26754

I think you want return setmetatable(newObj, {__index = self}) instead of return setmetatable(newObj, self).

Also, require "display.lua" should probably be require "display" and game.lua should have Game = {} somewhere at the top. With these changes your example works for me.

Upvotes: 3

Related Questions