Lua class

A library to add support for OOP on Lua with a really nice and elegant style. This was created and tested by me on a personal project in a videogame called "Multi Theft Auto", however it may be useful for someone else someday, as it should work anywhere with Lua <3, if you like it feel free to give it a star and follow me please.

How to use?

Just download the include.lua file and include it to your project, it will work in any project that uses lua. This library was designed and tested on Lua 5.1

• Note: For Lua 5.3 you'll have to change unpack function for table.unpack.

Create your first class

Its pretty easy, as said it adds support to create classes using an elegant syntax

class 'HelloWorld' {
  constructor = function(self, arg1, arg2, ...)
  
  end,
  
  destructor = function(self)
  
  end,
  
  greet = function(self)
    print('Hello world!');
  end,
}

Inheritance

The library supports class single inheritance and multiple inheritance preserving a nice style.

Single class inheritance

class 'Gamemode' {
  constructor = function(self)
    self.players = {};
    self.map = false;
    self.state = GamemodeState.NotRunning;
  end,
  
  destructor = function(self)
    -- Do something with players I guess
  end,
  
  unloadMapForPlayer = function(self, player)
    player:triggerClientEvent('unloadMap');
  end,
}

class 'RaceGamemode' (Gamemode) {
  constructor = function(self)
    self.vehicles = {};
    self.checkpoints = {};
  end,
  
  destructor = function(self)
    self:unloadPlayers();
  end,
  
  unloadPlayers = function(self)
    for _, player in pairs(self.players) do
      self:unloadMapForPlayer(player);
      self:destroyPlayerVehicle(player);
    end
  end,
  
  destroyPlayerVehicle = function(self, player)
    self.vehicles[player]:destroy();
    self.vehicles[player] = nil;
  end,
}

Multiple class inheritance

include 'gamemodes.lua'

class 'TeamGamemode' {
  constructor = function(self)
    self.teamA = Team(...)
    self.teamB = Team(...)
  end,
  
  assignPlayerTeam = function(self, player)
    local randomTeam = math.random(0, 1)
    if (randomTeam == 0) then
      player:setTeam(self.teamA);
    else
      player:setTeam(self.teamB);
    end
  end,
}

class 'Deathmatch' (Gamemode, TeamGamemode) {
  constructor = function(self, arguments)
    self.settings = arguments;
  end,

  onPlayerJoin = function(self, player)
    self:assignPlayerTeam(player);
    self:checkGameState();
  end,
  
  checkGameState = function(self)
    if (self:getAlivePlayersCount() < 1) then
      self:startNextRound();
    end
  end,
}

Creating objects/instances

Just call your class name like a normal function and you're ready to go!

include 'deathmatch.lua'

g_Deathmatch = Deathmatch { randomMaps = true, maxPlayers = 16, pingLimit = 280 };
g_Race = RaceGamemode();

Partial classes

Isn't a great practice at all but sometimes you may want to keep a specific-purpose class with its related topic on a file. Lets supose you have a class for x functionality and it has an "Utils" class, you may want to keep that part of the code on the same file, also you have another class for Utils for your y functionality. In Lua the reasonable behaviour would be to overwrite existing class for the one of y functionality. Using this library you'll be able to have both and they'll be merged into a single class; Example:

-- file mapmanager.lua
class 'MapManager' {
  -- ...
}

class 'Utils' {
  getFileHash = function(path)
    -- ...
  end,
}

-- file scriptloader.lua
class 'ScriptLoader' {
  -- ...
}

class 'Utils' {
  generateEmptyEnvironment = function(self)
    -- ...
  end,
}

-- Ending Utils class
class 'Utils' {
  getFileHash = function(path)
    -- ...
  end,
  
  generateEmptyEnvironment = function(self)
    -- ...
  end,
}