Modding Help Checking my LUA and NPC spawner.

Hello there. Had a go at modifying the in-game monster spawner to work with NPCs. Could someone please give this a look-over and see if I did it correctly? I haven't had time to test it out yet, but I would like to get it as correct as possible before beginning testing. With any luck, I want it to spawn NPCs in much the same way as the monster spawner works - being able to define NPC type, race, level, and other parameters on the fly.

The last bit of the LUA is the main bit which I changed.

Thanks in advance.

The object:

Code:

{
  "objectName" : "extranpcspawner",
  "colonyTags" : ["misc"],
  "rarity" : "Common",
  "description" : "Spawns npcs in a variety of configurable ways.",
  "shortdescription" : "Npc Spawner",
  "race" : "human",
  "printable" : false,
  "category" : "spawner",
  "price" : 133,

  "inventoryIcon" : "extranpcspawnericon.png",
  "orientations" : [
    {
      "image" : "extranpcspawner.png",
      "imagePosition" : [-8, 0],

      "spaceScan" : 0.1,
      "anchors" : [ "bottom" ]
    }
  ],

  "scripts" : [ "/objects/wired/extranpcspawner/extranpcspawner.lua" ],
  "scriptDelta" : 10,

  "inputNodes" : [ [-1, 0] ],

  "spawner" : {
    "npcTypes" : ["hostile"], //type of npc to spawn (random from list)
    "npcSpecies" : [ "apex", "avian", "floran", "glitch", "human", "hylotl", "novakid" ], //species of NPC to spawn.
    "npcLevel" : [1, 10], //level of npc to spawn (random within range, or leave blank for world threat level)
    "npcParams" : { //additional parameters of spawned npc
      "aggressive" : true
    },
    "position" : [0, 1], //relative position to spawn at
    "positionVariance" : [10, 0], //[x,y] size of randomized spawn area, centered on position
    "frequency" : [5.0, 5.0], //cooldown time between spawns (random within range)
    "stock" : 5, //total number of spawns, -1 for infinite
    "trigger" : null, //options include "wire", "interact", "break", null (periodic)
    "outOfSight" : false //only spawn where the player can't see
  },

  "smashOnBreak" : true
}

The LUA:

Code:

require "/scripts/util.lua"

function init()
  self = config.getParameter("spawner")
  if not self then
    sb.logInfo("npc spawner at %s is missing configuration! Prepare for some serious Lua errors!", object.position())
    return
  end

  object.setInteractive(self.trigger == "interact")
  self.position = object.toAbsolutePosition(self.position)
  storage.cooldown = storage.cooldown or util.randomInRange(self.frequency or {0, 0})
  storage.stock = storage.stock or self.stock
end

function onInteraction(args)
  if self.trigger == "interact" then
    spawn()
  end
end

function update(dt)
  if storage.stock ~= 0 then
    if storage.cooldown > 0 then storage.cooldown = storage.cooldown - dt end

    if storage.cooldown <= 0 and ((not self.trigger) or (self.trigger == "wire" and object.getInputNodeLevel(0))) then
      spawn()
      storage.cooldown = util.randomInRange(self.frequency or {0, 0})
    end
  end
end

function die()
  if self.trigger == "break" then
    for i = 1, storage.stock do
      spawn()
    end
  end
end

function spawn()
  local attempts = 10
  while attempts > 0 do
    local spawnPosition = {}
    for i,val in ipairs(self.positionVariance) do
      if val == 0 then
        spawnPosition[i] = self.position[i]
      else
        spawnPosition[i] = self.position[i] + math.random(val) - (val / 2)
      end
    end

    if not self.outOfSight or not world.isVisibleToPlayer({spawnPosition[1] - 3, spawnPosition[2] - 3, spawnPosition[1] + 3, spawnPosition[2] + 3}) then
      local npcType = util.randomFromList(self.npcTypes)
      local npcSpecies = util.randomFromList(self.npcSpecies)     
      self.npcParams.level = self.npcLevel and util.randomInRange(self.npcLevel) or world.threatLevel()

      local npcId = world.spawnNpc(spawnPosition, npcSpecies, npcType, self.npcParams.level, nil, npcParameter)
      if npcId ~= 0 then
        storage.stock = storage.stock - 1
        return
      end
    end

    attempts = attempts - 1
  end
end