LUA questions

[Bonci]

How do you guys know method and event names? Is there any documentation or is it reverse engineering?

I'm trying to find a mod which deletes units to see how the function is called, does anyone know?

Thanks!

 

[Gedemon]

see https://forums.civfanatics.com/threads/lua-objects.601146/

and to delete an unit:

pPlayer:GetUnits():Destroy(pUnit)

 

[Bonci]

Nice, thank you!
Sorry if i ask many questions, but I think that if I understand some things I'll be able to work things out on my own.
I have some code like this:

function OnPlayerTurnActivated(iPlayer,bFirst)
if (iPlayer < PlayerManager.GetWasEverAliveMajorsCount()) then
...
end
end
Events.PlayerTurnActivated.Add(OnPlayerTurnActivated)

because I want the following code to be applied only to major civs, not city states.

But when I pass the turn I get this:

Runtime Error: C:/path/file.lua:108: attempt to index a nil value
stack traceback:
    C:/path/file.lua:108: in function 'OnPlayerTurnActivated'
    [C]: in function 'func'
    [C]: in function '(anonymous)'

108 is the second line, not the declaration of the function.

How can iPlayer be nil?

 

[Gedemon]

It's not the id, else you'd get a message about using < with nil.

And PlayerManager should be avaible in all context IIRC.

 

[LeeS]

The first argument passed for PlayerTurnActivated will be the ID # of the player from the Players table.

function PlayerTurnBegin(iPlayer)
	PrintToLog("[PlayerTurnBegin] iPlayer is " .. tostring(iPlayer))
	if iPlayer == 63 then
		PrintToLog("[PlayerTurnBegin] Player # " .. iPlayer .. " (Barbarians) cannot normally have cities")
		return
	end
	local pPlayer = Players[iPlayer]
	local pCities = pPlayer:GetCities();
	if pCities:GetCount() > 0 then
		PrintToLog("[PlayerTurnBegin] Player # " .. iPlayer .. " has some cities")
		for i, pCity in pCities:Members() do
			SetCityUnlockerStatuses(pCity)
		end
	else
		PrintToLog("[PlayerTurnBegin] Player # " .. iPlayer .. " has no cities")
	end
end
Events.PlayerTurnActivated.Add(PlayerTurnBegin)

So try something like

local pPlayer = Players[iPlayer]
if pPlayer:IsMajor() then
     --do stuff
end

 

[LeeS]

the problem with this:

if (iPlayer < PlayerManager.GetWasEverAliveMajorsCount()) then

as a method to sort out whether the player is a major civ or not is that PlayerManager.GetWasEverAliveMajorsCount() only gives you an integer number for the amount of major players that were ever alive during the course of the game. But the player ID#s passed to the event hooks start at '0' for the human player. If only the human player was ever alive as a major player in the game, this would print "1" in the lua log:

print(PlayerManager.GetWasEverAliveMajorsCount())

From the testing I remember doing in civ6 for these sorts of things, civ6 works differently than civ5, and the 1st City-State in such a one-major-player game would get assigned player ID# "1". So the 1st city-state will always be seen as meeting this condition:

if (iPlayer < PlayerManager.GetWasEverAliveMajorsCount()) then

Far better to get the player object via

local pPlayer = Players[iPlayer]

and then asking whether that currently-being-processed player is a Major Civ via

if pPlayer:IsMajor() then

 

[Bonci]

if pPlayer:IsMajor() then

It works!

Thank you both for the help!

 

[LeeS]

eeesh. I just realised I typed { instead of [ in one place in my previous post, but it sounds like you caught that already. I fixed my previous post.

It was correct in Post #5 but I mis-typed in Post #6.

 

[Bonci]

Now I'm trying to delete all the units of a player

local aPlayerUnits = pPlayer:GetUnits();
for loop,iPlayerUnit in ipairs(aPlayerUnits) do
      print ("unit: "..tostring(iPlayerUnit))
      local pPlayerUnit = player:GetUnits():FindID(iPlayerUnit);
      pPlayer:GetUnits():Destroy(pPlayerUnit)
end

But the code never goes inside the loop, as if there were no units...but there are in game.
No errors though.

I also tried

local aPlayerUnits = pPlayer:GetUnits():Members();

but then i get an error saying aPlayerUnits is a function and not a table.

 

[LeeS]

1. Your player objects are not the same.
   

   player:GetUnits():FindID(iPlayerUnit);
   pPlayer:GetUnits():Destroy(pPlayerUnit)

2. This is an example of looking through a player's units and recording the XY grid position of the first settler found in the player's units:

   local pPlayerUnits = pPlayer:GetUnits()
   local iStartingX, iStartingY = -1,-1
   for i, pUnit in pPlayerUnits:Members() do
   	if "LOC_UNIT_SETTLER_NAME" == UnitManager.GetTypeName(pUnit) then
   		print("Settler found by the UnitManager.GetTypeName(pUnit) method")
   		iStartingX, iStartingY = pUnit:GetX(), pUnit:GetY()
   		break
   	end
   end

3. pPlayerUnits:Members() is structured as it if were an lua table. Never destroy items within the table of a player's units, for example, while in the midst of iterating through the items within the table. Doing so will almost always result in items within the list not being processed because the removal of a previous item causes a de-synch in the item #s (the "i" values in this case).
4. I would try as follows:

   local pPlayerUnits = pPlayer:GetUnits()
   local tUnitsToDestroy = {}
   for i,pUnitToDestroy in pPlayerUnits:Members() do
   	table.insert(tUnitsToDestroy, pUnitToDestroy)
   end
   for iKey,pUnitToDestroy in pairs(tUnitsToDestroy) do
   	pPlayerUnits:Destroy(pUnitToDestroy)
   end
   tUnitsToDestroy = {}

   This should work assuming Destroy(Unit) works as stated and does not require additional info (the methodology works in civ5 lua except that civ5 uses Kill()) because when you are running through the list of items in table tUnitsToDestroy you are not actually removing anything listed in table tUnitsToDestroy, strange as it may seem.
5. Note that if you are attempting the code within a UI context rather than as part of a GameplayScripts,

   Player:GetUnits():Destroy(Unit)

   appears only to be available within a GameplayScript context.

 

[Bonci]

Ok, understood
On the line

pPlayerUnits:Destroy(pUnitToDestroy)

I get "function expected instead of nil" do you think there is some other parameter that needs to be passed?

Those errors are not very clear

 

[LeeS]

it's an indication that

pPlayer:GetUnits():  Destroy(pUnitToDestroy)

isn't actually hooked up to anything as yet within GameplayScripts. I've run into this for a few other items in Gedemon's list of lua objects.

 

[Gleb Bazov]

Since the time this was posted, something must have been updated in the base game files, because the following simple function:

function OnWarriorAddedToMap( playerID : number, unitID : number )
    local pPlayer = Players[ playerID ]
    if pPlayer ~= nil then
        local pUnit = pPlayer:GetUnits():FindID(unitID)
        if pUnit:GetType() == GameInfo.Units["UNIT_WARRIOR"].Index then
            pPlayer:GetUnits():Destroy(pUnit)
        end
    end
end
Events.UnitAddedToMap.Add(OnWarriorAddedToMap);

works without any issues. Unless I am misunderstanding the actual mechanic you are trying to achieve here. If so, my apologies. However, if the functions has been turned on since, this is welcome news, as it indicates that other previously-dormant functions may have also been activated.

 

[Bonci]

Oh thank you for the update, I will check if it works now in my code!