nil value by acces to global variable

[derbobo]

Hello,
I have problem with a mod i try to make , beacaue everytime when i try to run a function called add_newelementextension i´ll get this error message:"control.lua:23: attempt to index field 'taxiextension' (a nil value)"

here is my code:

Code: Select all

require "util"
require "defines"
script.on_load(function()
if global.taxiextension ==nil then 
global.taxiextension={}
end

 
end)

function add_newelementextension(name)
local taxi
		for chunk in game.get_surface(1).get_chunks() do
			local entities = game.get_surface(1).find_entities_filtered{backer_name=name, area={{chunk.x*32, chunk.y*32}, {(chunk.x+1)*32, (chunk.y+1)*32}}}
				for _, entity in pairs(entities) do
					if entity.name == "taxi" then
					 taxi=entity
					 end
				end
		end
		if taxi~=nil then 
			local a={}
			for i=0, global.taxiextension.getn, 1 do
				if i ~=0 then
				a[i]= global.taxiextension[i]
				end
			end
			local t =global.taxiextension.getn + 1
			a[t]={key=taxi.backer_name,val ={caller=player,available=true}}
		end
end

[Adil]

On_load is called on savegame load only.
Add a print statement to a line 4 for example and you'll see that nothing is printed when you start a new game.
Also these: why don't you use more these of these: "_" in compound names?

[DedlySpyder]

Also these: why don't you use these in compound names "_"?

Or use camelCaseNames

[Adil]

But undrescores are Factorio devteam standard

Also, getn is deprecated lua has # now:

Code: Select all

for i=1, #global.taxiextension do

And by default tables are indexed from 1.

[derbobo]

And by default tables are indexed from 1.

I know but when the table is empty the for statement will never stop

[Adil]

What?

[ArderBlackard]

I know but when the table is empty the for statement will never stop

I swear it will