My background prior to about 6 weeks ago was Adobe Flash back to the Flash 3 and the Macromedia days. It was very common for some of the swf apps I wrote to use dynamic variables for repetative tasks. In ActionScript it would be something like this:
num = 1;
eval("box" + num) == 10
The variable box1 is now equal to 10
or in a dynamic movieclip
num = 1;
MovieClip[num].gotoAndStop(10)
MovieClip1 is now on frame 10
Fast forward to Lua. I was looking for the same technique in my Corona app. I bought the “Programming in Lua” 2nd edition and it talks about how to do this on p. 129. I followed this and my function looks something like this:
-- Swap ability function
local function swapAbilities(stat)
local ability1 = \_G[swapValue1]
\_G[swapValue1] = \_G[stat]
\_G[stat] = ability1
\_G[stat.."\_object"].text = \_G[stat]
\_G[swapValue1.."\_object"].text = \_G[swapValue1]
swapValue1 = nil
end
where “swapValue1” and “stat” are Global variables.
(I know this might not be the best way to do this but bear with me…
Using just “main.lua” this works like a CHAMP!! but, the moment I use this code in another module, it fails! Even if I declare the variables in the same module. I have checked in the terminal and everything is there, i.e. the variables exist but using _G to dynamically work with the variables fails in the external modules.
Any ideas? (I’m sure it’s Operator Error)
Thanks!
Brian [import]uid: 71093 topic_id: 14545 reply_id: 314545[/import]
Brilliant!! I will incorporate this into the function. I will test your local theory on the function as well. There are probably much better ways to do this but I think I will stumble on and try to work it through. If anything it might teach me a few things.
Thanks for taking the time to help!
Brian [import]uid: 71093 topic_id: 14545 reply_id: 53816[/import]
Does removing the word “Local” make the function Global? If so, it didn’t work. It’s almost like the “_G” is for some reason not available to the external module. Is that possible?
\_G[swapValue1],\_G[stat] = \_G[stat],\_G[swapValue1]
-- Where swapValue1 = "dex" and stat = "str", this FAILS
str,dex = dex,str -- These are global variables, work fine.
Though it doesn’t fail using the “main.lua” and no external modules.
Scratching Head in Florida
Brian [import]uid: 71093 topic_id: 14545 reply_id: 53824[/import]
If you are using the Lua module system, I think there are visibility things that change the environment to insulate changes to _G to not contaminate your main program.
module(…, package.seeall) has something to do with this.
in my external modules. I borrowed some code from the iDeveloper blog maintained by Beebe Games. It is a simple method for managing scenes and works quite nicely! Once I separated my code from a single to multiple scenes it broke on this part and this part only. I can avoid using the _G if it might cause a problem.
I read the article and it caused my brain to hurt but, I get the gist.
Thanks for the help and I hope they get this solved soon!
Brian [import]uid: 71093 topic_id: 14545 reply_id: 53903[/import]
Think of it again, and you will find that is *could* be easier and if you model it well, you could use arrays instead of mucking around with the _G variables, you can have a read of this article
