issues when passing parameter values between screens

Getting Started Newbie Questions
#1

Hi,

     I am having problems with a specific value that is passed to the screen from the calling screen. The value comes through fine initially, then disappears for no apparent reason, resulting in “error”. please help.

This code was working fine before and I am having issues because I have made changes introducing “levels”  and passing appropriate values based on the level chosen by the user.

I have tried 3 options, 1. using persistent storyboard variables 2. passing params between screens and 3. even setting up a local variable a1=1.

The value gets passed on properly but somehow the values for a1 disappears by the time I define my button and try to set the text value, based on a data array. I checked memory usage and it is about .5 MB. Is there a limitation as to how many variables can be active in memory in corona?

-thanks

==================================

function scene:createScene( event )

    local screenGroup = self.view

       local params = event.params

       coinscnt = storyboard.state.coins

       seqno = storyboard.state.seqno

       a2 = params.p_seqno  --a2 gets value 1 properly here

       print( "inside main scene " … collectgarbage(“count”)/1000 … “MB”)

    

     if storyboard.state.level == 1 then 

      wordsData = table.copy( wordsData1) 

      --print("w1: ", wordsData[seqno].w1) 

     end

     if storyboard.state.level == 2 then 

      wordsData = table.copy( wordsData2)  

     end

    

     local y = 1

     while (y < 11) do

       print("wordsdata: ", wordsData[y].name, wordsData[y].w1 ) --data array has proper values

       y = (y+1)

     end

    

     print("1 a2 val: ", a2)  --a2 value good until here

    

background = display.newImageRect( “bgblue3.png”, 640, 960 ) 

background.x = display.contentCenterX;

background.y = display.contentCenterY;

screenGroup:insert( background )     

backb = display.newImageRect( “back1.png”, 30, 30 ) 

backb.x = 30;

backb.y = 20;

puzzno = display.newText(a1, 80  , 20, “verdana”, 16)

puzzno.x = 80

puzzno.y =  20

puzzno:setTextColor(74, 74, 74)    

   

moreb = display.newImageRect( “more1.png”, 30, 30 ) 

moreb.x = 280;

moreb.y = 20;

  

imgcoins = display.newImageRect( “coins.png”, 30, 30 ) 

imgcoins.x = centerX - 20;

imgcoins.y = 20;  

coinsText = display.newText(coinscnt, centerX+20  , 8, “verdana”, 16)

coinsText:setTextColor(74, 74, 74)    

screenGroup:insert( backb ) 

screenGroup:insert( puzzno ) 

screenGroup:insert( moreb ) 

screenGroup:insert( imgcoins ) 

screenGroup:insert( coinsText ) 

myButton1 = widget.newButton

{

   left = qn1Xpos,

   top = qn1Ypos,

   width = ansbutwidth,

   height = ansbutht,

   label = “Default”,

   labelAlign = “center”,

   font = “Verdana”,

   fontSize = 18,

   textonly = true,

   labelColor = { default = {40,40,40}, over = {255,255,255} },

   onEvent = onButtonEvent

}

myButton1.baseLabel = “Default”

myButton1.setReferencePoint = (display.CenterReferencePoint)

print("a2 before setting mybutt: ", a2, wordsData[1].w1) --a2 value is nil causing error in the next line

–myButton1:setLabel( wordsData[a2].w1  ) – this works. array has proper values

myButton1:setLabel( wordsData[a2].w1  ) --error due to a2 being nil

debug results:

mem usage: 0.574724609375MB

2013-08-31 19:15:36.314 Corona Simulator[212:707] wordsdata:     Lion King Characters    Simba

2013-08-31 19:15:36.315 Corona Simulator[212:707] 1 a2 val:     1

2013-08-31 19:15:36.334 Corona Simulator[212:707] a2 before setting mybutt:     Dalmatian

2013-08-31 19:15:36.340 Corona Simulator[212:707] Runtime error

/Applications/fourwords1Group/scrMain.lua:365: attempt to index field ‘?’ (a nil value)

stack traceback:

==============================================================

#2

The only thing I see is that a2 appears to be a global variable and something might be trashing it.  Normally I would expect it to print “nil” for at if it’s nil, since there is a value after it.  Is there any chance that a2 is actually the value “Dalmation” and wordsdata[“Dalmation”] is nil?  That would make that error make more sense. Though I don’t see where that’s happening.

#3

Rob,

        Thanks for looking into this. The problem is solved. The problem was because of the p_seqno parameter passed from the previous screen. a2 = params.p_seqno

I retrieve the game data for all the “levels” and store it in a lua array and pass the appropriate values for the level chosen by the user, from the array. For some reason this was causing the problem, though the stored and passed value was numeric. The problem went away when I did a tonumber(array value), before passing it. I have since removed a2 and using a local variable to capture the “p_seqno”.

-thanks

#4

The only thing I see is that a2 appears to be a global variable and something might be trashing it.  Normally I would expect it to print “nil” for at if it’s nil, since there is a value after it.  Is there any chance that a2 is actually the value “Dalmation” and wordsdata[“Dalmation”] is nil?  That would make that error make more sense. Though I don’t see where that’s happening.

#5

Rob,

        Thanks for looking into this. The problem is solved. The problem was because of the p_seqno parameter passed from the previous screen. a2 = params.p_seqno

I retrieve the game data for all the “levels” and store it in a lua array and pass the appropriate values for the level chosen by the user, from the array. For some reason this was causing the problem, though the stored and passed value was numeric. The problem went away when I did a tonumber(array value), before passing it. I have since removed a2 and using a local variable to capture the “p_seqno”.

-thanks