Assertion Failed! Stack Traceback:...

Solar2D Lua Language
#1

I’m new and I’m just playing around with game development. Been staring at this for hours trying to figure out what I’m doing wrong but I just don’t see it.

   Corona_Runtime_Error.jpg

All I want to happen is when the jumper is tapped, he moves up on the y axis. I keep getting different errors when I move things around but here are how things are currently.

 – usuals

display.setStatusBar(display.HiddenStatusBar)

local centerX = display.contentCenterX

local centerY = display.contentCenterY

– forward references

local jumper

– preload audio

local function createPlayScreen( )

    local background = display.newImage(“snowBackground.jpg”)

        background.yScale = 1.3

        background.xScale = 1.3        

        background.x = centerX

        background.y = centerY

        background.alpha = 0

            transition.to ( background, { time=2000, alpha=1 } )

    jumper = display.newImage(“jumper.png”)

        jumper.xScale = .65

        jumper.yScale = .65

        jumper.x = centerX

        jumper.y = display.contentHeight +100

            transition.to ( jumper, { time=2000, y=display.contentHeight - 100} )

        

    local title = display.newImage(“titleG.png”)

        title.x = centerX

        title.xScale = .65

        

        title.alpha = 0

            

            transition.to ( title, { time=2000, alpha=1 } )

end

local function jumperTap( )

    

    jumper:addEventListener (  “tap”,  jumperJump  )

    

end    

local function startGame( )

end

local function planetDamage( )

end

local function hitPlanet( )

end

local function jumperJump(event)

    

    transition.to(  jumper,  { time=500,  y=100 }  )

    

end

createPlayScreen( )

jumperTap( )

Any and all help is greatly appreciated.

#2

unfortunately the assertion statement doesn’t give you any reasonable feedback so you know what the issue is, e.g. “addEventListener: event listener must be a function”.

but i’d look at the the addEventListener line here:

local function jumperTap( ) jumper:addEventListener ( "tap", jumperJump ) end

you might want to try and forward-declare ‘jumperJump’ as you have done for ‘jumper’.

-- at top of module local jumperJump -- anywhere else jumperJump = function( event ) ... rest end

cheers, dmc

#3

The assertion message is telling you there is a problem in the function starting on line 45 and the EventListener. “jumperJump” is undefined because it doesn’t exist yet. Adding the forward reference should fix the problem.

#4

unfortunately the assertion statement doesn’t give you any reasonable feedback so you know what the issue is, e.g. “addEventListener: event listener must be a function”.

but i’d look at the the addEventListener line here:

local function jumperTap( ) jumper:addEventListener ( "tap", jumperJump ) end

you might want to try and forward-declare ‘jumperJump’ as you have done for ‘jumper’.

-- at top of module local jumperJump -- anywhere else jumperJump = function( event ) ... rest end

cheers, dmc

#5

The assertion message is telling you there is a problem in the function starting on line 45 and the EventListener. “jumperJump” is undefined because it doesn’t exist yet. Adding the forward reference should fix the problem.