Accessing a variable in another lua file

squeegene · October 28, 2016, 7:01am

Hi, I’m a beginner to Lua! Trying to get an app up and running really quickly.

I tried to make a sliding panel as in this example:

https://coronalabs.com/blog/2014/04/08/widgets-creating-a-sliding-panel/

And everything worked fine when it was all in one script. However, I put the following lines in another script called “createPanel.lua”:

local widget = require("widget") local function panelTransDone( target ) &nbsp; &nbsp; --native.showAlert( "Panel", "Complete", { "Okay" } ) &nbsp; &nbsp; if ( target.completeState ) then &nbsp; &nbsp; &nbsp; print( "PANEL STATE IS: "..target.completeState ) &nbsp; &nbsp; end &nbsp; end panel = widget.newPanel{ &nbsp; location = "left", &nbsp; onComplete = panelTransDone, &nbsp; width = display.contentWidth \* 0.5, &nbsp; height = display.contentHeight, &nbsp; speed = 250, &nbsp; inEasing = easing.outBack, &nbsp; outEasing = easing.outCubic } panel.background = display.newRect( 0, 0, panel.width, panel.height ) panel.background:setFillColor( 0, 0.25, 0.5 ) panel:insert( panel.background ) panel.title = display.newText( "Menu", 0, 0, native.systemFontBold, 18 ) panel.title:setFillColor( 1, 1, 1 ) panel:insert( panel.title )

And in my original script I say

local createPanel = require("scripts.createPanel")

I get no errors, but when I call panel:show() in my original script, it doesn’t work. I know the createPanel() script is being called because I get the alert from

native.showAlert( "Panel", "Complete", { "Okay" } )

so I’m a bit confused.

On a side note, does anybody know if there’s a better way to debug things? Should I just be printing things out to the console a lot?

rob · October 28, 2016, 6:06pm

Is that all the code for createPanel.lua?

Can you also post your code where you’re trying to show the panel?

Rob

squeegene · October 28, 2016, 6:57pm

Yep!

--Required APIs and Libraries local composer = require( "composer" ) local display = require("display") local widget = require( "widget" ) local createPanel = require( "scripts.createPanel" ) --This is where I access the other script --Create new scene object local scene = composer.newScene() -- "scene:create()" function scene:create( event ) &nbsp; &nbsp;local sceneGroup = self.view &nbsp; &nbsp;local background = display.newRect( &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; display.contentWidth/2, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; display.contentHeight/2, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; display.contentWidth, &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; display.contentHeight); &nbsp; &nbsp;background:setFillColor(225/255, 225/255, 225/255) &nbsp; &nbsp;local function handleLeftButton( event ) &nbsp; &nbsp; &nbsp; if ( event.phase == "ended" ) then &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;panel:show() -- I try to access the panel here &nbsp; &nbsp; &nbsp; end &nbsp; &nbsp; &nbsp; return true &nbsp; &nbsp;end &nbsp; &nbsp;local function handleRightButton( event ) &nbsp; &nbsp; &nbsp; if ( event.phase == "ended" ) then &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;-- do stuff &nbsp; &nbsp; &nbsp; end &nbsp; &nbsp; &nbsp; return true &nbsp; &nbsp;end &nbsp; &nbsp;local leftButton = { &nbsp; &nbsp; &nbsp; onEvent = handleLeftButton, &nbsp; &nbsp; &nbsp; width = 60, &nbsp; &nbsp; &nbsp; height = 34, &nbsp; &nbsp; &nbsp; defaultFile = "images/ic\_menu\_black\_24px.svg", &nbsp; &nbsp; &nbsp; overFile = "images/ic\_menu\_black\_24px.svg", &nbsp; &nbsp; &nbsp; isBackButton = false &nbsp; &nbsp;} &nbsp; &nbsp;local rightButton = { &nbsp; &nbsp; &nbsp; onEvent = handleRightButton, &nbsp; &nbsp; &nbsp; label = "ADD", &nbsp; &nbsp; &nbsp; labelColor = { default = &nbsp;{0, 0, 0}, over = { 0.5, 0.5, 0.5} }, &nbsp; &nbsp; &nbsp; font = "ElegantLight.ttf", &nbsp; &nbsp; &nbsp; isBackButton = false &nbsp; &nbsp;} &nbsp; &nbsp;local navBar = widget.newNavigationBar({ &nbsp; &nbsp; &nbsp; title = "FLARE", &nbsp; &nbsp; &nbsp; backgroundColor = { 1, 1, 1 }, &nbsp; &nbsp; &nbsp; titleColor = {0,0,0}, &nbsp; &nbsp; &nbsp; font = "ElegantLight.ttf", &nbsp; &nbsp; &nbsp; leftButton = leftButton, &nbsp; &nbsp; &nbsp; rightButton = rightButton, &nbsp; &nbsp; &nbsp; includeStatusBar = true &nbsp; &nbsp;}) &nbsp; panel = createPanel.createPanel() -- panel = createPanel:createPanel() --Not sure if I'm doing this right, or if this has to be done at all since I've already "included" the other script --Everything past this point is extraneous end -- "scene:show()" function scene:show( event ) &nbsp; &nbsp;local sceneGroup = self.view &nbsp; &nbsp;local phase = event.phase &nbsp; &nbsp;if ( phase == "will" ) then &nbsp; &nbsp; &nbsp; -- Called when the scene is still off screen (but is about to come on screen). &nbsp; &nbsp;elseif ( phase == "did" ) then &nbsp; &nbsp; &nbsp; -- Called when the scene is now on screen. &nbsp; &nbsp; &nbsp; -- Insert code here to make the scene come alive. &nbsp; &nbsp; &nbsp; -- Example: start timers, begin animation, play audio, etc. &nbsp; &nbsp;end end -- "scene:hide()" function scene:hide( event ) &nbsp; &nbsp;local sceneGroup = self.view &nbsp; &nbsp;local phase = event.phase &nbsp; &nbsp;if ( phase == "will" ) then &nbsp; &nbsp; &nbsp; -- Called when the scene is on screen (but is about to go off screen). &nbsp; &nbsp; &nbsp; -- Insert code here to "pause" the scene. &nbsp; &nbsp; &nbsp; -- Example: stop timers, stop animation, stop audio, etc. &nbsp; &nbsp;elseif ( phase == "did" ) then &nbsp; &nbsp; &nbsp; -- Called immediately after scene goes off screen. &nbsp; &nbsp;end end -- "scene:destroy()" function scene:destroy( event ) &nbsp; &nbsp;local sceneGroup = self.view &nbsp; &nbsp;-- Called prior to the removal of scene's view ("sceneGroup"). &nbsp; &nbsp;-- Insert code here to clean up the scene. &nbsp; &nbsp;-- Example: remove display objects, save state, etc. end --------------------------------------------------------------------------------- -- Listener setup scene:addEventListener( "create", scene ) scene:addEventListener( "show", scene ) scene:addEventListener( "hide", scene ) scene:addEventListener( "destroy", scene ) --------------------------------------------------------------------------------- return scene

squeegene · October 28, 2016, 7:07pm

Also worth noting: the console says

PANEL STATE IS: shown

whenever I click on the left button. However, the panel does not appear like it did before! Sorry for the late replies

rob · October 28, 2016, 7:48pm

There are a couple things going on.

First your module should return a table/object, something like this:

local widget = require("widget") local function panelTransDone( target ) --native.showAlert( "Panel", "Complete", { "Okay" } ) if ( target.completeState ) then print( "PANEL STATE IS: "..target.completeState ) end end local M = {} function M.createPanel() local panel = widget.newPanel { location = "left", onComplete = panelTransDone, width = display.contentWidth \* 0.5, height = display.contentHeight, speed = 250, inEasing = easing.outBack, outEasing = easing.outCubic } panel.background = display.newRect( 0, 0, panel.width, panel.height ) panel.background:setFillColor( 0, 0.25, 0.5 ) panel:insert( panel.background ) panel.title = display.newText( "Menu", 0, 0, native.systemFontBold, 18 ) panel.title:setFillColor( 1, 1, 1 ) panel:insert( panel.title ) return panel end return M

Then make sure to localize “panel” in your scene. Maybe put a:

local panel near the top of your scene. Right now you’re creating “panel” as a global and they are stomping on each other.

Rob

squeegene · October 28, 2016, 7:59pm

So I have createPanel returning M, as you have it , and inserted a

local panel

before any of the functions in menuScene.

However, both M and panel are nil. How do I call the createPanel() function in createPanel.lua?

squeegene · October 28, 2016, 9:45pm

Found the error

I ended up passing the table M as you did in the previous post. However, I tried

local panel = createPanel.createPanel()

before the function definitions and it still wasn’t working. What worked was leaving panel as global inside of the function so that I had

panel = createPanel.createPanel()

inside of the function scene:create.

OR, if I wanted to keep the panel as local, I could put that line inside of the button handler, like

local function handleLeftButton( event ) &nbsp; &nbsp; &nbsp; if ( event.phase == "ended" ) then &nbsp; &nbsp; &nbsp; &nbsp; local panel = createPanel.createPanel() &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;panel:show() &nbsp; &nbsp; &nbsp; end &nbsp; &nbsp; &nbsp; return true &nbsp; &nbsp;end

I guess defining the local panel outside of the function scene:create was the problem, though I’m not sure why that wouldn’t work.

rob · October 30, 2016, 3:47pm

Put

local createPanel = require("createPanel") local panel &nbsp;-- don't add anything extra here.

near the top of your scene. When you’re ready to create the panel:

panel = createPanel.createPanel()

Rob

squeegene · October 30, 2016, 4:01pm

Thank you so much for helping!

rob · October 28, 2016, 6:06pm