has form.lua file with code
local _M = {}
function _M.calc( a )
local quad = display.newRect(100,100,100,100)
end
return _M
and the file scene2.lua with the code
local form = require "form"
form.calc( )
I need the "quad / function" to be removed from the screen when it goes to another scene.
Add display object to scene group so composer remove it for you.
form.lua
local _M = {}
function _M.calc( group )
local quad = display.newRect( group, 100,100,100,100)
end
return _M
scene2.lua
local form = require "form"
form.calc( scene.view )
Related
I wanna call GameScene setSpecificSquare function in Square, it will occur 'attempt to index field 'squares' error.
In my understanding, require("GameScene") in onTouchEnded(touch event) do not get the last variable of GameScene, it has not been constructed, so it does not have squares attribute.
How to call GameScene static function setSpecificSquare in Square? Or in other word, how to get the last GameScene so I can set self.squares table?
Thanks in advanced!! :)
Square.lua
require "Cocos2d"
require "Cocos2dConstants"
local Square = class("Square",function()
return cc.Node:create()
end)
function Square.create()
local square = Square.new()
return square
end
function Square:ctor()
self.bg = cc.Sprite:create("square_bg.png")
self:addChild(self.bg)
self.isHighlight = true
local function onTouchEnded(touch,event)
--occur error here
require("GameScene"):setSpecificSquare()
end
end
return Square
GameScene.lua
require "Cocos2d"
require "Cocos2dConstants"
local GameScene = class("GameScene",function()
return cc.Scene:create()
end)
function GameScene.create()
local scene = GameScene.new()
return scene
end
function GameScene:ctor()
self.visibleSize = cc.Director:getInstance():getVisibleSize()
self.x = cc.Director:getInstance():getVisibleOrigin().x
self.y = cc.Director:getInstance():getVisibleOrigin().y
self.squares = {}
for i=0, 5 do
self.squares[i] = {} -- create a new row
for j=0, 5 do
self.squares[i][j] = nil
end
end
--add layer
self.bombLayer = cc.Layer:create()
self:addChild(self.bombLayer)
--add squares
self:addSquares()
end
function GameScene:addSquares()
for i=0,5 do
for j=0,5 do
local square = require("src/Square"):create()
square:setPosition(0+j*70,0+i*70)
self.bombLayer:addChild(square)
self.squares[i][j] = square
end
end
end
function GameScene:setSpecificSquare()
--can not access self.square here, occur attempt to index field 'squares' error
self.square[0][0].isHighLight
end
return GameScene
Move self.squares = {} out of ctor function, or call ctor function before calling addSquares, or you can just call this function inside addsquares.
The recommended method is moving it out of function and creating it on creation of your GameScene object:
require "Cocos2d"
require "Cocos2dConstants"
local GameScene = class("GameScene",function()
return cc.Scene:create()
end)
function GameScene.create()
local scene = GameScene.new()
return scene
end
GameScene.squares = {}
...
As stated in the title I would like to not only call an object from an external Lua file, but I would also like to group:insert() this object into my Menu page with the properties given to it in the external lua file. Is this possible and/or efficient? I would just really like to make sure data isn't repeated through out my project.
EDIT
Here's my code so far:
The group:insert() function is throwing me an error stating it was expecting a table and that I might have been trying to call a function in which case i should use ":" instead of "."
This is menu.lua:
local storyboard = require( "storyboard" )
local scene = storyboard.newScene()
local widget = require "widget"
local m = require ("myData")
local menuFunction = require("menuFunction")
local menuSwipe
-- =======================
-- menuSwipe()
-- =======================
menuSwipe = function(self, event)
local phase = event.phase
local touchID = event.id
if(phase == "began") then
elseif(phase == "moved") then
elseif(phase == "ended" or phase == "cancelled") then
if(m.menuActivator > 0) then
menuDown(m.invisiBar, event)
else
--m.layerInfo = layers
transition.to( menuFunction.menuBar, { x = menuFunction.menuBar.x, y = 0, time = 200 } )
--transition.to( layers, { x = menuFunction.menuBar.x, y = h, time = 100 } )
m.invisiBar = display.newRect( 0,0,w,25,6)
m.invisiBar.alpha = 0
m.menuActivator = 1
end
end
end
-- ++++++++++++++++++++++
-- menuDown()
-- ++++++++++++++++++++++
function menuDown(self, event)
local phase = event.phase
local touchID = event.id
if(phase == "began") then
elseif(phase == "moved") then
elseif(phase == "ended" or phase == "cancelled") then
if(m.menuActivator == 1) then
transition.to( menuFunction.menuBar, { x = m.menuInfo.x, y = h*.964, time = 200 } )
--transition.to( group, { x = 0, y = 0, time = 10 } )
m.menuActivator = 0
end
end
end
function scene:createScene( event )
local group = self.view
group:insert( menuFunction.menuBar ) -- *** ERROR occurs here
end
function scene:enterScene( event )
local group = self.view
end
function scene:exitScene( event )
local group = self.view
end
function scene:destroyScene( event )
local group = self.view
end
scene:addEventListener( "createScene", scene )
scene:addEventListener( "enterScene", scene )
scene:addEventListener( "exitScene", scene )
scene:addEventListener( "destroyScene", scene )
return scene
This is menuFunction.lua:
local m = require("myData")
local menu = require ("menu")
local w = display.contentWidth
local h = display.contentHeight
local menuFunction = {}
--menuBar
menuFunction.menuBar = display.newImage( "images/menuBar1.png")
menuFunction.menuBar.x = w*(1/2)
menuFunction.menuBar.y = h*1.465
menuFunction.menuBar.height = h
menuFunction.menuBar:setReferencePoint(display.TopLeftReferencePoint)
menuFunction.menuBar.touch = menu.menuSwipe
menuFunction.menuBar:addEventListener("touch", menuFunction.menuBar)
return menuFunction
This is the exact error message:
ERROR: table expected. If this is a function call, you might have used '.' instead of ':'
message**
Does this happen every time this code is called, or does it by any chance work the first time and then crashes? In your case, code could work the first time you enter the scene, but the second time you do, it may crash [if you remove scenes in between].
When you do a 'require' of a file, its contents are executed and returned value is saved in the global packages table. When you require the same file again, the returned value is taken from the global packages table instead, the code is not executed again.
So if you by any chance require this file in one spot of your app, and then call :removeSelf() and nil the reference of the menuBar, the display object will be removed and its reference will cease to exist, and calling the require again, will not recreate the object. Fully removing a scene will also remove the display objects.
So what you wanted to achieve is very sensible [contrary to what #Schollii says], but your "module" should allow creation of multiple objects if you want to get rid of them during runtime.
I'm not going to correct your code, just a simple example of how you can achieve this:
-- menu.lua
local menuCreator = {}
menuCreator.newMenu = function(params)
local menu = display.newGroup()
-- create your menu here
return menu
end
return menuCreator
Now anytime you do:
local menuCreator = require("menu.lua")
you will be able to call:
local menu = menuCreator.newMenu(someParams)
and get yourself a nice new menu wherever you need.
If it's not shown all the time on screen, it may be better to create a new one whenever you need it, and then remove it from the memory.
There are several issues with this, and none of them seem related to your error but fixing them will either also fix the error or make the cause of the error more obvious. Please fix following and update:
Although Lua allows it, don't use circular includes, where A includes B which includes A. Instead have menu require menuFunction and then call a creation function in menuFuntion:
-- menuFunction.lua
local m = require("myData")
-- require("menu") -- BAD! :)
local w = display.contentWidth
local h = display.contentHeight
local menuBar = display.newImage( "images/menuBar1.png")
menuBar.x = w*(1/2)
menuBar.y = h*1.465
menuBar.height = h
menuBar:setReferencePoint(display.TopLeftReferencePoint)
local menuFunction = { menuBar = menuBar }
function createMenuBar(menuSwipe)
menuFunction.menuBar.touch = menuSwipe
menuFunction.menuBar:addEventListener("touch", menuFunction.menuBar)
return menuFunction
end
-- menu.lua
function createScene(event)
local mf = require('menuFunction')
mfFunction = mf.createMenuBar(menuSwipe)
group:insert(menuFunction.menuBar)
end
Secondly out of the four calls to group:insert() the first 3 refer to objects that are not shown in the code and don't see relevant to problem, they should be removed or if you think relevant, comment why their code now shown, or show their code.
OK my first question was too vague so I'm going to start simple here. I am trying to get a random word from a table in another lua file (content.lua). I have gotten the code to run without errors but cannot get a word to display on the screen or via print in the command console. What am I missing?
game.lua
--lua for game
--Loading the local variables
--creates the storyboard variable and calls the storyboard api
local storyboard = require ("storyboard")
--calls the mydata.lua module
local myData = require( "mydata" )
--calls the sfx.lua where sounds are stored
local sfx = require( "sfx" )
--calls the operations.lua
local operations = require("operations")
local content = require("content")
local playOrder
local wordGraphic
local currQuestion = 1
local homeButton
--tells storyboard to create a new scene
local scene = storyboard.newScene()
function scene:createScene(event)
local gameScreen = self.view
--creates a transparent background image centered on the display
local gameBackground = display.newImage("images/graphics/jungle1.jpg")
gameBackground.x = display.contentWidth/2
gameBackground.y = display.contentHeight/2
gameScreen:insert(gameBackground)
homeButton = display.newImage("images/buttons/home.png")
homeButton.alpha = .8
homeButton.y = 70
gameScreen:insert(homeButton)
playOrder = operations.getRandomOrder(#content)
end
local function onHomeTouch(event)
if event.phase == "began" then
storyboard.gotoScene("start")
end
end
function scene:enterScene(event)
homeButton:addEventListener("touch", onHomeTouch)
audio.play(sfx.Bkgd)
--uses the operations.lua to get words in a random order from the content.lua
--shows a random word from the content.lua table
function showWord()
local word = content[playOrder[currQuestion]].word
print(word)
wordGraphic = self.view
wordGraphic:insert(word)
wordGraphic.x = display.contentWidth/2
wordGraphic.y = display.contentHeight/2
end
end
--next question function which clears the screen and loads a new random word
function scene:exitScene(event)
homeButton:removeEventListener("touch", onHomeTouch)
end
function scene:destroyScene(event)
end
--the actual event listeners that make the functions work
scene:addEventListener("createScene", scene)
scene:addEventListener("enterScene", scene)
scene:addEventListener("exitScene", scene)
scene:addEventListener("destroyScene", scene)
return scene
Here is the operations.lua that gets the random order function
--operations.lua
module(..., package.seeall)
--function to get a random piece of data
function getRandomOrder(amount)
local order ={}
local i
local temp
local temp1
for n = 1,amount do
order[n] = n
end
for i=0,9 do
for temp = 1,amount do
n = math.random(1, amount)
temp1 = order[temp]
order[temp] = order[n]
order[n] = temp1
end
end
return order
end
This is where the words I am attempting to display are stored. I did not include all of them.
--content.lua
return {
{
id = "after",
word = "after"
},
{
id = "again",
word = "again"
},
{
id = "an",
word = "an"
},
{
id = "any",
word = "any"
},
{
id = "ask",
word = "ask"
},
{
id = "as",
word = "as"
},
{
id = "by",
word = "by"
}
}
You're not calling showWord in any of the code that you've shown so far. This is probably why it isn't even printing to the console. The function is just contained within scene:enterScene and exits to the outer scope, defining itself as a global variable when enterScene is called.
How do I update or manipulate a sprite nested in several groups?
I first tried to add the "enterFrame" event directly to the desired class with the sprite (without success)
My code
local box = {}
-- PUBLIC FUNCTIONS
function box:new( )
local group = display.newGroup()
local image = display.newImage("crate.png")
group:insert(image)
function group:update()
image.rotation = image.rotation + 1
end
return group
end
return box
Second I though of adding a
Runtime:addEventListener("enterFrame", enterFrame)
in my scene, then looping through the groups added to the scene (scene.view) and call a custom update-function there that sends the update forward until it reaches my class. However I have not found a way of checking if the group has a update method or not. Now I just call update even if the group does not have it.
function enterFrame (event)
local group = scene.view
for i=1,group.numChildren do
group[i]:update()
end
end
local box = {}
You can try this simple solution
-- PUBLIC FUNCTIONS
function box:new( )
local group = display.newGroup()
local image = display.newImage("crate.png")
group:insert(image)
group.isThereUpdate = true
// or group.isThereUpdate = false
function group:update()
image.rotation = image.rotation + 1
end
return group
end
return box
function enterFrame (event)
local group = scene.view
for i=1,group.numChildren do
if group[i].isThereUpdate then
group[i]:update()
end
end
end
I have implemented OOP in my lua environment but it doesnt seem to be working.
I think it has something to do with how i am handling the __index and my improper use of require and module but I'm not 100% sure.
Here is the code:
Class = function( prototype )
local derived = {}
local derivedMT = {
--When indexing into a derived class, check the base class as well
__index = prototype,
--When invoking a class, return an instance
__call = function( proto, ... )
local instance = {}
local instanceMT = {
--When indexing into an instance, check the class hierarchy as well.
__index = derived,
--Calling instances is a no-no!
__call = function()
print( "WARNING! Attempt to invoke an instance of a class!" )
print( debug.traceback() )
return instance
end,
}
setmetatable( instance, instanceMT )
if ( instance.__constructor ) then
instance:__constructor( ... )
end
return instance
end,
}
setmetatable( derived, derivedMT )
return derived
end
And here is how I use it, the nil reference is a call to a base class function, that is the error/problem im having is it seems like the base class isn't being referenced.
require "Core.Camera.FreeCamera"
local T = Core.Camera.FreeCamera.FreeCamera(0,0,-35)
c = T:getObjectType() -- nil reference
print(c .." --Type" )
and here is Camera.lua the base class
local _G = _G
module(...)
local M = _G.Class()
Camera = M
function M:__constructor(x,y,z) --This never gets called.
--self.Active = false
--self.x = x
--self.y = y
--self.z = z
--self.ID = EngineManager:getCamera()
print("InCameraInstance_-_-_-_-_-__-_--_-__-_-_-_--_-_-_-_-_--_-_-_--_--__-_---_--_---__-")
end
function M:getObjectType()
return "camera"
end
And Finally Free Camera which attempts to inherit Camera.
local require = require
local _G = _G
module(...)
require "Core.Camera.Camera"
local M = _G.Class( _G.Core.Camera.Camera ) --Gross, lame might be the culprit
FreeCamera = M
function M:__constructor(x,y,z) ---WHOOPS, this does get called... the other one doesnt
self.Active = false
self.x = x
self.y = y
self.z = z
self.ID = _G.EngineManager:getCamera()
--_G.print("got Id of:" .. self.ID)
self:setCameraPosition(x, y, z, self.ID)
_G.print("<<<Camera in lua>>>")
end
I'm running out of ideas. any help would be appreciated.
Instead of:
local M = _G.Class( _G.Core.Camera.Camera )
you need to have:
local M = _G.Class( _G.Core.Camera.Camera.Camera )
First Camera is the directory name, second is the module name, third is the class name.
Edit: You can clean it up a bit like this:
local CameraModule = require "Core.Camera.Camera"
local M = _G.Class( CameraModule.Camera )