Override new function

dddent

Hello,

I'm trying to override the new function of a class that inherits the Sprite class, but I always get an error and I'm not sure why. Here is the code and the error:

Code:

Rectangle = Core.class(Sprite)   Rectangle.__new = Rectangle.new   Rectangle.new = function (x, y, width, height) self = Rectangle.__new() self:setX(x) self:setY(y)   self:beginPath() self:setLineStyle(2) self:setFillStyle(Shape.SOLID, 0xFF0000) self:moveTo(0,0) self:lineTo(x,0) self:lineTo(x,y) self:lineto(0,y) self:lineTo(0,0) self:endPath()   return self end   rect = Rectangle.new(50,50,100,100)   stage:addChild(rect)

Error:

button.lua is uploading. Uploading finished. [string "property.lua"]:59: stack overflow stack traceback: [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' ... [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' [string "property.lua"]:59: in function '__new' button.lua:8: in function 'new' button.lua:25: in main chunk

Thanks for help

cheers
David

ar2rsawseen

@dddent due to complections of postInit and some other Class system stuff, you can't override new function, but you can override __new function to achieve same effect:

Rectangle = Core.class(Sprite)   Rectangle._new = Rectangle.__new   Rectangle.__new = function (x, y, width, height) self = Rectangle._new() self:setX(x) self:setY(y)   self:beginPath() self:setLineStyle(2) self:setFillStyle(Shape.SOLID, 0xFF0000) self:moveTo(0,0) self:lineTo(x,0) self:lineTo(x,y) self:lineto(0,y) self:lineTo(0,0) self:endPath()   return self end   rect = Rectangle.new(50,50,100,100)   stage:addChild(rect)

ar2rsawseen

But in your case, you could have done simply:

Rectangle = Core.class(Sprite)   function Rectangle:init(x, y, width, height) self:setX(x) self:setY(y)   self:beginPath() self:setLineStyle(2) self:setFillStyle(Shape.SOLID, 0xFF0000) self:moveTo(0,0) self:lineTo(x,0) self:lineTo(x,y) self:lineto(0,y) self:lineTo(0,0) self:endPath() end   rect = Rectangle.new(50,50,100,100)   stage:addChild(rect)

dddent

@dddent due to complections of postInit and some other Class system stuff, you can't override new function, but you can override __new function to achieve same effect:

Rectangle = Core.class(Sprite)   Rectangle._new = Rectangle.__new   Rectangle.__new = function (x, y, width, height) self = Rectangle._new() self:setX(x) self:setY(y)   self:beginPath() self:setLineStyle(2) self:setFillStyle(Shape.SOLID, 0xFF0000) self:moveTo(0,0) self:lineTo(x,0) self:lineTo(x,y) self:lineto(0,y) self:lineTo(0,0) self:endPath()   return self end   rect = Rectangle.new(50,50,100,100)   stage:addChild(rect)

Hmm, I rewrote everything, and then overriding new as in my code worked fine, but I have no idea why it does work now and you saying, that it shouldn't work in the first place makes it even weirder...

I'll post the code, but due to some changes I made, its not working again, I'll post the error below, maybe s.o. can also help me with that:

Rectangle = Core.class(Shape)   Rectangle.b = Rectangle.new   function Rectangle.new(x,y,width,height, bwidth, bcolor, fcolor) self = Rectangle.b()   self:setX(x) self:setY(y)   self.width = width self.height = height   self.drawbg = function (_bwidth, _bcolor, _fcolor) print(type(_bwidth)) self:beginPath() self:setLineStyle(_bwidth or 1, _bcolor or 0x000000) self:setFillStyle(self.SOLID, _fcolor or 0x505050) self:moveTo(0,0) self:lineTo(self.width,0) self:lineTo(self.width, self.height) self:lineTo(0,self.height) self:lineTo(0,0) self:endPath() end   self.reset = function () self:beginPath() self:setLineStyle(bwidth or 1, bcolor or 0x000000) self:setFillStyle(self.SOLID, fcolor or 0x505050) self:moveTo(0,0) self:lineTo(self.width,0) self:lineTo(self.width, self.height) self:lineTo(0,self.height) self:lineTo(0,0) self:endPath() end   self:drawbg()   return self end

Error:

button.lua is uploading. Uploading finished. table button.lua:17: bad argument #1 to 'setLineStyle' (number expected, got table) stack traceback: button.lua:17: in function 'drawbg' button.lua:39: in function 'new' button.lua:50: in function 'new' menu.lua:1: in main chunk

EDIT: I intentionally didn't pass any arguments to drawbg() to underline, that the error even occurs when nil is passed as an argument for _bwidth, it always is a table...

ar2rsawseen

@dddent sorry for confusion, I meant that there was an internal __new function, that you have overriden, thus it did not work

about your last error then problem is that you define function with . and use it with :

So

self:drawbg() translates to self.drawbg(self) thus first parameter is always a table

All in all, this should work:

Rectangle = Core.class(Sprite)   function Rectangle:init(x, y, width, height) self:setX(x) self:setY(y)   self:beginPath() self:setLineStyle(2) self:setFillStyle(Shape.SOLID, 0xFF0000) self:moveTo(0,0) self:lineTo(x,0) self:lineTo(x,y) self:lineto(0,y) self:lineTo(0,0) self:endPath() end   function Rectangle:drawbg(_bwidth, _bcolor, _fcolor) print(type(_bwidth)) self:beginPath() self:setLineStyle(_bwidth or 1, _bcolor or 0x000000) self:setFillStyle(self.SOLID, _fcolor or 0x505050) self:moveTo(0,0) self:lineTo(self.width,0) self:lineTo(self.width, self.height) self:lineTo(0,self.height) self:lineTo(0,0) self:endPath() end   function Rectangle:rest () self:beginPath() self:setLineStyle(bwidth or 1, bcolor or 0x000000) self:setFillStyle(self.SOLID, fcolor or 0x505050) self:moveTo(0,0) self:lineTo(self.width,0) self:lineTo(self.width, self.height) self:lineTo(0,self.height) self:lineTo(0,0) self:endPath() end   rect = Rectangle.new(50,50,100,100) rect:drawbg()   stage:addChild(rect)

dddent

Thanks! @ar2rsawseen