Call function method (example 2 Frame button) to avoid rewriting code causing attempt to index local 'button' (a boolean value)

Getting Started Newbie Questions
#1

Hi all

I simply want to make the “2 Frame Button” from https://docs.coronalabs.com/api/library/widget/newButton.html reusable in my code. The problem I face is that the x-position, y-position and name are predefined in the original code. If i have 3 buttons they will all get the same x & y-position and the same name. I tried to create a function  functionInputs to add parameters to the function but this did not work. Any help would be highly appreciated.

Thank you!

– This example works but position and name is from “newButton2Frame.lua”

local newButton2Frame = require(“newButton2Frame”) – Works

local button1 = newButton2Frame – Works

– To give parameters for x-Position (600), y-Position (400) and name of button (button 1) does not work

– With this working i could easily create other buttons to not rewrite the code

local button2 = newButton2Frame.functionInputs(600, 400, “button 1”) – Does not work

newButton2Frame.lua

local widget = require( “widget” )

–

–local M = {} --> Did not work

– Tried to add function to use parameters for x, y & name

local function functionInputs(xValue, yValue, buttonName)

    – Function to handle button events

    local function handleButtonEvent( event )

    

        if ( “ended” == event.phase ) then

            print( “Button was pressed and released” )

        end

    end

    

    – Image sheet options and declaration

    – For testing, you may copy/save the image under “2-Frame Construction” above

    local options = {

        width = 240,

        height = 120,

        numFrames = 2,

        sheetContentWidth = 480,

        sheetContentHeight = 120

    }

    

    local buttonSheet = graphics.newImageSheet( “widget-button-file.png”, options )

    

    – Create the widget

    local button1 = widget.newButton(

        {

            sheet = buttonSheet,

            defaultFrame = 1,

            overFrame = 2,

            label = “button”,

            onEvent = handleButtonEvent

        }

    )

    

    – Center the button

    button1.x = xValue – display.contentCenterX

    button1.y = yValue --display.contentCenterY

    

    – Change the button’s label text

    button1:setLabel( “blubb”) – buttonName ) --“2-Frame” )

end

–return M

original code - https://docs.coronalabs.com/api/library/widget/newButton.html

– 2-Frame

local widget = require( “widget” )

 

– Function to handle button events

local function handleButtonEvent( event )

 

    if ( “ended” == event.phase ) then

        print( “Button was pressed and released” )

    end

end

 

– Image sheet options and declaration

– For testing, you may copy/save the image under “2-Frame Construction” above

local options = {

    width = 240,

    height = 120,

    numFrames = 2,

    sheetContentWidth = 480,

    sheetContentHeight = 120

}

local buttonSheet = graphics.newImageSheet( “widget-button-file.png”, options )

 

– Create the widget

local button1 = widget.newButton(

    {

        sheet = buttonSheet,

        defaultFrame = 1,

        overFrame = 2,

        label = “button”,

        onEvent = handleButtonEvent

    }

)

 

– Center the button

button1.x = display.contentCenterX

button1.y = display.contentCenterY

 

– Change the button’s label text

button1:setLabel( “2-Frame” )

#2

Not tested as not on a machine with Corona installed, but you should get the idea.

newButton2Frame.lua

[lua]

local m = {}

local widget = require( “widget” )

local options = {

      width = 240,

      height = 120,

      numFrames = 2,

      sheetContentWidth = 480,

      sheetContentHeight = 120

  }

  

local buttonSheet = graphics.newImageSheet( “widget-button-file.png”, options )

m.new = function (xValue, yValue, label, id, listener)

  local button = widget.newButton(

      {

          sheet = buttonSheet,

          defaultFrame = 1,

          overFrame = 2,

          label = “button”,

          onEvent = listener

      }

  )

  

  – Center the button

  button.x = xValue

  button.y = yValue

  

  – Change the button’s label text

  button:setLabel(label) – buttonName ) --“2-Frame” )

  button.id = id

  

  return button

end

return m

[/lua]

Usage:

[lua]

local newButton2Frame = require(“newButton2Frame”)   – load module

local function handleButtonEvent( event )

    

        if ( “ended” == event.phase ) then

            print( event.target.id…" button was pressed and released" )

        end

  

        – PUT LISTENER IN SCENE SO BUTTON ACTIONS CAN INTERACT WITH IT

end

local button1 = newButton2Frame.new(400,600, “My First Button”, “Play”, handleButtonEvent)

local button2 = newButton2Frame.new(500,600, “My Second Button”, “Settings”, handleButtonEvent)

[/lua]

#3

hello Nick

THANK YOU SO MUCH!

It works now!

The only thing i changed to your input was leaving this code inside of newButton2Frame.lua

    – Function to handle button events

    local function handleButtonEvent( event )

    

        if ( “ended” == event.phase ) then

            print( “Button was pressed and released” )

        end

    end

And now i can call

local newButton2Frame = require(“newButton2Frame”)

local button1 = newButton2Frame.new(250, 350, “button 1”)

local button2 = newButton2Frame.new(250, 500, “button 2”)

This is exactly was i needed! :smiley:

Thanks again Nick!

#4

No problem. Only issue I can see with having the handler inside of newButton2Frame.lua is if you need to call code outside of that module. 

#5

Not tested as not on a machine with Corona installed, but you should get the idea.

newButton2Frame.lua

[lua]

local m = {}

local widget = require( “widget” )

local options = {

      width = 240,

      height = 120,

      numFrames = 2,

      sheetContentWidth = 480,

      sheetContentHeight = 120

  }

  

local buttonSheet = graphics.newImageSheet( “widget-button-file.png”, options )

m.new = function (xValue, yValue, label, id, listener)

  local button = widget.newButton(

      {

          sheet = buttonSheet,

          defaultFrame = 1,

          overFrame = 2,

          label = “button”,

          onEvent = listener

      }

  )

  

  – Center the button

  button.x = xValue

  button.y = yValue

  

  – Change the button’s label text

  button:setLabel(label) – buttonName ) --“2-Frame” )

  button.id = id

  

  return button

end

return m

[/lua]

Usage:

[lua]

local newButton2Frame = require(“newButton2Frame”)   – load module

local function handleButtonEvent( event )

    

        if ( “ended” == event.phase ) then

            print( event.target.id…" button was pressed and released" )

        end

  

        – PUT LISTENER IN SCENE SO BUTTON ACTIONS CAN INTERACT WITH IT

end

local button1 = newButton2Frame.new(400,600, “My First Button”, “Play”, handleButtonEvent)

local button2 = newButton2Frame.new(500,600, “My Second Button”, “Settings”, handleButtonEvent)

[/lua]

#6

hello Nick

THANK YOU SO MUCH!

It works now!

The only thing i changed to your input was leaving this code inside of newButton2Frame.lua

    – Function to handle button events

    local function handleButtonEvent( event )

    

        if ( “ended” == event.phase ) then

            print( “Button was pressed and released” )

        end

    end

And now i can call

local newButton2Frame = require(“newButton2Frame”)

local button1 = newButton2Frame.new(250, 350, “button 1”)

local button2 = newButton2Frame.new(250, 500, “button 2”)

This is exactly was i needed! :smiley:

Thanks again Nick!

#7

No problem. Only issue I can see with having the handler inside of newButton2Frame.lua is if you need to call code outside of that module.