Simple error

[Beaver]

Hi guys I have a problem. My program keeps throwing an error when I run it, it is probably a syntax error, but I dont know Lua well enough... here is the code:

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buttonTable = {}

function newButton (label, title, x, y, w, h)
   buttonTable[lable.title] = title
   buttonTable[lable.x] = x
   buttonTable[lable.y] = y
   buttonTable[lable.w] = w
   buttonTable[lable.h] = h
   return label
end

test1 = newButton (test1,buttonTest,2,2,6,4)
print (test1.title)


the error is:" .temp:5: attempt to index ? (a nil value)"

[QuickMuffin8782]

Here's a problem with your code. The incorrect buttonTable[>>lable<<.title] = title is causing a error, because you have a variable that you entered that is not specified.

I've fixed up your code so it won't error.
Here it is:

Code Select Expand

buttonTable = {}

function newButton (label, title, x, y, w, h)
   buttonTable[label.title] = title
   buttonTable[label.x] = x
   buttonTable[label.y] = y
   buttonTable[label.w] = w
   buttonTable[label.h] = h
   return label
end

test1 = newButton (test1,buttonTest,2,2,6,4)
print (test1.title)

[Beaver]

Actually I just checked, the original code is ok, the variable has the correct name, I just named it wrong here (my bad). But there is still that error.

[Lupus590]

Label is a string yes? What you probably want is something like this:

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-- I'm not copying all the code, just going to fix the broken function

local function newButton (label, title, x, y, w, h) -- seriously, look up scope and the local keyword like I said in another thread
-- it might be confusing at first but it is a good habit to get into
   buttonTable[label] = { label = lable, title = title, x = x, y = y, w = w, h = h }
   return buttonTable[label]
end

What this code does is create a new button 'object' and assign it to the buttonTable under the key 'label', it then returns the 'object'. As you might notice, we create a new table which we treat as the button object

[Beaver]

Ok thanks!

[QuickMuffin8782]

Code Select Expand

-- I'm not copying all the code, just going to fix the broken function

local function newButton (label, title, x, y, w, h) -- seriously, look up scope and the local keyword like I said in another thread
-- it might be confusing at first but it is a good habit to get into
  buttonTable[label] = { label = lable, title = title, x = x, y = y, w = w, h = h }
  return buttonTable[label]
end

What this code does is create a new button 'object' and assign it to the buttonTable under the key 'label', it then returns the 'object'. As you might notice, we create a new table which we treat as the button object

I would agree on this, this is way better on creating a new object. It's described in Jummit's Multitasking API which creates a object for a window. I've made a clipping on the code on how Jummit's API works on making a new window. I've managed to give credit for the iGP OS operating system, of course.

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programs.new = function(func, x, y, w, h, title)
  local x = x or 1
  local y = y or 1
  local w = w or widht
  local h = h or height
  local program = {
    x = x, y = y, w = w, h = h, title = title,
    term = window.create(
      defaultTerm, x, y, w, h
    ),
    selected = false,
    coroutine = coroutine.create(func),
    reposition = function(self, x, y)
      self.x, self.y = x, y
      self.term.reposition(x, y)
    end,
    resize = function(self, w, h)
      oldX, oldY = self.term.getPosition()
      self.term.reposition(oldX, oldY, w, h)
      os.queueEvent("term_resize")
    end,
    reset = function(self, x, y, w, h)
      self.x, self.y, self.w, self.h = x, y, w, h
      self.term.reposition(x, y, w, h)
      os.queueEvent("term_resize")
    end,
    terminateCount = 0
  }
  return program
end