[Help Required!] Class variable is always Nil Value

[DoktorHolmes]

Hello everyone!

I seem to be having an issue with another piece of code of mine.  I am trying to make a custom component that adds a UI text object and updates the text with the value of a variable called "count."  It all works just fine until I update the UI object itself where it won't recognize it at all, even as a variable built-in to the class.  It always just comes up as having a nil value.

The UI object I am trying to update is referred to as the "manabar" in the code, and the function that always returns the error is "mana:UpdateManaBar".

 

Here it is; would anyone mind error checking it for me?  

local mana = Class(function(self, inst, count, maximum, countstring, manabar)
    self.inst = inst
	count = 1
	countstring = tostring(count)
	maximum = 1000
	manabar = "null"
end)

function mana:reset()
	mana.count = 1
	mana.countstring = tostring(mana.count)
	mana.maximum = 1000
end
function mana:updateCountString()
	mana.countstring = tostring(mana.count)
	mana:UpdateManaBar(mana.manabar)
end

function mana:lowermana(inst, lowercount)
	mana.count = mana.count - lowercount
	if mana.count < 0 then
		mana.count = 0
	end
	mana:updateCountString()
end

function mana:addmana(inst, addcount)
	mana.count = mana.count + addcount
	if mana.count < 0 then
		mana.count = 0
	end
	mana:updateCountString()
end

function mana:AddManaBar(inst)
	local Text = require "widgets/text"
	local easing = require "easing"
	local Widget = require "widgets/widget"
	inst:DoTaskInTime( 0.5, function() 
	local controls = inst.HUD.controls
	mana.manabar = controls:AddChild(Text(NUMBERFONT, 28, "123"))
	mana.manabar:SetHAnchor(ANCHOR_MIDDLE)
	mana.manabar:SetVAnchor(0.4)
	mana.manabar:SetScale(1,.78,1)
	mana.manabar:Show()
	mana.manabar:SetString(mana.countstring)
end)
end
function mana:UpdateManaBar(manabar)
	manabar:SetString(mana.countstring)
end

return mana

Thank you so much!

-DoktorHolmes

Edited May 4, 2016 by DoktorHolmes

[Muche]

There seem to mixed up class and instance variables. Also constructor function mostly just sets values to local variables that get immediately forgotten.

Maybe try something like this?

local mana = Class(function(self, inst)
	self.inst = inst
	self.count = 1
	self.maximum = 1000
	self.manabar = nil
end)

function mana:reset()
	self.count = 1
	self.maximum = 1000
end

function mana:lowermana(lowercount)
	self.count = math.clamp(self.count - lowercount, 0, self.maximum)
	self:UpdateManaBar()
end

function mana:addmana(addcount)
	self.count = math.clamp(self.count + addcount, 0, self.maximum)
	self:UpdateManaBar()
end

function mana:AddManaBar()
	local Text = require "widgets/text"
	local easing = require "easing"
	local Widget = require "widgets/widget"
	self.inst:DoTaskInTime( 0.5, function() 
		local controls = self.inst.HUD.controls
		self.manabar = controls:AddChild(Text(NUMBERFONT, 28, tostring(self.count)))
		self.manabar:SetHAnchor(ANCHOR_MIDDLE)
		self.manabar:SetVAnchor(0.4)
		self.manabar:SetScale(1,.78,1)
		self.manabar:Show()
	end)
end

function mana:UpdateManaBar()
	self.manabar:SetString(tostring(self.count))
end

return mana

 

Edited May 4, 2016 by Muche

[DoktorHolmes]

Thanks,

I've tried to fix it up a bit (for example, the HUD.controls is suppposed to be assigned to the player) but it still doesn't seem to want to work.  It's still returning a nil value for some of the components.

local mana = Class(function(self, inst)
	self.inst = inst
	self.count = 1
	self.maximum = 1000
	self.manabar = nil
end)

function mana:reset()
	self.count = 1
	self.maximum = 1000
end

function mana:lowermana(lowercount)
	self.count = math.clamp(self.count - lowercount, self.maximum)
	self:UpdateManaBar()
end

function mana:addmana(addcount)
	self.count = math.clamp(self.count + addcount, self.maximum)
	self:UpdateManaBar()
end

function mana:AddManaBar(pl)
	local Text = require "widgets/text"
	local easing = require "easing"
	local Widget = require "widgets/widget"
	self.inst:DoTaskInTime( 0.5, function() 
		local controls = pl.HUD.controls
		self.manabar = controls:AddChild(Text(NUMBERFONT, 28, tostring(self.count)))
		self.manabar:SetHAnchor(ANCHOR_MIDDLE)
		self.manabar:SetVAnchor(0.4)
		self.manabar:SetScale(1,.78,1)
		self.manabar:Show()
	end)
end

function mana:UpdateManaBar()
	self.manabar:SetString(tostring(self.count))
end
mana:AddManaBar()
return mana

The error is the following:

scripts/components/mana.lua(27,1): attempt to index field 'inst' (a nil value)

It's occuring on the line "self.inst:DoTaskInTime( 0.5, function()"

Any ideas?

Edited May 4, 2016 by DoktorHolmes

[DoktorHolmes]

Okay, I've fixed that problem, but manabar is still being returned as a nil value.

 

(Line 38): attempt to index field 'manabar' (a nil value)

The script, once more:

local mana = Class(function(self, inst)
	self.inst = inst
	self.count = 1
	self.maximum = 1000
	self.manabar = nil
end)

function mana:reset()
	self.count = 1
	self.maximum = 1000
end

function mana:lowermana(lowercount)
	self.count = math.clamp(self.count - lowercount, self.maximum)
	self:UpdateManaBar()
end

function mana:addmana(addcount)
	self.count = math.clamp(self.count + addcount, self.maximum)
	self:UpdateManaBar()
end

function mana:AddManaBar(pl)
	local Text = require "widgets/text"
	local easing = require "easing"
	local Widget = require "widgets/widget"
	self.inst:DoTaskInTime( 0.5, function() 
		local controls = pl.HUD.controls
		self.manabar = controls:AddChild(Text(NUMBERFONT, 28, tostring(self.count)))
		self.manabar:SetHAnchor(ANCHOR_MIDDLE)
		self.manabar:SetVAnchor(0.4)
		self.manabar:SetScale(1,.78,1)
		self.manabar:Show()
	end)
end

function mana:UpdateManaBar()
	self.manabar:SetString(tostring(self.count))
end
return mana

This really is quite odd.  Any help you can give is appreciated!

Edited May 5, 2016 by DoktorHolmes
Adding code

[DoktorHolmes]

Never mind!  I have fixed it!  Thanks for your help!

Edited May 5, 2016 by DoktorHolmes

[Muche]

I'm glad you've got that fixed, I have a feeling it had to do with the way the mana instance was used in other parts.

Anyways, math.clamp function (defined in mathutil.lua expects 3 parameters, number, min and max). In the code above I can see only two. I am not sure, if it's caused by the forum's formatting (I had to specifically set no syntax highlighting, otherwise it would alter the pasted code), or if it is indeed as such on your side as well.