Sometimes I hate this :)

[skyraker]

So, I'm cleaning up my add-on by shifting more code (such as registering events) to their own functions, then calling them as necessary. I shifted the code that defines my top down window and the label control for my info bar into its own function. The label control is updated every tick.

Here's my crux. The add-on works still, but I'm getting a nil function error on the call to the label in the update function. Oddly, if I dismiss the error five times, it goes away until the next reload.

So, inside function: MS.toolText = WM:CreateControl("lsGoldT",statWin,CT_LABEL)

In update function: MS.toolText:SetText(MS.globals.barString)

This worked with no errors if I defined MS.toolText outside a function.

[Seerah]

Are you creating your IsGoldT control before the OnUpdate handler is set?

[skyraker]

Using OnUpdate in the xml. Should I move it out of there?

[Seerah]

I don't know. Is MS.toolText being created before the OnUpdate script is defined?

[skyraker]

Yes, the function that creates it is being called in my initialization function, which is called with EVENT_ADD_ON_LOADED. Is it possible that the update handler is being called before that?

EDIT: Just for clarification, this is the current order of things in my add-on:
Initial Declarations
Initialization Function - Calls functions to register events post-add-on start, setup the initial variable values, and create the bar
EVENT_ADD_ON_LOADED is registered - calls the above mentioned Init function
Function to create toolbar - creates top level window, then creates MS.toolText
Function for registering events post load - called from init function above
Function to setup initial variables - called from init function above
Helper function for counting saved variables
Update Handler Function
...

[Seerah]

So your OnUpdate handler is set in the main chunk of the addon? Not during or after the EVENT_ADD_ON_LOADED event?

[skyraker]

Originally Posted by Seerah So your OnUpdate handler is set in the main chunk of the addon? Not during or after the EVENT_ADD_ON_LOADED event?

Is the add-on loaded event supposed to be after everything now? But that would not explain why it worked before my changes. Maybe my changes were the problem?

What I did:

• Moved both the top-level window definition and the toolText definition from outside any function to inside a function.
• Changed top-level window and toolText to be members of the addon's global table MS.
• Added call to this new function from my initialization function.

The funny thing is that the add on still works after you clear the errors out. Typically something that give an error about getting nil when it expects something else indicates something is broken and the add on doesn't work.

[Seerah]

EVENT_ADD_ON_LOADED fires when your addon has finished loading and your previously saved variables are ready to be accessed. Assume this is your addon below - I'll comment the order in which everything occurs.

YourAddon.txt

## Title: YourAddon

YourAddon.lua     --1: this file and its contents gets loaded into memory first
YourAddon.xml     --6: now that the above is finished, this file gets executed

YourAddon.lua - this file is loaded into memory from top to bottom

local myVar, counterLabel     --2: these local variables exist in memory now but haven't been assigned anything yet (nil)
 
--3: this function is loaded into memory but hasn't actually been called/run yet
local function YourAddonInitialize()
     EVENT_MANAGER:RegisterForEvent("YourAddon", EVENT_PLAYER_DEAD, YourAddonEvent)     --12: this other event gets registered for
     counterLabel = WINDOW_MANAGER:CreateControl("YourAddonFrameCounter", YourAddonFrame, CT_LABEL)     --13: the label is now created (meanwhile, the OnUpdate script has tried to access it multiple times)
     myVar = 0     --14: the counter is set to its initial value
end
 
--4: the event is registered for, but hasn't fired yet, and so still hasn't called the function
EVENT_MANAGER:RegisterForEvent("YourAddon", EVENT_ADD_ON_LOADED, function(event, addon)
          if addon == "YourAddon" then     --11: your addon and its saved variables have finished loading, so EVENT_ADD_ON_LOADED fires and calls the initialize function since the addon argument matches the name of our addon now
               YourAddonInitialize()
          end
     end)
 
--5: this function is loaded into memory but hasn't been called yet
function YourAddonUpdate()     --9...: this begins to be called constantly starting with when the handler is set at #8 below
     YourAddonFrameCounter:SetText(myVar)     --note it's trying to access the counter which still hasn't been created yet
     myVar = myVar + 1
end

YourAddon.xml - this file is executed from top to bottom

<GuiXml>
    <Controls>
        <TopLevelControl name="YourAddonFrame">     --7: your toplevel window is created
            <Dimensions x="200" y="42" />
            <Anchor point="CENTER" />
 
            <OnUpdate>
                YourAddonUpdate()     --8: your OnUpdate handler is set to this function - this now begins firing and calls this function according to your frame rate (50 times per second, if at 50fps)
            </OnUpdate>
 
            <Controls>
                <Backdrop name="$(parent)BG" inherits="ZO_ThinBackdrop" />     --10: the bg frame is created
            </Controls>
        </TopLevelControl>
    </Controls>
</GuiXml>

Now... this isn't the exact format that you described your addon to be, but am I close? Do you see the error(s)?

[skyraker]

Yes, so it was when I removed the control definitions into a function. When they were globals they were defined before my OnUpdate handler.

[Seerah]

"globals" is the wrong term, but yes. It was a scoping issue.

[skyraker]

Aye, and thanks to you it is now completely fixed.

[Seerah]

Wonderful.