how can i get addon to save a variable?

[Benholeo]

new to coding addons and have spent hours trying to figure out how to get variables to save. Now I feel like I have been swimming in snot and its time to actually ask for help. I am wondering whats wrong with the logic in this save, I think its myMod_Save and how it is used.

myMod.toc file
## Interface: 30300
## Title: myMod
## SavedVariablesPerCharacter: myMod_Save
## Dependencies:
myMod.lua
myMod.xml

myMod.lua file
myMod_Save = {
variable = 0
}

function myModFunction()
variable = variable + 1
end

myMod.xml file
<Ui xmlns="http://www.blizzard.com/wow/ui/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.blizzard.com/wow/ui/
..\..\FrameXML\UI.xsd">
<Frame name="myModFrame">
<Scripts>
<OnLoad>
myModFunction();
</OnLoad>
</Scripts>
</Frame>
</Ui>

[Torhal]

You're overwriting your SavedVariables every time your AddOn loads. You are also attempting arithmetic on an uninitialized global variable named "variable".

This is what you need to do:

local defaults = {
        variable = 0
}

myMod_Save = myMod_Save or defaults

function myModFunction() 
        myMod_Save.variable = myMod_Save.variable + 1
end

myMod_Save is declared in the global environment via your ToC file. The first time your AddOn is loaded, myMod_Save will be nil; you have to define it as a table (Generally, this is what you want. It could also simply be a string, number, etc). Every time after that, you want to use what you've already defined so what the code above does is say "Make the value of myMod_Save by the previous value, or make it defaults if this is the first time we've been run."


The table member "variable" needs to be accessed from that table - Lua isn't psychic, so it doesn't know unless you tell it.

I highly suggest that you read Programming in Lua so that you have some basic understanding of what you are dealing with.

[Benholeo]

Thank you

also I am not surprised that there were errors in other places since the mod was slapped together to illustrate how i was trying to save in my actual beta.

Edit: its now making a nil saved variable gonna have to keep working at it.
Thanks again, slowly im actually getting something done!

[Phanx]

Originally Posted by Torhal You're overwriting your SavedVariables every time your AddOn loads.

He's actually not, since saved variables aren't loaded yet when the main chunk executes.

Basically, all of your addon's files are read in the order they are listed in your TOC, and then your addon's saved variable(s) are read, and then the ADDON_LOADED event fires to say that your addon is done loading.

MySavedVar = {
    foo = bar,
    x = 2,
}

local MyAddonFrame = CreateFrame("Frame")
MyAddonFrame:RegisterEvent("ADDON_LOADED")
MyAddonFrame:SetScript("OnEvent", function(self, event, addon)
    if addon == "MyAddon" then
        print(MySavedVar.foo)
    end
end)

The first time this addon loaded, it would print "bar" to your chat frame. If you then typed:

/run MySavedVar.foo = "kittens!"

...then the next time the addon loaded, it would print "kittens!" instead.

[SDPhantom]

I don't think VARIABLES_LOADED fires before ADDON_LOADED. ADDON_LOADED fires when all of the addon's core lua and xml files have been read and parsed. It has nothing to do with saved variables. Only after ALL of the initial addons have been loaded, it then loads the variable files located in your account/character settings folder. After all those, it finally fires VARIABLES_LOADED.

The point of this statement, when dealing with previously saved variables, you'd want to hook the VARIABLES_LOADED event and never use ADDON_LOADED for that kind of thing. It's a completely unrelated event and you'll run into glitches using it.

As an added note, VARIABLES_LOADED fires multiple times; every time a CVar changes or a load-on-demand addon has its variables loaded. You should take steps to make sure it only runs on the first time your addon sees the event fire.

[Vrul]

Originally Posted by SDPhantom I don't think VARIABLES_LOADED fires before ADDON_LOADED. ADDON_LOADED fires when all of the addon's core lua and xml files have been read and parsed. It has nothing to do with saved variables. Only after ALL of the initial addons have been loaded, it then loads the variable files located in your account/character settings folder. After all those, it finally fires VARIABLES_LOADED. The point of this statement, when dealing with previously saved variables, you'd want to hook the VARIABLES_LOADED event and never use ADDON_LOADED for that kind of thing. It's a completely unrelated event and you'll run into glitches using it.

This is completely wrong.

What Phanx posted is correct.

[SDPhantom]

http://www.wowwiki.com/AddOn_loading_process
The VARIABLES_LOADED event was specifically made for this, but it looks like Blizzard screwed things up once again.

Writing an addon using the old behavior that isn't LoD should still work, the event still fires during initial load.
I haven't done any tests on variable availability since 3.0 when this change apparently happened.

[Phanx]

If you have these addons:

• Bartender
• GatherMate
• Mapster

Then the UI loading process looks like this:

1. Blizzard's FrameXML code loads
2. Bartender's TOC file is read
3. Bartender's XML and Lua files are read in the order they are listed in its TOC file
4. Bartender's SavedVariables file(s) are read
5. ADDON_LOADED fires with "Bartender" as arg1
6. GatherMate's TOC file is read
7. GatherMate's XML and Lua files are read in the order they are listed in its TOC file
8. GatherMate's SavedVariables file(s) are read
9. Mapster's TOC file is read
10. Mapster's XML and Lua files are read in the order they are listed in its TOC file
11. Mapster's SavedVariables file(s) are read
12. ADDON_LOADED fires with "GatherMate" as arg1
13. VARIABLES_LOADED may fire one or more times, with no arguments
14. PLAYER_LOGIN fires, with no arguments
15. PLAYER_ENTERING_WORLD fires, with no arguments
16. VARIABLES_LOADED may fire one or more times, with no arguments
17. PLAYER_ALIVE fires, with no arguments

Prior to WotLK, VARIABLES_LOADED fired once to signal that all non-LoD addons had been loaded. However, this is no longer the case, and addons wishing to know when all of their files and saved variables have been loaded should listen for the ADDON_LOADED event; addons wishing to know when all non-LoD addons and their saved variables have been loaded should listen for the PLAYER_LOGIN event. Addons wishing to know when an LoD addon and its saved variables have been loaded should listen for ADDON_LOADED. For all practical purposes, VARIABLES_LOADED is useless to addons.

[Benholeo]

The original problem was that saved variable where not being created in the WTF folder to begin with.

-The solution to that was not even declaring MyMod_Save in the lua.
-In otherwords Torhal's example worked

My second post stated that I wasn't acessing the data when I reloaded the addon.

-My solution was to use <OnUpdate> and check weither or not MyMod_Save was nil or a variable called default. if it was nil or default = true then MyMod_Save got set to default and if not MyMod_Save = MyMod_Save.
the default variable is so function can be reused elsewhere as a toDefault.

-Phanx had another solution where he listened specificly for Addon_Loaded event. And then I could have called my function. Which would lead to the same end result.

That's 2 solutions hope that helps someone after me.

[Phanx]

Originally Posted by Benholeo -My solution was to use <OnUpdate> and check weither or not MyMod_Save was nil or a variable called default. if it was nil or default = true then MyMod_Save got set to default and if not MyMod_Save = MyMod_Save. the default variable is so function can be reused elsewhere as a toDefault.

This is, to be blunt, a horrible solution. You should only use polling (eg. an OnUpdate script) when it's absolutely necessary. You should definitely never use it when there is an event that fires exactly when the information you want becomes available.

[Mischback]

Originally Posted by Phanx This is, to be blunt, a horrible solution.

You can't stress this point enough!

In programmer's words, 'OnUpdate' checking for things is 'expensive', which means that you're doing something on EVERY frame update (or in given interval, depending on how you implement it), but chances are high, that it is most of the time not necessary.

As Phanx said: If there's an event, which provide you the information you want, just use that!

[Seerah]

To illustrate how often your OnUpdate code would be run... As mentioned above, it runs for every frame update/draw/refresh.

If you have 60fps (frames per second), then your code would be run 60 times every second.

[Benholeo]

I come back and my invented solution gets owned, I figured it fired every time the addon has an update and not the game. Switching to addonloaded event. Please dont kill me.