About ADDON_LOADED and VARIABLES_LOADED events

[Vlad]

The description of ADDON_LOADED:
Fires when an addon and its saved variables are loaded. Fires once for each addon (i.e. an addon loaded early in sequence will see ADDON_LOADED events for all addons loaded later).

The description of VARIABLES_LOADED:
Fires when non-addon-specific saved variables are loaded. Addons should generally use ADDON_LOADED to determine whether their saved variables have loaded.

Now here is an example of my own experience.
I use ADDON_LOADED to detect when my addon and the variables are loaded, for all my addons. Now the interesting part is that at some point in some addon I actually used the variables after ADDON_LOADED and they were not yet populated, so I played a bit and added VARIABLES_LOADED so after addon loaded I would also register VARIABLES_LOADED and after the variables one, THEN my variable was truly loaded.

It was weird, anyone else had such experience? :/

[Rilgamon]

Yes and no. I've not yet found the pattern for what is the right way to describe what happens sometimes during the loading process.
But I think its safe to say there is something not always the way we expect it

I get the best results when I check for the event that comes first addon_loaded or player_login. I know that normally player_login cant occur before addon_loaded still this construct helps me to not run in the problem you describe. PLAYER_ENTERING_WORLD is the event I found the most reliable point for data validity. But I feel bad when I use it instead of addon_loaded for initializing my addons

local name, addon = ...
local f = CreateFrame("Frame")
local login = true
 
local function onevent(self, event, arg1, ...)
    if(login and ((event == "ADDON_LOADED" and name == arg1) or (event == "PLAYER_LOGIN"))) then
        login = nil
        f:UnregisterEvent("ADDON_LOADED")
        f:UnregisterEvent("PLAYER_LOGIN")
        init()
    end
end
 
f:RegisterEvent("ADDON_LOADED")
f:RegisterEvent("PLAYER_LOGIN")
f:SetScript("OnEvent", onevent)

Edit:

btw variables loaded:

Until 3.0, VARIABLES_LOADED used to fire upon completion of the addon loading process; since 3.0, it is fired in response to CVars, Keybindings and other associated "Blizzard" variables being loaded, and may therefore be delayed until after PLAYER_ENTERING_WORLD. The event may still be useful to override positioning data stored in layout-cache.txt

http://www.wowpedia.org/AddOn_loading_process

[Xinhuan]

When ADDON_LOADED is fired, the addon it is fired for (in arg1) has loaded its own savedvariables.

Note that while loading your addon, if your addon causes a 2nd addon to be loaded using LoadAddOn() or otherwise, the 2nd addon would have its own ADDON_LOADED fire before yours and this can cause problems if your code didn't check arg1 == "myaddon".