[Akryn]

Originally Posted by opismahname Or could you post how the entire code would be?

I would be happy to if you'd like; although wouldn't that invalidate the point of trying to make your own addon?

Otherwise:

What you want to do is put some checks in your OnEvent function itself, the function that you call eventHandler.

frame:SetScript("OnEvent", eventHandler)

and

frame:RegisterEvent("UNIT_AURA");

are both already correct as they are. You need to put some logic in eventHandler to detect the three things I mentioned above:

local function eventHandler(self, event, ...)
--some stuff goes here
--your existing code
end