[myrroddin]

function myaddon:OnEnable()
    self:RegisterEvent("SOME_EVENT")
 
    -- now call it if you need it right away
    self:SOME_EVENT()
end
 
function myaddon:OnDisable()
    self:UnregisterEvent("SOME_EVENT")
    -- or
    self:UnregisterAllEvents()
 
function myaddon:SOME_EVENT()
    -- handle it
end