Spell power increase message and animation

[Benalish]

Hello,
I created this script for display a message whenever spell power get increased. I'd like to make the animation repeat only once. Are there better methods than the ones I'm using? What about spell power 'ping'?

local fs = UIParent:CreateFontString(nil, "OVERLAY", "GameTooltipText")
fs:SetPoint("CENTER")
fs:SetFont("Fonts\\FRIZQT__.TTF", 24, "OUTLINE")
fs:SetText("Spell power increased!")
fs:SetAlpha(0)
fs.flasher = fs:CreateAnimationGroup()
 
fs.flasher:SetLooping("NONE")
 
fs.flasher:SetScript(
    "OnUpdate", 
    function()
        if fs:GetAlpha() == 0 and fs.flasher:IsPlaying() then
            fs:Hide() 
        end
    end
)
 
local fade = fs.flasher:CreateAnimation("Alpha")
fade:SetDuration(5)
fade:SetChange(-1)
fade:SetOrder(1)
 
local spellDmg = GetSpellBonusDamage(6)
 
local onupdate = CreateFrame("Frame")
 
local spellDmg = GetSpellBonusDamage(6)
 
onupdate:SetScript("OnUpdate", function(self,elapsed)
    if GetSpellBonusDamage(6) > spellDmg then
        fs:SetAlpha(1)
        fs:Show()
        fs.flasher:Play()
    end
    spellDmg = GetSpellBonusDamage(6)
end)