[SDPhantom]

For now, you need to create a frame that'll run the code in its OnUpdate handler.

local lastupdate=0;--   Local storing how long since our last update
local frame=CreateFrame("Frame");-- Our frame
 
frame:SetScript("OnUpdate",function(self,elapsed)
    lastupdate=lastupdate+elapsed;--    Add elapsed to update local
    if lastupdate>1 then--  If it's been a second, update
        AgilityLine.text:SetText("Agility = ".. getRangedAgility());
        AttackPowerLine.text:SetText("AP = ".. getRangedAttackPower());
        CritLine.text:SetText("Crit = ".. getRangedCrit() .."%");
        MasteryLine.text:SetText("Mastery = ".. getRangedMastery());
        HasteLine.text:SetText("Haste = ".. getHaste() .."%");
 
        lastupdate=0;-- Reset to zero
    end
end);

In WoD, we'll be getting a new C_Timer system to handle this.
When this happens, your code would look like this.

C_Timer.NewTicker(1,function()--    Register a function to update every second
    AgilityLine.text:SetText("Agility = ".. getRangedAgility());
    AttackPowerLine.text:SetText("AP = ".. getRangedAttackPower());
    CritLine.text:SetText("Crit = ".. getRangedCrit() .."%");
    MasteryLine.text:SetText("Mastery = ".. getRangedMastery());
    HasteLine.text:SetText("Haste = ".. getHaste() .."%");
end);

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