Lua get Buff duration

[Lybrial]

Hi,

i want to return how much time left on my buff.

i startet with:

function()
    local value = select(15, UnitBuff("player", "Blood Shield")) or 0
    
end

But now i dont know how to go on.
Can somebody give a hint?

[Rilgamon]

local name, rank, icon, count, debuffType, duration, expirationTime, unitCaster, isStealable, 
shouldConsolidate, spellId, canApplyAura, isBossDebuff, value1, value2, value3 = UnitBuff("unit", index or "name"[, "rank"[, "filter"]])

You check on the 15th argument. The time left is the expirationTime value.

Take a look at the 2nd example
http://wowpedia.org/API_UnitBuff

[Lybrial]

Ok but i still get lua errors and a strange behaviour of my bar:

function()
    local value = select(8, UnitBuff("player", "Blutschild")) or 0
    return value;
end

So with this i get the expirationTime and i return it. My goal is
to have a bar which shows when the buff will expire.
With the above code i just get lua errors.

11x Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1864: attempt to compare number with string

44x Interface\AddOns\WeakAuras\RegionTypes\aurabar.lua:649: attempt to perform arithmetic on field 'expirationTime' (a nil value) Interface\AddOns\WeakAuras\RegionTypes\aurabar.lua:649: in function <Interface\AddOns\WeakAuras\RegionTypes\aurabar.lua:647> Interface\AddOns\WeakAuras\RegionTypes\aurabar.lua:1053: in functio

[Phanx]

Re-read the documentation. The 8th return value is a string identifying the unit that cast the buff; the expiration time is arg7. Also, there's really no reason to use select here; it's just slowing things down for no reason.

function()
     local _, _, _, _, _, duration, expirationTime = UnitBuff("player", "Blutschild")
     return expirationTime
end

Or, if your function needs to return the amount of time left (instead of the time at which it ends) do this:

function()
     local _, _, _, _, _, duration, expirationTime = UnitBuff("player", "Blutschild")
     return expirationTime - GetTime()
end

[Lybrial]

Originally Posted by Phanx function() local _, _, _, _, _, duration, expirationTime = UnitBuff("player", "Blutschild") return expirationTime end

4x Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1864: attempt to compare number with nil Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1864: in function `SetEventDynamics' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1835: in function `ActivateEvent' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1816: in function `ScanEvents' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1730: in function `ForceEvents' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:2144: in function `ScanForLoads'

Originally Posted by Phanx function() local _, _, _, _, _, duration, expirationTime = UnitBuff("player", "Blutschild") return expirationTime - GetTime() end

9x [string "return function()..."]:3: attempt to perform arithmetic on local 'expirationTime' (a nil value) [string "return function()..."]:3: in function `durationFunc' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1860: in function `SetEventDynamics' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1835: in function `ActivateEvent' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1816: in function `ScanEvents' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:1730: in function `ForceEvents' Interface\AddOns\WeakAuras\WeakAuras-2.0.7.lua:2144: in function `ScanForLoads'

Maybe i should describe my problem a little bit better.

Im working with WeakAuras 2 And i have a bar to observe my Blood Shield of my DK.

This is the function i use to show how much damage my shield can block:

function () 
    local shield_value = select(15, UnitBuff("player", "Blutschild")) or 0;
    shield_value = math.floor(shield_value/1000);
    
    local max_health = UnitHealthMax("player");
    max_health = math.floor(max_health/1000);
    
    return string.format("%uk/%uk", shield_value, max_health);
end

My Trigger Code:

function()
    return true
end

My Reverse Trigger Code:

function()
    local a = UnitBuff("player", "Blutschild")
    return a == nil
end

And now i need Code for the duration so that my bar
shows how much time is left until my shield expires.
If i use one of your codes posted above i get the
posted lua errors and the bar starts randomly in the
middle of the bar and decreases.

[Phanx]

You're (probably) getting those errors because you don't currently have the buff active. I guess WeakAuras can't handle nil values itself (I don't actually use it) so just return a zero if UnitAura didn't return anything:

function()
     local _, _, _, _, _, duration, expirationTime = UnitBuff("player", "Blutschild")
     return expirationTime or 0
end

or:

function()
     local _, _, _, _, _, duration, expirationTime = UnitBuff("player", "Blutschild")
     return expirationTime and (expirationTime - GetTime()) or 0
end

Again, as I don't actually use WeakAuras, I don't know whether it needs the remaining time or the expiration time, but either of the above should make sure it doesn't receive any scary nil values.