TFS 1.X+ [TFS 1.3] What could be wrong with this onHealthChange?

[Demnish]

Trying to add a boss monster which gets healed instead of damaged when it has a certain outfit:

function onHealthChange(creature, attacker, primaryDamage, primaryType, secondaryDamage, secondaryType, origin)
    if attacker then
        if creature:getOutfit() == 9 then
            primaryDamage = -primaryDamage
            secondaryDamage = -secondaryDamage
        end
    end
    return primaryDamage, primaryType, secondaryDamage, secondaryType
end

I've added the script to the creature, but it won't execute correctly, it does work however since if I make an error and attack the monster I get a console output
.
Something is wonky with creature:getOutfit() but I have no idea what.
9 is the lookType it should heal on.

 

[Alpha]

creature:getOutfit().lookType

 

[Demnish]

Thank you, it worked.
However I can't seem to use these:

primaryDamage = -primaryDamage
secondaryDamage = -secondaryDamage

Any ideas on an alternative? Because - doesn't work.

EDIT: Never mind, I solved it.
This works until a better method has been found:

function onHealthChange(creature, attacker, primaryDamage, primaryType, secondaryDamage, secondaryType, origin)
    if attacker then
        if creature:getOutfit().lookType == 9 then
            creature:getPosition():sendMagicEffect(CONST_ME_MAGIC_BLUE)
            creature:addHealth(-primaryDamage)
            creature:addHealth(-secondaryDamage)
            return true
        end
    end
    return primaryDamage, primaryType, secondaryDamage, secondaryType
end

 

[Infernum]

The damage will be negative either way, there's no need for you to manually send the damage yourself, all you have to do is use the return values.

 

[Demnish]

But having "-primaryDamage" for example won't make the damage positive aka heal.
So I'm quite at a loss on how to best implement this script.

 

[Infernum]

You need to use COMBAT_HEALING for the types instead of primary/secondaryType when changing the values to positive when you return.

 

[Demnish]

You're a legend mate, thank you.
Didn't know primary/secondaryType worked that way.
Do you know any good place I can read up on stuff like this?

Here is the script for those that wants it:

function onHealthChange(creature, attacker, primaryDamage, primaryType, secondaryDamage, secondaryType, origin)
    if attacker then
        if creature:getOutfit().lookType == 37 then
            primaryType = COMBAT_HEALING
            secondaryType = COMBAT_HEALING
        end
    end
    return primaryDamage, primaryType, secondaryDamage, secondaryType
end