UnitSetRole() -- Cataclysm Help.

[suicidalkatt]

So I'm attempting to add an addition to an addon of mine to automatically set your roles when you join a party.

So far what I've got seems to work however I can't seem to set 2 roles at once.

Current configuration:

local s = {
	[1] = {
		[1] = 0,
		[2] = 0,
		[3] = 0
	},
	[2] = {
		[1] = 0,
		[2] = 0,
		[3] = 0			
	}
}
local function GetTreeMaxPoints(number)
	local treePicked
	local active = GetActiveTalentGroup()
	for z=1, GetNumTalentTabs() do
		local _,_,_,_,pointsSpent = GetTalentTabInfo(z, false, false, number)
		s[number][z] = pointsSpent
	end
	local t = s[number]	
	if t[1] > t[2] and t[1] > t[3] then
		return 1
	elseif t[2] > t[1] and t[2] > t[3] then
		return 2
	elseif t[3] > t[1] and t[3] > t[2] then
		return 3
	else
		return 0
	end	
end

function osAR()
	if GetNumPartyMembers() >= 1 then
		for i=1, GetNumTalentGroups() do
			local tree = GetTreeMaxPoints(i)
			local role = GetTalentTreeRoles(tree)
			if role then
				UnitSetRole("player", role)
			end
		end
	end
end

local f = CreateFrame("frame")
f:SetScript("OnEvent", osAR)
f:RegisterEvent("PARTY_MEMBERS_CHANGED")

This does set the roles but if you have more than one role it spams and swaps the roles.

UnitSetRole() hasn't been defined yet, and the wow UI addon usage of it doesn't seem to give much insight.

Any ideas?