Something

-- Core.lua
idActionBar = {}
idActionBar.bars = {}

function idActionBar:Enable()

    ... snip ...

    -- enable the bars
    for bar in self.bars do
        bar:Enable()
    end
end

function idActionBar:add(bar)
    if not self.bars[bar] then
        self.bars[bar] = bar
    end
end

idActionBar:Enable()

-- Pagedbar.lua
local Pagedbar = {}

function Pagedbar:Enable()
    self.wrap = CreateFrame('frame', nil, UIParent)

    idActionBar:newBar(self.wrap, 'idActionButton', 1, 1, 12, 0)

    self.wrap:ClearAllPoints()
    self.wrap:SetPoint('BOTTOM', UIParent, 'BOTTOM')

    MainMenuBar:Hide()
    self.wrap:Show()
end

idActionBar:add(Pagedbar)

-- Petbar.lua
local Petbar = {}

function Petbar:Enable()
    if not({Warlock=1, Hunter=1, Priest=1})[UnitClass('player')] then return end

    self.wrap = CreateFrame('frame', nil, UIParent)

    idActionBar:newBar(self.wrap, 'PetActionButton', 1, 1, 10, 0)

    self.wrap:ClearAllPoints()

    if self.showmain then
        self.wrap:SetPoint('BOTTOMLEFT', self.wrap, 'TOPLEFT', 0, 0)
    else
        self.wrap:SetPoint('BOTTOM', UIParent, 'BOTTOM')
    end

    self.wrap:Show()
end

idActionBar:add(Petbar)