class TrustyCms::Extension

def tab(name, options = {}, &block)
  @the_tab = admin.nav[name]
  unless @the_tab
    @the_tab = TrustyCms::AdminUI::NavTab.new(name)
    before = options.delete(:before)
    after = options.delete(:after)
    tab_name = before || after
    tab_object = admin.nav[tab_name]
    if tab_object
      index = admin.nav.index(tab_object)
      index += 1 unless before
      admin.nav.insert(index, @the_tab)
    else
      admin.nav << @the_tab
    end
  end
  if block_given?
    block.call(@the_tab)
  end
  @the_tab
end