gistfile1.rb

# no ApplicationHelper...
def toolbar(module_name,id,options={})
    acesso_geral = current_usuario.send("may_gerenciar_#{module_name}?")
    acesso_edit = current_usuario.special_permissions.updatable(module_name).exists?
    acesso_read = current_usuario.special_permissions.readable(module_name).exists?
    acesso_delete = current_usuario.special_permissions.deletable(module_name).exists?
    concat("<span class='toolbar'>")
    if(acesso_geral || acesso_edit) && (options[:actions].include?(:edit))
      concat(link_toolbar(module_name,id,"edit","Editar"))
    end  
    if(acesso_geral || acesso_read) && (options[:actions].include?(:index))
      concat(link_toolbar(module_name,nil,"index","Voltar"))
    end  
    if(acesso_geral || acesso_read) && (options[:actions].include?(:new))
      concat(link_toolbar(module_name,nil,"new","Novo"))
    end  
    concat("</span>")
  end

private
    def link_toolbar(module_name,id,_action,link_name)
      classes_link = "ui-state-default dw-clickable ui-corner-br ui-corner-bl"
      classes_icon = "dw-icon ui-icon "
      case _action
      when "edit"
        classes_icon << "ui-icon-pencil"
      when "index"
        classes_icon << "ui-icon-home"
      when "new"
        classes_icon << "ui-icon-circle-plus"
      end
      hash_link = {:controller => module_name, :action => _action}
      hash_link[:id] = id if id
      content_tag(:a, :href => url_for(hash_link),:class => classes_link) do
        "<span class='#{classes_icon}'></span>#{link_name}"
      end
    end

#na view
%div.heading.ui-widget-header.ui-corner-tr.ui-corner-tl.dw-header
  = "Carros"
  = toolbar "carros", nil,:actions => [:new]