overriding DecoratedEnumerableProxy

gistfile1.rb

class InvoicesController < ApplicationController
  def index
    respond_with id InvoicesDecorator.new(invoices, InvoiceDecorator)
  end
end


class InvoicesDecorator < Draper::DecoratedEnumerableProxy
  def method_regardless_of_invoices_empty_or_not
    "yay"
  end
end


class InvoiceDecorator < ApplicationDecorator
  decorates :invoice
#normal stuffs
end

#index.html.haml

#invoices
  = invoices.method_regardless_of_invoices_empty_or_not
  - invoices.each do |invoice|
    = invoice.amount