gistfile1.rb

# MODEL

class Step < ActiveRecord::Base
  belongs_to :book
  belongs_to :charpter
  belongs_to :exercice
  attr_accessible :image, :body, :number, :book, :charpter, :exercice

  has_attached_file :image
end

# form  - ignora a parte do flash[:notice], é só pra notícias
=form_tag('/step/cadastre', :multipart => true) do
  = file_field :image, :image, :multiple => true
	%br
	= submit_tag 'Salvar'

- if flash[:notice]
	%strong
		Resumo:
	%br
	= flash[:notice].html_safe