DistroPropaganda/code/rails31/e1/views/app/models/picture.rb

#---
# Excerpted from "Agile Web Development with Rails",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material,
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose.
# Visit http://www.pragmaticprogrammer.com/titles/rails4 for more book information.
#---
class Picture < ActiveRecord::Base

  validates_format_of :content_type, 
                      with: /^image/,
                      message: "--- you can only upload pictures"

  def uploaded_picture=(picture_field)
    self.name         = base_part_of(picture_field.original_filename)
    self.content_type = picture_field.content_type.chomp
    self.data         = picture_field.read
  end

  def base_part_of(file_name)
    File.basename(file_name).gsub(/[^\w._-]/, '')
  end
end