digitalhelpersleague/asterism

class MediumUploader < CarrierWave::Uploader::Base

  storage :file
  before :cache, :save_original_filename

  def store_dir
    "uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
  end

  def save_original_filename(file)
    model.original_filename ||= file.original_filename if file.respond_to?(:original_filename)
  end

  def filename
    "#{secure_token}.#{file.extension}" if original_filename
  end

  protected

  def secure_token(length=32)
    var = :"@#{mounted_as}_secure_token"
    model.instance_variable_get(var) or model.instance_variable_set(var, SecureRandom.hex(length/2))
  end

  # Provide a default URL as a default if there hasn't been a file uploaded:
  # def default_url
  #   # For Rails 3.1+ asset pipeline compatibility:
  #   # ActionController::Base.helpers.asset_path("fallback/" + [version_name, "default.png"].compact.join('_'))
  #
  #   "/images/fallback/" + [version_name, "default.png"].compact.join('_')
  # end

  # Add a white list of extensions which are allowed to be uploaded.
  # For images you might use something like this:
  # def extension_white_list
  #   %w(wav mp3 ogg ulaw)
  # end

  # Override the filename of the uploaded files:
  # Avoid using model.id or version_name here, see uploader/store.rb for details.
  # def filename
  #   "something.jpg" if original_filename
  # end

end