app/uploaders/import_uploader.rb
# encoding: utf-8
class ImportUploader < CarrierWave::Uploader::Base
include ::CarrierWave::Backgrounder::Delay
include CarrierWave::MiniMagick
def store_dir
"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
end
def extension_white_list
%w(csv)
end
end