app/models/asset.rb
class Asset < ActiveRecord::Base
# SCOPES
scope :cover, -> { where(cover: true) }
# ASSOCIATIONS
belongs_to :assetable, polymorphic: true
# MACROS
mount_uploader :asset, AssetUploader
include Rails.application.routes.url_helpers
# INSTANCE METHODS
def alt_name
asset.file.filename.split('.').first.gsub(/[_,-]/, ' ')
end
end