module Sinatra module AssetPack module Css def self.preproc(str, assets) str.gsub(/url\(["']?(.*?)["']?\)/) { |url| file, options = $1.split('?') local = assets.local_file_for file url = if local if options.to_s.include?('embed') to_data_uri(local) else BusterHelpers.add_cache_buster(file, local) end else url end "url(#{url})" } end def self.to_data_uri(file) require 'base64' data = File.read(file) ext = File.extname(file) mime = Sinatra::Base.mime_type(ext) b64 = Base64.encode64(data).gsub("\n", '') "data:#{mime};base64,#{b64}" end end end end