class Middleman::Extensions::RelativeAssets

def after_configuration
  app.use ::Middleman::Middleware::InlineURLRewriter,
          id: :asset_hash,
          url_extensions: options.exts,
          source_extensions: options.sources,
          ignore: options.ignore,
          middleman_app: app,
          proc: method(:rewrite_url)
end

def initialize(app, options_hash={}, &block)
  super
  require 'middleman-core/middleware/inline_url_rewriter'
end

def rewrite_url(asset_path, dirpath, request_path)
  relative_path = Pathname.new(asset_path).relative?
  full_asset_path = if relative_path
    dirpath.join(asset_path).to_s
  else
    asset_path
  end
  return unless !full_asset_path.include?('//') && !asset_path.start_with?('data:')
  current_dir = Pathname(request_path).dirname
  Pathname(full_asset_path).relative_path_from(current_dir).to_s
end