gistfile1.rb

  def cache document
    FileUtils.mkdir_p File.join(RAILS_ROOT, 'private')
    basename = File.basename(document.filename)
    pathname = File.join(RAILS_ROOT, 'private', document.id.to_s, basename)

    cached =
      begin
        File.stat(pathname).mtime <= document.created_at
      rescue
        false
      end

    unless cached
      dirname, basename = File.split pathname
      FileUtils.mkdir_p dirname
      open(pathname, 'w') do |f|
        f.write document.current_data
        log "cached #{ pathname }"
      end
    end

    pathname
  end

  def inline!
    disposition = params[:disposition] || 'attachment';

    if RAILS_ENV == 'production'
      begin
        x_send_file cache(@document), :disposition => disposition
      rescue Object => e
        send_data(@document.current_data, {
          :filename    => @document.filename,
          :type        => @document.content_type,
          :disposition => disposition,
        })
      end
    else
      send_data(@document.current_data, {
        :filename    => @document.filename,
        :type        => @document.content_type,
        :disposition => disposition,
      })
    end
  end