gistfile1.rb

require 'fileutils'
require 'action_controller/test_process'

module UploadedDataHelper
  def uploaded_data_of(path, mime_type = :auto)
    mime_type = detect_mimetype_of(File.basename(path)) if mime_type == :auto
    use_temppath(path) do |temppath|
      return ActionController::TestUploadedFile.new(temppath, mime_type)
    end
  end

  def use_temppath(filepath)
    begin
      tmppath = File.expand_path(File.basename(filepath), Dir.tmpdir)
      FileUtils.cp filepath, tmppath
      result = yield(tmppath)
    rescue => e
      RAILS_DEFAULT_LOGGER.error("load error: #{filepath} on '#{e}'")
    ensure
      FileUtils.rm_rf tmppath if tmppath && File.exist?(tmppath)
    end
    result
  end

  def detect_mimetype_of(filename)
    case (ext = File.extname(filename))
    when ".gif"
      "image/gif"
    when ".jpg", ".jpeg"
      "image/jpg"
    when ".png"
      "image/png"
    when ".pdf"
      "application/pdf"
    when ".zip"
      "application/zip"
    else
      RAILS_DEFAULT_LOGGER.error("detect mimetype error:'#{ext}' is unknown mimetype.")
    end
  end
end