def file=(file)
      self.data = file
      dis_set :content_type, file.content_type
      dis_set :filename, file.original_filename
    end
def file=(file)
      self.data = file
      dis_set :content_type, file.content_type
      dis_set :filename, file.original_filename
    end
Assigns new data from an uploaded file. In addition to the actions
 performed by <tt>data=</tt>, this will set <tt>content_type</tt> and
 <tt>filename</tt>.