def content_type=(content_type)
      return unless content_type
      new_header_info = parse_content_type(content_type.to_s)
      prev_header_info = parsed_content_type_header
      charset = new_header_info.charset || prev_header_info.charset
      charset ||= self.class.default_charset unless prev_header_info.mime_type
      set_content_type new_header_info.mime_type, charset
    end
def content_type=(content_type)
      return unless content_type
      new_header_info = parse_content_type(content_type.to_s)
      prev_header_info = parsed_content_type_header
      charset = new_header_info.charset || prev_header_info.charset
      charset ||= self.class.default_charset unless prev_header_info.mime_type
      set_content_type new_header_info.mime_type, charset
    end
Sets the HTTP response's content MIME type. For example, in the controller
 you could write this:

  response.content_type = "text/plain"

 If a character set has been defined for this response (see charset=) then
 the character set information will also be included in the content type
 information.