ifModifiedSince property

DateTime? ifModifiedSince

If this is non-null and the requested resource hasn't been modified since this date and time, the server should return a 304 Not Modified response.

This is parsed from the If-Modified-Since header in headers. If headers doesn't have an If-Modified-Since header, this will be null.

Throws FormatException, if incoming HTTP request has an invalid If-Modified-Since header.


DateTime? get ifModifiedSince {
  if (_ifModifiedSinceCache != null) return _ifModifiedSinceCache;
  if (!headers.containsKey('if-modified-since')) return null;
  _ifModifiedSinceCache = parseHttpDate(headers['if-modified-since']!);
  return _ifModifiedSinceCache;