decode<T> method Null safety

Future<T> decode<T>()

Decodes this object's bytes as T.

This method will select the Codec for contentType from the CodecRegistry. The bytes of this object will be decoded according to that codec. If the codec produces a value that is not T, a bad request error Response is thrown.

T must be a primitive type (String, int, double, bool, or a List or Map containing only these types). An error is not thrown if T is not one of these types, but compiled Conduit applications may fail at runtime.

Performance considerations:

The decoded value is retained, and subsequent invocations of this method return the retained value to avoid performing the decoding process again.

Implementation

Future<T> decode<T>() async {
  if (hasBeenDecoded) {
    return _cast<T>(_decodedData);
  }

  final codec =
      CodecRegistry.defaultInstance.codecForContentType(contentType);
  final originalBytes = await _readBytes(bytes);

  if (retainOriginalBytes) {
    _bytes = originalBytes;
  }

  if (codec == null) {
    _decodedData = originalBytes;
    return _cast<T>(_decodedData);
  }

  try {
    _decodedData = codec.decoder.convert(originalBytes);
  } on Response {
    rethrow;
  } catch (_) {
    throw Response.badRequest(
        body: {"error": "request entity could not be decoded"});
  }

  return _cast<T>(_decodedData);
}