decodeXhttpExtra method

Map<String, dynamic>? decodeXhttpExtra(String? extra)

Decodes the XHTTP extra JSON object from URL query parameters.

Some subscriptions double-encode this field, so decoding is attempted a few times before parsing JSON. Invalid data is dropped instead of emitting malformed Xray config, which would hide the actual transport failure.

Implementation

Map<String, dynamic>? decodeXhttpExtra(String? extra) {
  if (extra == null || extra.isEmpty) {
    return null;
  }

  String candidate = extra;
  for (var i = 0; i < 3; i++) {
    try {
      final decoded = Uri.decodeComponent(candidate);
      if (decoded == candidate) {
        break;
      }
      candidate = decoded;
    } catch (_) {
      break;
    }
  }

  try {
    final decoded = jsonDecode(candidate);
    return decoded is Map<String, dynamic> ? decoded : null;
  } catch (_) {
    return null;
  }
}