build method

@override LogSpan build()

Builds this span into another span, or returns itself if already terminal.

Override this for composable spans that build to other spans. Default implementation returns this.

Example:

class Timestamp extends LeafSpan {
  final DateTime date;
  Timestamp(this.date);

  @override
  LogSpan build() => PlainText('${date.hour}:${date.minute}');
}

Implementation

@override
LogSpan build() {
  final str = message?.toString() ?? '';
  if (str.isEmpty) return EmptySpan();
  return PlainText(str);
}