Flutter conditional rendering - good practice

main.dart

// Good
class MyWidget extends StatelessWidget {
  final List<int> numbers = [];  
  
  @override
  Widget build(BuildContext context) {
    return Container(
      child: Conditional.single(
        context: context,
        conditionBuilder: (BuildContext context) {
          // These lines live inside the condition builder only.
          final int firstEvenNumber = numbers.firstWhere(
            (element) => element % 2 == 0,
            orElse: () => null,
          );
          return firstEvenNumber != null;
        },
        widgetBuilder: (BuildContext context) {
          // the widget is created only when we need to render it,
          // while maintaining good readability.
          return Text(
            'Even number found.',
            style: TextStyle(
              color: Colors.green,
            ),
          );
        },
        fallbackBuilder: (BuildContext context) {
          return Text(
            'There is no even numbers.',
            style: TextStyle(
              color: Colors.red,
            ),
          );
        }
      ),
    );
  }
}