Flutter conditional rendering - bad practice

main.dart

// Bad
class MyWidget extends StatelessWidget {
  final List<int> numbers = [];
  
  @override
  Widget build(BuildContext context) {
    // These lines only related to the condition,
    // but they are at the topmost scope of the `build` function.
    final int firstEvenNumber = numbers.firstWhere(
      (element) => element % 2 == 0,
      orElse: () => null,
    );
    
    // For illustration purpose I put simple widgets here.
    // But you can imagine how bad the readability will be,
    // when the widget is more complex.
    final Widget widgetToRender = firstEvenNumber != null
        ? Text(
            'Even number found.',
            style: TextStyle(
              color: Colors.green,
            ),
          )
        : Text(
            'There is no even numbers.',
            style: TextStyle(
              color: Colors.red,
            ),
          );
    return Container(
      child: widgetToRender,
    );
  }
}