when method

Widget when({ required Widget onSuccess(T value), required Widget onFailure(Failure failure), })

Transforms the Result state directly into a Flutter widget.

This method uses Dart 3 pattern matching to safely destructure the state, executing onSuccess with the unwrapped value if the operation succeeded, or onFailure with the failure details if it failed.

Example:

result.when(
  onSuccess: (data) => Text('Success: $data'),
  onFailure: (error) => Text('Error: ${error.message}'),
);

Implementation

Widget when({
  required Widget Function(T value) onSuccess,
  required Widget Function(Failure failure) onFailure,
}) {
  return switch (this) {
    // Destructures SuccessResult to extract the nested value inside the Success wrapper
    SuccessResult<T>(success: Success(:final value)) => onSuccess(value),

    // Destructures FailureResult to extract the underlying Failure object
    FailureResult<T>(failure: final fail) => onFailure(fail),
  };
}