whenOrNull<TResult extends Object?> method

@optionalTypeArgs TResult? whenOrNull<TResult extends Object?>(TResult? $default(String? returnUrl, String? cancelUrl, String? brandName, String? locale, String? landingPage, PPShippingPreference? shippingPreference, PPUserAction? userAction,)?)

A variant of when that fallback to returning null

It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case _:
    return null;
}

Implementation

@optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  TResult? Function(
          String? returnUrl,
          String? cancelUrl,
          String? brandName,
          String? locale,
          String? landingPage,
          PPShippingPreference? shippingPreference,
          PPUserAction? userAction)?
      $default,
) {
  final _that = this;
  switch (_that) {
    case _PPOrderAppContext() when $default != null:
      return $default(
          _that.returnUrl,
          _that.cancelUrl,
          _that.brandName,
          _that.locale,
          _that.landingPage,
          _that.shippingPreference,
          _that.userAction);
    case _:
      return null;
  }
}