whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? reportRef(
    1. ReportRef data
    )?,
  2. TResult? subjectRef(
    1. SubjectRef data
    )?,
  3. TResult? standingRef(
    1. StandingRef data
    )?,
  4. TResult? unknown(
    1. Map<String, dynamic> data
    )?,
})

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( ReportRef data)?  reportRef,TResult? Function( SubjectRef data)?  subjectRef,TResult? Function( StandingRef data)?  standingRef,TResult? Function( Map<String, dynamic> data)?  unknown,}) {final _that = this;
switch (_that) {
case UNotificationTargetReportRef() when reportRef != null:
return reportRef(_that.data);case UNotificationTargetSubjectRef() when subjectRef != null:
return subjectRef(_that.data);case UNotificationTargetStandingRef() when standingRef != null:
return standingRef(_that.data);case UNotificationTargetUnknown() when unknown != null:
return unknown(_that.data);case _:
  return null;

}
}