whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. String $type,
    2. String id,
    3. String rev,
    4. DateTime sentAt,
    5. @USystemMessageViewDataConverter() USystemMessageViewData data,
    6. Map<String, dynamic>? $unknown,
    )?
)

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 $type,  String id,  String rev,  DateTime sentAt, @USystemMessageViewDataConverter()  USystemMessageViewData data,  Map<String, dynamic>? $unknown)?  $default,) {final _that = this;
switch (_that) {
case _SystemMessageView() when $default != null:
return $default(_that.$type,_that.id,_that.rev,_that.sentAt,_that.data,_that.$unknown);case _:
  return null;

}
}