when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<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 switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs TResult when<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():
return $default(_that.$type,_that.id,_that.rev,_that.sentAt,_that.data,_that.$unknown);case _:
  throw StateError('Unexpected subclass');

}
}