when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>(
  1. TResult $default(
    1. Set<String> keys
    ), {
  2. required TResult sendKeyValue(
    1. Object value
    ),
})

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(@JsonKey(name: 'keys') Set<String> keys) $default, {
  required TResult Function(Object value) sendKeyValue,
}) {
  final _that = this;
  switch (_that) {
    case SpViewDefault():
      return $default(_that.keys);
    case SpSendKeyValueModel():
      return sendKeyValue(_that.value);
  }
}