whenOrNull<TResult extends Object?> method

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

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