whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. String $type,
    2. int? ver,
    3. String src,
    4. String uri,
    5. String? cid,
    6. String val,
    7. bool? neg,
    8. DateTime cts,
    9. DateTime? exp,
    10. Map<String, dynamic>? sig,
    11. 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,  int? ver,  String src,  String uri,  String? cid,  String val,  bool? neg,  DateTime cts,  DateTime? exp,  Map<String, dynamic>? sig,  Map<String, dynamic>? $unknown)?  $default,) {final _that = this;
switch (_that) {
case _Label() when $default != null:
return $default(_that.$type,_that.ver,_that.src,_that.uri,_that.cid,_that.val,_that.neg,_that.cts,_that.exp,_that.sig,_that.$unknown);case _:
  return null;

}
}