whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>(
  1. TResult? $default(
    1. int id,
    2. int expiry,
    3. List<Relay> relays,
    4. ConnectionMetadata proposer,
    5. Map<String, RequiredNamespace> requiredNamespaces,
    6. Map<String, RequiredNamespace> optionalNamespaces,
    7. String pairingTopic,
    8. Map<String, String>? sessionProperties,
    9. Map<String, Namespace>? generatedNamespaces,
    )?
)

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( int id,  int expiry,  List<Relay> relays,  ConnectionMetadata proposer,  Map<String, RequiredNamespace> requiredNamespaces,  Map<String, RequiredNamespace> optionalNamespaces,  String pairingTopic,  Map<String, String>? sessionProperties,  Map<String, Namespace>? generatedNamespaces)?  $default,) {final _that = this;
switch (_that) {
case _ProposalData() when $default != null:
return $default(_that.id,_that.expiry,_that.relays,_that.proposer,_that.requiredNamespaces,_that.optionalNamespaces,_that.pairingTopic,_that.sessionProperties,_that.generatedNamespaces);case _:
  return null;

}
}