whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? repoRef(
    1. RepoRef data
    )?,
  2. TResult? repoStrongRef(
    1. RepoStrongRef data
    )?,
  3. TResult? messageRef(
    1. MessageRef data
    )?,
  4. TResult? unknown(
    1. Map<String, dynamic> data
    )?,
})

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( RepoRef data)?  repoRef,TResult? Function( RepoStrongRef data)?  repoStrongRef,TResult? Function( MessageRef data)?  messageRef,TResult? Function( Map<String, dynamic> data)?  unknown,}) {final _that = this;
switch (_that) {
case UModEventViewSubjectRepoRef() when repoRef != null:
return repoRef(_that.data);case UModEventViewSubjectRepoStrongRef() when repoStrongRef != null:
return repoStrongRef(_that.data);case UModEventViewSubjectMessageRef() when messageRef != null:
return messageRef(_that.data);case UModEventViewSubjectUnknown() when unknown != null:
return unknown(_that.data);case _:
  return null;

}
}