whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? threadViewPost(
    1. ThreadViewPost data
    )?,
  2. TResult? notFoundPost(
    1. NotFoundPost data
    )?,
  3. TResult? blockedPost(
    1. BlockedPost 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( ThreadViewPost data)?  threadViewPost,TResult? Function( NotFoundPost data)?  notFoundPost,TResult? Function( BlockedPost data)?  blockedPost,TResult? Function( Map<String, dynamic> data)?  unknown,}) {final _that = this;
switch (_that) {
case UThreadViewPostParentThreadViewPost() when threadViewPost != null:
return threadViewPost(_that.data);case UThreadViewPostParentNotFoundPost() when notFoundPost != null:
return notFoundPost(_that.data);case UThreadViewPostParentBlockedPost() when blockedPost != null:
return blockedPost(_that.data);case UThreadViewPostParentUnknown() when unknown != null:
return unknown(_that.data);case _:
  return null;

}
}