whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? unknown()?,
  2. TResult? video(
    1. List<File> files
    )?,
  3. TResult? image(
    1. List<File> files
    )?,
  4. TResult? vr(
    1. List<File> files
    )?,
  5. TResult? audio(
    1. List<File> files
    )?,
  6. TResult? html(
    1. List<File> files
    )?,
})

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()?  unknown,TResult? Function( List<File> files)?  video,TResult? Function( List<File> files)?  image,TResult? Function( List<File> files)?  vr,TResult? Function( List<File> files)?  audio,TResult? Function( List<File> files)?  html,}) {final _that = this;
switch (_that) {
case Unknown() when unknown != null:
return unknown();case Video() when video != null:
return video(_that.files);case Image() when image != null:
return image(_that.files);case Model3D() when vr != null:
return vr(_that.files);case Audio() when audio != null:
return audio(_that.files);case Html() when html != null:
return html(_that.files);case _:
  return null;

}
}