whenOrNull<TResult extends Object?> method

  1. @optionalTypeArgs
TResult? whenOrNull<TResult extends Object?>({
  1. TResult? android()?,
  2. TResult? ios()?,
  3. TResult? macos()?,
  4. TResult? web()?,
  5. TResult? linux()?,
  6. TResult? windows()?,
  7. TResult? fuchsia()?,
})

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()?  android,TResult? Function()?  ios,TResult? Function()?  macos,TResult? Function()?  web,TResult? Function()?  linux,TResult? Function()?  windows,TResult? Function()?  fuchsia,}) {final _that = this;
switch (_that) {
case AndroidPlatform() when android != null:
return android();case IosPlatform() when ios != null:
return ios();case MacosPlatform() when macos != null:
return macos();case WebPlatform() when web != null:
return web();case LinuxPlatform() when linux != null:
return linux();case WindowsPlatform() when windows != null:
return windows();case FuchsiaPlatform() when fuchsia != null:
return fuchsia();case _:
  return null;

}
}