when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>({
  1. required TResult done(),
  2. required TResult error(
    1. String error
    ),
  3. required TResult progress(),
})

A switch-like method, using callbacks.

As opposed to map, this offers destructuring. It is equivalent to doing:

switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}

Implementation

@optionalTypeArgs TResult when<TResult extends Object?>({required TResult Function()  done,required TResult Function( String error)  error,required TResult Function()  progress,}) {final _that = this;
switch (_that) {
case PickerLoadStatusDone():
return done();case PickerLoadStatusError():
return error(_that.error);case PickerLoadStatusProgress():
return progress();}
}