when<TResult extends Object?> method

  1. @optionalTypeArgs
TResult when<TResult extends Object?>({
  1. required TResult applePay(
    1. List<ApplePayCartSummaryItem> summaryItems,
    2. List<ApplePayShippingMethod> shippingMethods,
    3. List<ApplePaySheetError>? errors
    ),
})

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( List<ApplePayCartSummaryItem> summaryItems,  List<ApplePayShippingMethod> shippingMethods,  List<ApplePaySheetError>? errors)  applePay,}) {final _that = this;
switch (_that) {
case _PlatformPaySheetUpdateParams():
return applePay(_that.summaryItems,_that.shippingMethods,_that.errors);case _:
  throw StateError('Unexpected subclass');

}
}