[go_router_builder] Allow the user to specify a type converter of the parameters #112152

enum MyEnum {
  myFirstEntry,
  mySecondEntry,
}

@TypedGoRoute<MyRoute>(path: '/my-path')
class MyRoute extends GoRouteData {
  const MyRoute({
    this.myBoolean = false,
    this.myEnum,
  });

  final bool myBoolean;

  final MyEnum? myEnum;

  @override
  Widget build(BuildContext context) => const MyScreen();
}

enum MyEnum {
  myFirstEntry,
  mySecondEntry,
}

@TypedGoRoute<MyRoute>(path: '/my-path')
class MyRoute extends GoRouteData {
  const MyRoute({
    this.myBoolean = false,
    this.myEnum,
  });
  
  @TypedGoRouteParameter<bool>(name: 'my-boolean')
  final bool myBoolean;
  
  @MyEnumConverter()
  final MyEnum? myEnum;

  @override
  Widget build(BuildContext context) => const MyScreen();
}


class MyEnumConverter extends TypedGoRouteParameter<MyEnum> {
  class MyEnumConverter(super.name);

  @override
  String? toUrlString(MyEnum myEnum) {
    // Return the correct format here.
    // If `null` is returned, fall back to the existing behavior.
  }

  @override
  MyEnum? fromUrlString(String value) {
    // Return the correct value here.
    // If `null` is returned, fall back to the existing behavior.
  }
}