2016-11-25-setting-document-title-in-angular2-dart-improved-title-set-service-improved.dart

typedef String TitleNamingFunction(ComponentInstruction c);

@Injectable()
class TitleSetService {
  TitleNamingFunction nameStrategy;

  Router _router;
  Title _title;

  TitleSetService(this._router, this._title) {
    nameStrategy = _defaultNameStrategy;
   _router.subscribe(_setTitleFromRoute);
  }

  Future<Null> _setTitleFromRoute(String url) async {
    //identify component instruction from routed url
    ComponentInstruction compInst = (await _router.recognize(url))?.component;
    if (compInst != null) {
      _title.setTitle(nameStrategy(compInst));
    }
  }

  String _defaultNameStrategy(ComponentInstruction compInst) {
    return compInst.routeName;
  }
}