Flutter：如何使用 `injectable` 包实现非标准代码流？

Question

假设我需要这个：

class EndpointProvider {
  String getEndpoint(String trigger) {
    // skipped for clarity
  }
}

class MyHttpClient implements BaseHttpClient {
  MyHttpClient(this.baseUrl, [String accessToken = '']);  
}

class MyRemoteDataProvider extends BaseDataProvider {
  MyRemoteDataProvider(this.httpClient)

  final BaseHttpClient httpClient;
}

目前的代码流程是：

final endpointProvider = EndpointProvider();
final endpoint = endpointProvider.getEndpoint('trigger');
final accessToken = getTokenFromStorage() ?? '';
final httpClient = MyHttpClient(endpoint.url, accessToke );
final dataProvider = MyRemoteDataProvider(httpClient);
dataProvider.do();

是否可以使用injectable 来实现这一点？

Answer 1

你可以试试这个：

@lazySingleton
class EndpointProvider {
  String getEndpoint(String trigger) {
    return 'https://api.example.com/$trigger';
  }
}

@LazySingleton(as: BaseHttpClient)
class MyHttpClient implements BaseHttpClient {
  final String baseUrl;
  MyHttpClient(EndpointProvider endpointProvider, [@Named('accessToken') String accessToken]) : baseUrl = endpointProvider.getEndpoint('my_endpoint');
}

@lazySingleton
class MyRemoteDataProvider extends BaseDataProvider {
  MyRemoteDataProvider(this.httpClient)

  final BaseHttpClient httpClient;
}

在同一个可注入配置文件中，您可以放置​​：

@module
abstract class Module {
  @Named('accessToken')
  String get accessToken => '';
}