Flutter数据存储插件di_storage的使用

DiStorage 是一个轻量级的依赖注入库，适用于 dart。其主要优势在于代码量小（大约200行左右）。因此，你可以查看代码并确保它的工作原理。你也可以确定程序中不包含任何后门等。

特性

• 注册（绑定）项目依赖并检索它们。
• 取消注册（解绑）项目依赖。
• 注册（绑定）依赖项的作用域。
• 取消注册（解绑）依赖项的作用域。
• 依赖项生命周期管理。

使用

要使用此插件，在你的 pubspec.yaml 文件中添加 di_storage 作为依赖。

示例

绑定、使用和移除依赖

DiStorage.shared.bind<SomeInterface>(
  module: null,
  () => SomeInterfaceImpl(),
  lifeTime: const LifeTime.single(),
);

DiStorage.shared.bind<SomeUsecase>(
  module: null,
  () => SomeUsecase(
    someInterface: di.resolve(),
  ),
  lifeTime: const LifeTime.prototype(),
);
// ...
final SomeInterface someInterface = DiStorage.shared.resolve();
final SomeUsecase someUsecase = DiStorage.shared.resolve();
// ...
// 当不再需要这些依赖时，可以选中移除它们
DiStorage.shared.remove<SomeInterface>();
DiStorage.shared.remove<SomeUsecase>();

绑定、使用和移除依赖项的作用域

class FirstDiScope extends DiScope {
  [@override](/user/override)
  void bind(DiStorage di) {
    di.bind<SomeInterface>(
      module: this,
      () => SomeInterfaceImpl(),
      lifeTime: const LifeTime.single(),
    );

    di.bind<SomeUsecase>(
      module: null,
      () => SomeUsecase(
        someInterface: di.resolve(),
      ),
      lifeTime: const LifeTime.prototype(),
    );
  }
}

class OtherDiScope extends DiScope {
  [@override](/user/override)
  void bind(DiStorage di) {
    di.bind<OtherInterface>(
      module: this,
      () => OtherInterfaceImpl(),
      lifeTime: const LifeTime.single(),
    );

    di.bind<OtherUsecase>(
      module: null,
      () => OtherUsecase(
        someInterface: di.resolve(),
      ),
      lifeTime: const LifeTime.prototype(),
    );
  }
}

/// 绑定
FirstDiScope().bind(DiStorage.shared);
OtherDiScope().bind(DiStorage.shared);

final SomeUsecase someUsecase = DiStorage.shared.resolve();
final OtherUsecase otherUsecase = DiStorage.shared.resolve();

// ...
// 使用 `someUsecase` 和 `otherUsecase`
// ...

// 移除 `OtherDiScope`
DiStorage.shared.removeScope<OtherDiScope>();

// ...
final isOtherUsecaseAvailable = DiStorage.shared.canResolve<OtherUsecase>();

// `isOtherUsecaseAvailable` = `false`

致谢

感谢 Sergei 激励我开发自己的库，以便完全控制其功能。

完整示例

以下是一个完整的示例代码，展示了如何使用 di_storage 插件。

import 'package:di_storage/di_storage.dart';
import 'package:example/domain/do_something_repository.dart';
import 'package:example/domain/model/token_info.dart';
import 'package:example/domain/usecases/do_something_usecase.dart';
import 'package:example/domain/usecases/session_info_provider_usecase.dart';
import 'package:example/domain/usecases/sign_out_usecase.dart';
import 'package:example/presentation/common_widgets/blocking_loading_indicator.dart';
import 'package:example/presentation/di/auth_di_scope.dart';
import 'package:example/presentation/di/unauth_di_scope.dart';
import 'package:example/presentation/home_screen/home_screen.dart';
import 'package:example/presentation/sign_in_screen/sign_in_screen.dart';
import 'package:flutter/material.dart';
import 'package:rxdart/rxdart.dart';

final navigatorKey = GlobalKey<NavigatorState>();

void main() {
  // [_installUnauthZoneDependencies] 安装应用程序未认证区域的依赖
  _installUnauthZoneDependencies();

  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  [@override](/user/override)
  Widget build(BuildContext context) {
    final SessionInfoProviderUsecase sessionInfo = DiStorage.shared.resolve();

    return MaterialApp(
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      themeMode: ThemeMode.light,
      debugShowCheckedModeBanner: false,
      showSemanticsDebugger: false,
      home: BlockingLoadingIndicator(
        child: StreamBuilder<TokenInfo>(
            stream: sessionInfo.sessionInfoStream.doOnData(
          (sessionInfo) {
            if (sessionInfo.isValid) {
              // [_installAuthZoneDependencies] 安装应用程序认证区域的依赖
              _installAuthZoneDependencies();
            } else {
              // [_dropAuthZoneDependencies] 删除未认证区域中未使用的依赖
              _dropAuthZoneDependencies();
            }
          },
        ), builder: (context, snapshot) {
          final isAuthorized = snapshot.data?.isValid == true;

          // 展示在未认证区域中没有未使用的依赖
          if (!isAuthorized) {
            assert(
              DiStorage.shared.tryResolve<DoSomethingRepository>() == null,
            );

            assert(
              DiStorage.shared.tryResolve<DoSomethingUsecase>() == null,
            );

            assert(
              DiStorage.shared.tryResolve<SignOutUsecase>() == null,
            );
          }

          return Navigator(
            key: navigatorKey,
            pages: [
              if (isAuthorized)
                MaterialPage(
                  child: HomeScreen(
                    doSomethingUsecase: DiStorage.shared.resolve(),
                    signOutUsecase: DiStorage.shared.resolve(),
                  ),
                )
              else
                MaterialPage(
                  child: SignInScreen(
                    signInUsecase: DiStorage.shared.resolve(),
                  ),
                ),
            ],
            onPopPage: (route, result) {
              if (!route.didPop(result)) {
                return false;
              }

              if (navigatorKey.currentState?.canPop() == true) {
                return true;
              }

              return false;
            },
          );
        }),
      ),
    );
  }

  Future<void> onRoute(BuildContext context, Object action) async {}
}

/// [_installUnauthZoneDependencies] 安装应用程序未认证区域的依赖
void _installUnauthZoneDependencies() {
  final di = DiStorage.shared;
  UnauthDiScope().bind(di);
}

/// [_installAuthZoneDependencies] 安装应用程序认证区域的依赖
void _installAuthZoneDependencies() {
  final di = DiStorage.shared;
  AuthDiScope().bind(di);
}

/// [_dropAuthZoneDependencies] 删除未认证区域中未使用的依赖
void _dropAuthZoneDependencies() {
  DiStorage.shared.removeScope<AuthDiScope>();
}