Flutter用例生成插件usecase_generator的使用

Flutter用例生成插件usecase_generator的使用

插件介绍

usecase_generator 是一个用于从 repository 类生成 usecase 类的生成器包。它需要 usecase_annotation 包来注解类。

使用步骤

1. 添加依赖项：

   • 在 pubspec.yaml 文件中添加 usecase_annotation 和 usecase_generator 作为 dev_dependencies，同时添加 build_runner 作为 dev_dependencies。

   dependencies:
     flutter:
       sdk: flutter
     usecase_annotation: latest
     usecase_generator: latest
     build_runner: any
   
   dev_dependencies:
     flutter_test:
       sdk: flutter
     build_runner: any
   

2. 创建 auth_repo.dart 类文件，并使用 @UseCase 或 @UseCase() 注解你的 repo 类以生成每个函数的 `usease 类：

   @UseCase()
   abstract class AuthRepository {
     void m1();
     Future<String> m2(int param1);
   }
   
   class AuthRepositoryImpl implements AuthRepository {
     // Concrete implementation
   }
   

3. 运行构建命令：

   flutter packages pub run build_runner build --delete-conflicting-outputs
   

   这将生成 auth_repo.uc.dart 文件中的类，如 M1UseCase 调用 authRepository.m1()，M2UseCase 调用 authRepository.m2()。

4. 如果希望所有 usecase 文件位于同一目录下，请在 pubspec.yaml 文件旁边创建一个 build.yaml 文件，并在此文件中添加以下内容：

   targets:
     $default:
       builders:
         usecase_generator|usecase_gen:
           options:
             build_extensions:
               "^lib/domain/repositories/{{}}.dart": "lib/domain/usecases/{{}}.uc.dart",
   

5. 动机 此包遵循 Uncle Bob 的干净架构方法，为您的仓库类创建 usecase 类。

6. Riverpod DI 该包支持 Riverpod 靠注入。您需要在 pubspec.yaml 文件中添加 flutter_riverpod 包。

   targets:
     $default:
       builders:
         usecase_generator|usecase_gen:
           options:
             isInjectableDI: false
   

   若要关闭河浦 DI，请将 isInjectableDI 设置为 true。

7. Injectable DI 该包也可以与 injectable 包一起工作。首先将 isInjectableDI 设置为 true。 然后，在 build.yaml 文件中添加以下内容：

   targets:
     $default:
       builders:
         injectable_generator:injectable_builder:
           options:
             auto_register: true
             class_name_pattern: "UseCase$"
         usecase_generator|usecase_gen:
           options:
             isInjectableDI: true
   

示例代码

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

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

  // This widget is the root of your application.
  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        // This is the theme of your application.
        //
        // Try running your application with "flutter run". You'll see the
        // application has a blue toolbar. Then, without quitting the app, try
        // changing the primarySwatch below to Colors.green and then invoke
        // "hot reload" (press "r" in the console where you ran "flutter run",
        // or simply save your changes to "hot reload" in a Flutter IDE).
        // Notice that the counter didn't reset back to zero; the application
        // is not restarted.
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  // This widget is the home page of your application. It it has a State object
  // (defined below) that contains fields that affect how it looks.

  // This class is the configuration for the state. It it holds the values
  // (in this case the title) provided by the parent (in this case the App widget)
  // and used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  [@override](/user/override)
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. it takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}