Flutter实验性功能集成插件 experiment_sdk_flutter 的使用

特性

• fetch: 获取分配给用户的实验。可以使用以下属性：
  • variant: 获取每个实验的分配变体。
  • clear: 清除所有SDK缓存。
  • exposure: 跟踪分配变体的曝光（仅在使用 initializeWithAmplitude 或提供自定义 exposureTrackingProvider 时有效）。

开始使用

在开始使用此插件之前，您必须正确配置 Amplitude 帐户和项目以及 Amplitude Experiment。设置好实验后，您需要创建一个 deployment，并将生成的 API Key 用于 SDK 初始化。

初始化函数

initialize

该函数返回一个 ExperimentClient 实例，用于开始操作：

Experiment.initialize(
  apiKey: 'your-api-key',
  experimentConfig: ExperimentConfig(
    debug: true,
    instanceName: 'default-instance',
    fetchTimeoutMillis: 5000,
    retryFetchOnFailure: true,
    automaticExposureTracking: false,
  ),
);

initializeWithAmplitude

该函数返回与 initialize 相同的 ExperimentClient 实例配置，但会尝试将 Amplitude Analytic 作为曝光跟踪器：

Experiment.initializeWithAmplitude(
  apiKey: 'your-api-key',
  experimentConfig: ExperimentConfig(
    debug: true,
    instanceName: 'default-instance',
    fetchTimeoutMillis: 5000,
    retryFetchOnFailure: true,
    automaticExposureTracking: false,
  ),
);

Config 对象

ExperimentConfig 类允许您配置一些参数：

class ExperimentConfig {
  final bool? debug;
  final String? instanceName;
  final ExperimentVariant? fallbackVariant;
  final ExperimentVariantSource? source;
  final int? fetchTimeoutMillis;
  final bool? retryFetchOnFailure;
  final bool? automaticExposureTracking;
  final ExperimentExposureTrackingProvider? exposureTrackingProvider;

  ExperimentConfig({
    this.debug = false,
    this.instanceName = 'default-instance',
    this.fallbackVariant,
    this.source,
    this.fetchTimeoutMillis,
    this.retryFetchOnFailure,
    this.automaticExposureTracking = false,
    this.exposureTrackingProvider,
  });
}

使用示例

获取实验

获取用户分配的实验：

await Experiment.fetch(userId: 'testing', deviceId: 'device-id', userProperties: {'property': 'value'});

获取特定实验的变体

获取特定实验的分配变体：

final variant = Experiment.variant('flag-key');
print(variant);

获取所有实验和变体

获取用户分配的所有实验和变体：

final experiments = Experiment.all();
print(experiments);

清除缓存

清除所有缓存数据：

Experiment.clear();

跟踪曝光事件

跟踪变体的曝光事件（仅在使用 initializeWithAmplitude 或提供自定义 exposureTrackingProvider 时有效）：

Experiment.exposure('flag-key');

完整示例 Demo

以下是一个完整的示例代码，展示了如何在 Flutter 应用中集成 experiment_sdk_flutter 插件：

import 'package:experiment_sdk_flutter/experiment_sdk_flutter.dart';
import 'package:flutter/material.dart';

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

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

  [@override](/user/override)
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

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

  final String title;

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

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;
  final experiment = Experiment.initialize(
    apiKey: 'client-SyuVa4OF1vMBD5F59JMRwcZJutII4gZ2',
    experimentConfig: ExperimentConfig(
      debug: true,
      instanceName: 'default-instance',
      fetchTimeoutMillis: 5000,
      retryFetchOnFailure: true,
      automaticExposureTracking: false,
    ),
  );

  void _incrementCounter() async {
    await experiment.fetch(userId: 'testing');
    final experiments = experiment.all();

    print(experiments);
    setState(() {
      _counter++;
    });
  }

  [@override](/user/override)
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            const Text(
              'You have fetched the experiment this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headlineMedium,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: const Icon(Icons.add),
      ),
    );
  }
}