Flutter多渠道打包的解决方案（walle）

背景

我们的应用集成了TalkingData这个第三方工具来统计日活、事件等，需要在应用启动时初始化SDK，这个时候需要传入当前渠道，以便数据的统计。

由于最开始是用脚本一个个打包，一直想解决打包过慢的问题，但是网上大多教程是基于命令行参数或flavor，实质上并没有根本解决打包效率的问题。直到发现了文章的主角 walle。

应用解决方案 walle

walle是美团开源的一个打包插件，这里就不做介绍了，传送门。

flutter插件

由于源码是Android端的，就想着写一个Flutter插件吧。代码也很简单，已经上传到pub仓库。使用步骤可以参考 Github | Pub仓库。

插件使用

参考example

插件源码 在 android/build.gradle 文件中添加依赖

buildscript {
    repositories {
        // 不加这个找不到walle依赖
        maven {
            url 'https://maven.aliyun.com/repository/jcenter'
        }
        maven {
            url 'https://maven.aliyun.com/repository/google'
        }
        google()
        mavenCentral()
    }
}

rootProject.allprojects {
    repositories {
        // 同上
        maven {
            url 'https://maven.aliyun.com/repository/jcenter'
        }
        maven {
            url 'https://maven.aliyun.com/repository/google'
        }
        google()
        mavenCentral()
    }
}

// ...

// 末尾添加
dependencies {
    implementation 'com.meituan.android.walle:library:1.1.7'
}

Android端注册文件（android/src/main/java/net/niuxiaoer/package_by_walle/PackageByWallePlugin.java）

import com.meituan.android.walle.WalleChannelReader;


/** PackageByWallePlugin */
public class PackageByWallePlugin implements FlutterPlugin, MethodCallHandler {
  /// The MethodChannel that will the communication between Flutter and native Android
  ///
  /// This local reference serves to register the plugin with the Flutter Engine and unregister it
  /// when the Flutter Engine is detached from the Activity
  private MethodChannel channel;
  private Context applicationContext;

  @Override
  public void onAttachedToEngine(@NonNull FlutterPluginBinding flutterPluginBinding) {
    this.applicationContext = flutterPluginBinding.getApplicationContext();
    channel = new MethodChannel(flutterPluginBinding.getBinaryMessenger(), "package_by_walle");
    channel.setMethodCallHandler(this);
  }

  @Override
  public void onMethodCall(@NonNull MethodCall call, @NonNull Result result) {
    if (call.method.equals("getPackingChannel")) {
      try {
        // 这里调用walle的方法
        String channel = WalleChannelReader.getChannel(this.applicationContext);
        result.success(channel);
      } catch(Exception e) {
        result.success("unknown");
      }
    }  else if (call.method.equals("getPackingInfo")) {
      ChannelInfo channelInfo = WalleChannelReader.getChannelInfo(this.applicationContext);
      if (channelInfo != null) {
        Map<String, String> extraInfo = channelInfo.getExtraInfo();
        result.success(extraInfo);
      } else {
        result.success(null);
      }
    } else {
      result.notImplemented();
    }
  }

  @Override
  public void onDetachedFromEngine(@NonNull FlutterPluginBinding binding) {
    channel.setMethodCallHandler(null);
  }
}

iOS端注册文件（ios/Classes/PackageByWallePlugin.m）

@implementation PackageByWallePlugin
+ (void)registerWithRegistrar:(NSObject<FlutterPluginRegistrar>*)registrar {
  FlutterMethodChannel* channel = [FlutterMethodChannel
      methodChannelWithName:@"package_by_walle"
            binaryMessenger:[registrar messenger]];
  PackageByWallePlugin* instance = [[PackageByWallePlugin alloc] init];
  [registrar addMethodCallDelegate:instance channel:channel];
}

- (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
  if ([@"getPackingChannel" isEqualToString:call.method]) {
    result(@"AppStore");
  } else {
    result(FlutterMethodNotImplemented);
  }
}

@end

dart文件（lib/package_by_walle.dart）

class PackageByWalle {
  static const MethodChannel _channel = MethodChannel('package_by_walle');

  static Future get getPackingChannel async {
    final String? version = await _channel.invokeMethod('getPackingChannel');
    return version;
  }

  static Future?> get getPackingInfo async {
    if (Platform.isAndroid) {
      final Map? info = await _channel.invokeMethod('getPackingInfo');
      return info;
    } else {
      return null;
    }
  }
}

以往的解决方案

编写NodeJS脚本，通过修改配置文件一个一个渠道进行打包

提升

使用脚本的方式打一个渠道包需要3-4分钟，总共就需要等待半个多小时。现在一共只需要三分钟左右，节省了大量的时间，真香~

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