harmony 鸿蒙HAR

2023-06-24
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HAR

A Harmony Archive (HAR) is a static shared package that can contain code, C++ libraries, resources, and configuration files. It enables modules and projects to share code related to ArkUI components, resources, and more. Unlike a Harmony Ability Package (HAP), a HAR cannot be independently installed on a device. Instead, it can be referenced only as the dependency of an application module.

Creating a HAR Module

You can create a HAR module in DevEco Studio.

To better protect your source code, enable obfuscation for the HAR module so that DevEco Studio compiles, obfuscates, and compresses code during HAR building. > NOTE > > Obfuscation is only available for ArkTS projects in the stage model.

Whether obfuscation is enabled by default varies by version.

In API version 9, obfuscation is disabled by default, and can be enabled by setting artifactType to obfuscation in the build-profile.json5 file of the HAR module. The configuration is as follows:

  {
    "apiType": "stageMode",
    "buildOption": {
        "artifactType": "obfuscation"
    }
  }

The value options of artifactType are as follows, with the default value being original: - original: Code is not obfuscated. - obfuscation: Code is obfuscated using Uglify.

In API version 10, obfuscation is enabled by default, and can be set through the enable field under ruleOptions in the build-profile.json5 file of the HAR module. The configuration is as follows:

  {
    "apiType": "stageMode",
    "buildOption": {
    },
    "buildOptionSet": [
      {
        "name": "release",
        "arkOptions": {
          "obfuscation": {
            "ruleOptions": {
              "enable": true,
              "files": [
                "./obfuscation-rules.txt"
              ]
            },
            "consumerFiles": [
              "./consumer-rules.txt"
            ]
          }
        }
      },
    ],
    "targets": [
      {
        "name": "default"
      }
    ]
  }

Adaptation Guide

The artifactType field is forward compatible, and the original function is not affected. Yet, it is deprecated since API version 10, and you are advised to use the substitute as soon as possible.

Precautions for HAR Development

The HAR does not support the declaration of abilities and extensionAbilities in its configuration file.
The HAR does not support the declaration of pages in its configuration file.
The HAR does not support worker configuration under buildOption in the build-profile.json5 file.
The HAR of the FA model and that of the stage model cannot be referenced by each other.
The HAR of the stage model cannot reference content in the AppScope folder. This is because the content in the AppScope folder is not packaged into the HAR during compilation and building.

Exporting ArkUI Components, APIs, and Resources of the HAR

The index.ets file acts as the entry of the HAR export declaration file and is where the HAR exports APIs. This file is automatically generated by DevEco Studio by default. You can specify another file as the entry declaration file in the main field in the oh-package.json5 file of the module. The code snippet is as follows:

{
  "main": "index.ets"
}

Exporting ArkUI Components

Use export to export the ArkUI components. The code snippet is as follows:

// library/src/main/ets/components/MainPage/MainPage.ets
@Component
export struct MainPage {
  @State message: string = 'Hello World'
  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
    }
    .height('100%')
  }
}

In the index.ets file, declare the APIs that the HAR exposes to external systems. The code snippet is as follows:

// library/index.ets
export { MainPage } from './src/main/ets/components/MainPage/MainPage'

Exporting TS Classes and Methods

Use export to export TS classes and methods. Multiple TS classes and methods can be exported at the same time. The code snippet is as follows:

// library/src/main/ts/test.ets
export class Log {
    static info(msg: string) {
        console.info(msg);
    }
}

export function func() {
  return "har func";
}

export function func2() {
  return "har func2";
}

In the index.ets file, declare the APIs that the HAR exposes to external systems. The code snippet is as follows:

// library/index.ets
export { Log } from './src/main/ts/test'
export { func } from './src/main/ts/test'
export { func2 } from './src/main/ts/test'

Resources

Resources are packed into the HAR when it is being compiled and packaged. During compilation and building of a HAP, DevEco Studio collects resource files from the HAP module and its dependent modules. If the resource files of different modules have the same name, DevEco Studio overwrites the resource files based on the following priorities (in descending order): - AppScope (only for the stage model of API version 9) - Modules in the HAP file - If resource conflicts occur between dependent HAR modules, they are overwritten based on the dependency sequence. (The module that is higher in the dependency sequence list has higher priority.)

Referencing ArkUI Components, APIs, and Resources in the HAR

To start with, configure dependency on the HAR.

Reference ArkUI Components in the HAR

After configuring the dependency on the HAR, you can reference ArkUI components exported from the HAR by using import. The code snippet is as follows:

// entry/src/main/ets/pages/index.ets
import { MainPage } from "library"

@Entry
@Component
struct Index {
  @State message: string = 'Hello World'
  build() {
    Row() {
      // Reference the ArkUI component in the HAR.
      MainPage()
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
    }
    .height('100%')
  }
}

Referencing TS Classes and Methods in the HAR

To reference the TS classes and methods exported from the HAR, use import as follows:

// entry/src/main/ets/pages/index.ets
import { Log } from "library"
import { func } from "library"

@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        Button('Button')
          .onClick(()=>{
            // Reference TS classes and methods in the HAR.
            Log.info("har msg");
            func();
        })
      }
      .width('100%')
    }
    .height('100%')
  }
}

Referencing Resources in the HAR

Use $r to reference resources in the HAR. For example, add the name: hello_har string (defined in the string.json file) and icon_har.png image to the src/main/resources directory of the HAR module, and then reference the string and image in the entry module. The code snippet is as follows:

// entry/src/main/ets/pages/index.ets
@Entry
@Component
struct Index {
  build() {
    Row() {
      Column() {
        // Reference the string in the HAR.
        Text($r("app.string.hello_har"))
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
        // Reference the image in the HAR.
        Image($r("app.media.icon_har"))
      }
      .width('100%')
    }
    .height('100%')
  }
}