HSP

A Harmony Shared Package (HSP) is a dynamic shared package that can contain code, C++ libraries, resource files, and configuration files (also called profiles) and allows for code and resource sharing within an application (called the host application). An HSP is released with the Application Package (App Pack) of the host application, shares a process with the host application, and has the same bundle name and lifecycle as the host application.

NOTE

As the inter-application HSP is not supported yet, unless otherwise specified, the HSP refers to the intra-application HSP.

When to Use

• By storing code and resource files shared by multiple HAPs/HSPs in one place, the HSP significantly improves the reusability and maintainability of the code and resource files. Better yet, because only one copy of the HSP code and resource files is retained during building and packaging, the size of the application package is effectively controlled.

• The HSP is loaded on demand during application running, which helps improve application performance.

Constraints

• An HSP must be installed and run with the HAP that depends on it. It cannot be installed or run independently on a device. The version of an HSP must be the same as that of the HAP.
• No UIAbility or ExtensionAbility can be declared in the configuration file of an HSP.
• An HSP can depend on other HARs or HSPs, but does not support cyclic dependency or dependency transfer.

Creating an HSP

Create an HSP module in DevEco Studio. In this example, an HSP module named library is created. The basic project directory structure is as follows:

library
├── src
│   └── main
│       ├── ets
│       │   ├── pages
│       │   └── index.ets
│       ├── resources
│       └── module.json5
└── oh-package.json5

Developing an HSP

You can export the ArkUI components, APIs, and other resources of an HSP for other HAPs or HSPs in the same application to reference.

Exporting ArkUI Components

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

// library/src/main/ets/components/MyTitleBar.ets
@Component
export struct MyTitleBar {
  build() {
    Row() {
      Text($r('app.string.library_title'))
        .id('library')
        .fontFamily('HarmonyHeiTi')
        .fontWeight(FontWeight.Bold)
        .fontSize(32)
        .fontColor($r('app.color.text_color'))
    }
    .width('100%')
  }
}

In the entry point file index.ets, declare the APIs to be exposed.

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

Exporting TS Classes and Methods

Use export to export TS classes and methods. The sample code is as follows:

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

export function add(a: number, b: number): number {
  return a + b;
}

export function minus(a: number, b: number): number {
  return a - b;
}

In the entry point file index.ets, declare the APIs to be exposed.

// library/src/main/ets/index.ets
export { Log, add, minus } from './utils/test';

Exporting Native Methods

The HSP can contain .so files compiled in C++. The HSP indirectly exports the native method in the .so file. In this example, the multi API in the liblibrary.so file is exported.

// library/src/main/ets/utils/nativeTest.ts
import native from 'liblibrary.so';

export function nativeMulti(a: number, b: number): number {
  let result: number = native.multi(a, b);
  return result;
}

In the entry point file index.ets, declare the APIs to be exposed.

// library/src/main/ets/index.ets
export { nativeMulti } from './utils/nativeTest';

Accessing Resources in an HSP Through $r

More often than not, you may need to use resources, such as strings and images, in components. For components in an HSP, such resources are typically placed in the HSP package, rather than in the package where the HSP is invoked, for the purpose of complying with the principle of high cohesion and low coupling.

In a project, application resources are referenced in the $r/$rawfile format. You can use $r/$rawfile to access resources in the resources directory of the current module. For example, you can use $r("app.media.example") to access the src/main/resources/base/media/example.png image stored in the resources directory. For details about how to use $r/$rawfile, see Resource Access: Application Resources.

To avoid reference errors, do not use relative paths. For example, if you use Image("../../resources/base/media/example.png"), the image actually used will be the one in the directory of the module that invokes the HSP. That is, if the module that invokes the HSP is entry, then the image used will be entry/src/main/resources/base/media/example.png.

// library/src/main/ets/pages/Index.ets
// Correct
Image($r('app.media.example'))
  .id('example')
  .borderRadius('48px')
// Incorrect
Image("../../resources/base/media/example.png")
  .id('example')
  .borderRadius('48px')

Exporting Resources from HSP

When resources in an HSP need to be exported for cross-package access, it is recommended that a resource manager class be implemented to encapsulate the exported resources. In this way:

• You can keep resources well under your control, eliminating the need for exporting resources that do not need to be exposed.
• The invoking module does not need to be aware of the internal resource names of the HSP, or make adaptation to changes in these internal resource names.

The implementation is as follows:

The implementation is as follows:

// library/src/main/ets/ResManager.ets
export class ResManager{
  static getPic(): Resource{
    return $r('app.media.pic');
  }
  static getDesc(): Resource{
    return $r('app.string.shared_desc');
  }
}

In the entry point file index.ets, declare the APIs to be exposed.

// library/src/main/ets/index.ets
export { ResManager } from './ResManager';

Using an HSP

You can reference APIs in an HSP and and implement page redirection in the HSP through page routing.

Referencing APIs

To use APIs in the HSP, first configure the dependency on the HSP in the oh-package.json5 file of the module that needs to call the APIs (called the invoking module). You can then call the external APIs of the HSP in the same way as calling the APIs in the HAR. In this example, the external APIs are the following ones exported from library:

// library/src/main/ets/index.ets
export { Log, add, minus } from './utils/test';
export { MyTitleBar } from './components/MyTitleBar';
export { ResManager } from './ResManager';
export { nativeMulti } from './utils/nativeTest';

The APIs can be used as follows in the code of the invoking module:

// entry/src/main/ets/pages/index.ets
import { Log, add, MyTitleBar, ResManager, nativeMulti } from 'library';
import { BusinessError } from '@ohos.base';
import Logger from '../logger/Logger';
import router from '@ohos.router';

const TAG = 'Index';

@Entry
@Component
struct Index {
  @State message: string = '';

  build() {
    Column() {
      List() {
        ListItem() {
          MyTitleBar()
        }
        .margin({ left: '35px', top: '32px' })

        ListItem() {
          Text(this.message)
            .fontFamily('HarmonyHeiTi')
            .fontSize(18)
            .textAlign(TextAlign.Start)
            .width('100%')
            .fontWeight(FontWeight.Bold)
        }
        .width('685px')
        .margin({ top: 30, bottom: 10 })

        ListItem() {
          // Resource object returned by ResManager, which can be passed to a component for direct use or be extracted.
          Image(ResManager.getPic())
            .id('image')
            .borderRadius('48px')
        }
        .width('685px')
        .margin({ top: 10, bottom: 10 })
        .padding({ left: 12, right: 12, top: 4, bottom: 4 })

        ListItem() {
          Text($r('app.string.add'))
            .fontSize(18)
            .textAlign(TextAlign.Start)
            .width('100%')
            .fontWeight(500)
            .height('100%')
        }
        .id('add')
        .borderRadius(24)
        .width('685px')
        .height('84px')
        .backgroundColor($r('sys.color.ohos_id_color_foreground_contrary'))
        .margin({ top: 10, bottom: 10 })
        .padding({ left: 12, right: 12, top: 4, bottom: 4 })
        .onClick(() => {
          Log.info('add button click!');
          this.message = 'result: ' + add(1, 2);
        })

        ListItem() {
          Text($r('app.string.get_string_value'))
            .fontSize(18)
            .textAlign(TextAlign.Start)
            .width('100%')
            .fontWeight(500)
            .height('100%')
        }
        .id('getStringValue')
        .borderRadius(24)
        .width('685px')
        .height('84px')
        .backgroundColor($r('sys.color.ohos_id_color_foreground_contrary'))
        .margin({ top: 10, bottom: 10 })
        .padding({ left: 12, right: 12, top: 4, bottom: 4 })
        .onClick(() => {
          // Obtain the context of the HSP module based on the current context, obtain the resourceManager object of the HSP module, and then call the API of resourceManager to obtain resources.
          getContext()
            .createModuleContext('library')
            .resourceManager
            .getStringValue(ResManager.getDesc())
            .then(value => {
              Logger.info(TAG, `getStringValue is ${value}`);
              this.message = 'getStringValue is ' + value;
            })
            .catch((err: BusinessError) => {
              Logger.info(TAG, `getStringValue promise error is ${err}`);
            });
        })

        ListItem() {
          Text($r('app.string.native_multi'))
            .fontSize(18)
            .textAlign(TextAlign.Start)
            .width('100%')
            .fontWeight(500)
            .height('100%')
        }
        .id('nativeMulti')
        .borderRadius(24)
        .width('685px')
        .height('84px')
        .backgroundColor($r('sys.color.ohos_id_color_foreground_contrary'))
        .margin({ top: 10, bottom: 10 })
        .padding({ left: 12, right: 12, top: 4, bottom: 4 })
        .onClick(() => {
          Log.info('nativeMulti button click!');
          this.message = 'result: ' + nativeMulti(3, 4);
        })
      }
      .alignListItem(ListItemAlign.Center)
    }
    .width('100%')
    .backgroundColor($r('app.color.page_background'))
    .height('100%')
  }
}

Redirecting to a Page

If you want to add a button in the entry module to jump to the menu page (library/src/main/ets/pages/menu.ets) in the library module, you can write the following code in the entry/src/main/ets/pages/Index.ets file of the entry module:

import { Log, add, MyTitleBar, ResManager, nativeMulti } from 'library';
import { BusinessError } from '@ohos.base';
import Logger from '../logger/Logger';
import router from '@ohos.router';

const TAG = 'Index';

@Entry
@Component
struct Index {
  @State message: string = '';

  build() {
    Column() {
      List() {
        ListItem() {
          Text($r('app.string.click_to_menu'))
            .fontSize(18)
            .textAlign(TextAlign.Start)
            .width('100%')
            .fontWeight(500)
            .height('100%')
        }
        .id('clickToMenu')
        .borderRadius(24)
        .width('685px')
        .height('84px')
        .backgroundColor($r('sys.color.ohos_id_color_foreground_contrary'))
        .margin({ top: 10, bottom: 10 })
        .padding({ left: 12, right: 12, top: 4, bottom: 4 })
        .onClick(() => {
          router.pushUrl({
            url: '@bundle:com.samples.hspsample/library/ets/pages/Menu'
          }).then(() => {
            console.log('push page success');
            Logger.info(TAG, 'push page success');
          }).catch((err: BusinessError) => {
            Logger.error(TAG, `pushUrl failed, code is ${err.code}, message is ${err.message}`);
          })
        })
      }
      .alignListItem(ListItemAlign.Center)
    }
    .width('100%')
    .backgroundColor($r('app.color.page_background'))
    .height('100%')
  }
}

The input parameter url of the router.pushUrl API is as follows:

'@bundle:com.samples.hspsample/library/ets/pages/Menu'

The url content template is as follows:

'@bundle:bundleName/moduleName/path/page file name (without the extension .ets)'

Going Back to Previous Page with Router

You can use the router.back method to go back, from a page in the HSP, to the previous page, under the prerequisite that the target page is in the redirection path of the source page.

import router from '@ohos.router';

@Entry
@Component
struct Index3 { // The path is library/src/main/ets/pages/Back.ets.
  @State message: string = 'HSP back page';

  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontFamily('HarmonyHeiTi')
          .fontWeight(FontWeight.Bold)
          .fontSize(32)
          .fontColor($r('app.color.text_color'))
          .margin({ top: '32px' })
          .width('624px')

        Button($r('app.string.back_to_HAP'))
          .id('backToHAP')
          .fontFamily('HarmonyHeiTi')
          .height(48)
          .width('624px')
          .margin({ top: 550 })
          .type(ButtonType.Capsule)
          .borderRadius($r('sys.float.ohos_id_corner_radius_button'))
          .backgroundColor($r('app.color.button_background'))
          .fontColor($r('sys.color.ohos_id_color_foreground_contrary'))
          .fontSize($r('sys.float.ohos_id_text_size_button1'))
            // Bind click events.
          .onClick(() => {
            router.back({ // Go back to the HAP page.
              url: 'pages/Index' // The path is entry/src/main/ets/pages/Index.ets.
            })
          })

        Button($r('app.string.back_to_HSP'))
          .id('backToHSP')
          .fontFamily('HarmonyHeiTi')
          .height(48)
          .width('624px')
          .margin({ top: '4%' , bottom: '6%' })
          .type(ButtonType.Capsule)
          .borderRadius($r('sys.float.ohos_id_corner_radius_button'))
          .backgroundColor($r('app.color.button_background'))
          .fontColor($r('sys.color.ohos_id_color_foreground_contrary'))
          .fontSize($r('sys.float.ohos_id_text_size_button1'))
            // Bind click events.
          .onClick(() => {
            router.back({ // Go back to the HSP page.
              url: '@bundle:com.samples.hspsample/library/ets/pages/Menu' // The path is library/src/main/ets/pages/Menu.ets.
            })
          })
      }
      .width('100%')
    }
    .backgroundColor($r('app.color.page_background'))
    .height('100%')
  }
}

The url parameter in the router.back method is described as follows:

• In this example, the URL for going back from the HSP page to the HAP page is as follows:

  'pages/Index'
  

  The url content template is as follows:

  'Page file name (without the extension .ets)
  

• To return to the HSP1 page after switching to the HSP2 page, the URL should be as follows:

  '@bundle:com.samples.hspsample/library/ets/pages/Menu'
  

  The url content template is as follows:

  '@bundle:bundleName/moduleName/path/page file name (without the extension .ets)'