With the continuous development of HarmonyOS applications, the functions of the applications will become more and more abundant. In fact, 80% of users will be concentrated on 20% of the features, and the remaining functions may only be aimed at some users.
When users download an application, if the application contains a large number of functions and resources, it may cause too long to download; if the application contains many functions that are not commonly used or only required by a specific user group, these functions will occupy the storage space of the user's device; if the application is large, the startup and operation speed may be affected.
In order to avoid the user's first download of the application is too long and taking up too much user space, HarmonyOS SDKApplication Market Services(Store Kit) providesProduct features distributed on demandThe ability to provide dynamic distribution and resource splitting, supports users to dynamically download the enhanced features they need on demand, reduces the distribution cost of developers' applications, and focuses on maintaining and distributing functional modules that users actually need, helping to improve distribution efficiency.
Basic concepts
Distribute on demand: An application is packaged into multiple installation packages, which contains all application code and static resources. The applications downloaded by users from the application market only contain installation packages for basic functions. When users need to use enhanced functions, the corresponding installation package will be downloaded from the server to the device.
Development steps
Get module installation information
1. Import the moduleInstallManager module and related public modules.
import { moduleInstallManager } from '@';
2. Construct parameters.
The entry parameter is the name of the module to be queried.
const moduleName: string = 'AModule';
3. Call the getInstalledModule method and pass the parameters constructed in step 2 into the getInstalledModule method in the module.
const moduleInfo: = (moduleName);
Create a request instance that loads on demand
1. Import the moduleInstallManager module and related public modules.
import { moduleInstallManager } from '@';
import type { common } from '@';
2. Construct parameters.
The entry parameter is the context of the current application, and only supports UIAbilityContext and ExtensionContext types contexts. The context of the UIAbilityContext type is to verify whether the current application is in the foreground. If it is not in the foreground, it will be denied to call.
const context: | = getContext(this) as ;
3. Call the createModuleInstallRequest method and pass the parameters constructed in step 2 into the createModuleInstallRequest method in the module in sequence.
const myModuleInstallProvider: = new ();
const myModuleInstallRequest: = (context);
Requesting an interface to load on demand
1. Import the moduleInstallManager module and related public modules.
import type { common } from '@';
import { hilog } from '@';
import { moduleInstallManager } from '@';
2. Construct parameters.
The entry parameter is the module name that is currently loaded as needed.
const moduleNameA: string = 'AModule';
const moduleNameB: string = 'BModule';
3. Call the addModule method in ModuleInstallRequest and pass the parameters constructed in step 2 into the addModule method in the module in sequence.
let myModuleInstallRequest: ;
try {
const myModuleInstallProvider: = new ();
const context: | = getContext(this) as ;
myModuleInstallRequest = (context);
const aResult: = (moduleNameA);
const bResult: = (moduleNameB);
(0, 'TAG', 'aResult:' + aResult + ' bResult:' + bResult);
} catch (error) {
(0, 'TAG', `addModule is ${}, message is ${}`);
}
4. Call the fetchModules method and pass the myModuleInstallRequest in step three into the fetchModules method in the module.
try {
(myModuleInstallRequest)
.then((data: ) => {
(0, 'TAG', 'Succeeded in fetching Modules data.');
})
} catch (error) {
(0, 'TAG', `fetching Modules is ${}, message is ${}`);
}
Using dynamic modules
If application A is composed of two packages, where entry is the basic package and AModulelib extension is the function package (please refer to the creation methodApplication package development and use). Downloading and installing through the application market will only download the entry package. In the entry package, you can dynamically download the AModulelib package through the fetchModules interface and useDynamic importTechnology calls methods and components in AModulelib.
The main implementations in AModulelib are as follows:
- Define the add method and the DateComponent component in the dynamic module AModulelib. where the add method is used to calculate addition, and the DateComponent is used to display text.
Definition is as follows:
export function add(a:number, b:number) {
return a + b;
}
Definition is as follows:
@Component
struct DateComponent {
build() {
Column() {
Text('I am a component in AModulelib')
.margin(10);
}
.width(300).backgroundColor();
}
}
@Builder
export function showDateComponent() {
DateComponent()
}- Export the add method and showDateComponent method in AModulelib/ of AModulelib.
export { add } from './src/main/ets/utils/Calc';
export { showDateComponent } from './src/main/ets/components/DateComponent';
The main implementations in entry are as follows:
- In the entry basic module, add dynamic dependency configuration. DynamicDependencies are used in entry's oh-package.json5 to dynamically rely on the AModulelib module.
{
"dynamicDependencies": {
"AModulelib": "file:../AModulelib"
}
}
- Use the methods and components in the dynamic module AModulelib module in the entry. Before calling the functions in AModulelib, you need to determine whether AModulelib has been loaded. Please refer to it if it is not loaded.Requesting an interface to load on demandComplete loading.
import { moduleInstallManager } from '@';
import { hilog } from '@';
import { BusinessError, Callback } from '@';
import { common } from '@';
import { promptAction } from '@';
const TAG: string = 'TAG';
@Entry
@Component
struct Index {
@BuilderParam AModulelibComponent: Function;
@State countTotal: number = 0;
@State isShow: boolean = false;
build() {
Row() {
Column() {
Button(`Call add function in incremental module: 3+6`)
.onClick(() => {
(() => {
import('AModulelib').then((ns: ESObject) => {
= (3, 6);
}).catch((error: BusinessError) => {
(0, 'TAG', `add is ${}, message is ${}`);
})
})
});
Text('Computation result:' + )
.margin(10);
Button(`Calling the showDateComponent function in the incremental module`)
.onClick(() => {
(() => {
import('AModulelib').then((ns: ESObject) => {
= ;
= true;
}).catch((error: BusinessError) => {
(0, 'TAG', `showDateComponent is ${}, message is ${}`);
})
})
}).margin({
top: 10, bottom: 10
});
if () {
()
}
}
.width('100%')
}
.height('100%')
}
private showToastInfo(msg: string) {
({
message: msg,
duration: 2000
});
}
/**
* Check whether the AModulelib package is loaded
*
* @param successCallBack callback
*/
private initAModulelib(successCallBack: Callback<void>): void {
try {
const result: = ('AModulelib');
if (result?.installStatus === ) {
(0, TAG, 'AModulelib installed');
successCallBack && successCallBack();
} else {
// The AModulelib module is not installed, you need to call fetchModules to download the AModulelib module.
(0, TAG, 'AModulelib not installed');
('AModulelib', successCallBack)
}
} catch (error) {
(0, 'TAG', `getInstalledModule is ${}, message is ${}`);
}
}
/**
* Add listening events
*
* @param successCallBack callback
*/
private onListenEvents(successCallBack: Callback<void>): void {
const timeout = 3 * 60; //Units of seconds, the default maximum listening time is 30min (that is, 30*60 seconds)
('moduleInstallStatus', (data: ) => {
// Return to success
if ( === .INSTALL_SUCCESSFUL) {
successCallBack && successCallBack();
('install success');
}
}, timeout)
}
/**
* Load the specified package
*
* @param moduleName The name of the installation package that needs to be loaded
* @param successCallBack callback
*/
private fetchModule(moduleName: string, successCallBack: Callback<void>) {
try {
(0, TAG, 'handleFetchModules start');
const context = getContext(this) as;
const moduleInstallProvider: =
new ();
const moduleInstallRequest: =
(context);
if (!moduleInstallRequest) {
(0, TAG, 'moduleInstallRequest is empty');
return;
}
(moduleName);
(moduleInstallRequest)
.then((data: ) => {
(0, TAG, 'Succeeded in fetching Modules result.');
if ( === ) {
(successCallBack)
} else {
(0, TAG, 'fetchModules failure');
}
})
.catch((error: BusinessError) => {
(0, 'TAG', `fetchModules is ${}, message is ${}`);
})
} catch (error) {
(0, 'TAG', `handleFetchModules is ${}, message is ${}`);
}
}
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