How can developers can automatically restart a HarmonyOS app after clearing all app data?

#harmonyos #apprecoveryapi #apprestartafterdataclear #clearupapplicationdata

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Question

How can developers automatically restart a HarmonyOS app after clearing all app data, given that ApplicationContext.clearUpApplicationData exits the app without triggering a callback?

Short Answer

ApplicationContext.clearUpApplicationData clears all app data and directly exits the app, so it does not provide a callback for when data is successfully cleared. To achieve the requirement, you need to:

Use appRecovery API to configure app restart behavior.
Manually implement cache/data cleanup with the fs module if you need a completion timing.
Trigger appRecovery.restartApp() only after your cleanup logic completes, instead of relying on clearUpApplicationData.

Solution Code Examples:

1.Configure App Recovery in AbilityStage

   // AbilityStage
   import appRecovery from '@ohos.app.ability.appRecovery';
   import AbilityStage from '@ohos.app.ability.AbilityStage';

   export default class MyAbilityStage extends AbilityStage {
     onCreate() {
       appRecovery.enableAppRecovery(
         appRecovery.RestartFlag.ALWAYS_RESTART,
         appRecovery.SaveOccasionFlag.SAVE_WHEN_ERROR,
         appRecovery.SaveModeFlag.SAVE_WITH_FILE
       );

       let want = {
         bundleName: 'com.example.test',
         abilityName: 'EntryAbility'
       }
       appRecovery.setRestartWant(want)
     }
   }

2.Configure Ability as startup

   "module": {
     "name": "entry",
     "srcEntry": "./ets/AbilityStage/AbilityStage.ets",
     ...
   },
   "abilities": [
     {
       "name": "EntryAbility",
       "recoverable": true,
       ...
     }
   ]

3.Restart App on Button Click

   Button('Restart App')
     .onClick(() => {
       appRecovery.restartApp();
     })

4.Manually Clear Cache with fs (timing control)

   import { storageStatistics } from '@kit.CoreFileKit';
   import fs from '@ohos.file.fs';
   import { Context } from '@kit.AbilityKit';
   import { BusinessError } from '@ohos.base';

   @Entry
   @Component
   struct Clearcache {
     build() {
       Button('Clear cache')
         .onClick(() => {
           const context: Context = getContext(this);
           let cacheDir = context.cacheDir;

           fs.listFile(cacheDir).then((filenames) => {
             for (let i = 0; i < filenames.length; i++) {
               let dirPath = cacheDir + filenames[i];
               try {
                 let isDirectory = fs.statSync(dirPath).isDirectory();
                 if (isDirectory) {
                   fs.rmdirSync(dirPath);
                 } else {
                   fs.unlink(dirPath).then(() => {
                     console.info('remove file succeed');
                   }).catch((err: BusinessError) => {
                     console.error("remove file failed: " + err.message);
                   });
                 }
               } catch (e) {
                 console.log(e);
               }
             }
             // ✅ Restart app after cleanup completes
             appRecovery.restartApp();
           })
         })
     }
   }

Applicable Scenarios

When you want the application to restart automatically after clearing app cache or local data.
When you need precise control of the timing after data deletion (e.g., clear user sessions, local storage, or cache).
When clearUpApplicationData exits the app immediately and you require a custom solution that ensures restart.
Suitable for HarmonyOS applications that must ensure recovery/restart flow after cleanup.