Background Sync

This package doesn't manage background tasks — that's platform-specific. But OfflineManager is a standalone singleton that works outside React, so you can call it from any background task runner.

react-native-background-fetch

import BackgroundFetch from 'react-native-background-fetch';
import { OfflineManager } from '@mustafaaksoy41/react-native-offline-queue';

BackgroundFetch.configure({
  minimumFetchInterval: 15,
}, async (taskId) => {
  // Re-configure if the app was killed and relaunched
  await OfflineManager.configure({
    storageType: 'mmkv',
    onSyncAction: myApiHandler,
  });

  await OfflineManager.flushQueue();
  BackgroundFetch.finish(taskId);
});

expo-task-manager

import * as TaskManager from 'expo-task-manager';
import { OfflineManager } from '@mustafaaksoy41/react-native-offline-queue';

TaskManager.defineTask('OFFLINE_SYNC', async () => {
  await OfflineManager.configure({
    storageType: 'mmkv',
    onSyncAction: myApiHandler,
  });
  
  await OfflineManager.flushQueue();
  return BackgroundFetch.Result.NewData;
});

Important

If iOS killed and relaunched the app for a background task, OfflineManager.configure() must be called again before flushQueue(). The in-memory configuration is lost on app termination.

Why configure() again?

When iOS terminates and relaunches the app for a background task:

1. The React component tree is NOT mounted
2. OfflineProvider never renders
3. OfflineManager has no configuration

So you need to manually call configure() to set up the storage adapter and sync handler before flushing.