index.js

/**
 * @format
 */

import { AppRegistry } from 'react-native';
import 'react-native-gesture-handler';
import 'react-native-screens';
import 'react-native-safe-area-context';
import App from './App';
import BackgroundGeolocation from './Helpers/react-native-background-geolocation';
import BackgroundFetch from 'react-native-background-fetch';
import { name as appName } from './app.json';

AppRegistry.registerComponent(appName, () => App);


const BackgroundGeolocationHeadlessTask = async (event) => {
    let params = event.params;
    console.log('[BackgroundGeolocation HeadlessTask] -', event.name, params);

    switch (event.name) {
        case 'heartbeat':
            /**
            * Enable this block to execute #getCurrentPosition in headless heartbeat event (will consume more power)
            */
            // Use await for async tasks
            const location = await BackgroundGeolocation.getCurrentPosition({
                samples: 2,
                persist: true,
                extras: {
                    event: 'heartbeat',
                    headless: true
                }
            });
            console.log('[BackgroundGeolocation HeadlessTask] - getCurrentPosition:', location);
            break;
        case 'authorization':
            BackgroundGeolocation.setConfig({
                url:'https://tracker.transistorsoft.com/api/locations'
            });
            break;
    }
}


BackgroundGeolocation.registerHeadlessTask(BackgroundGeolocationHeadlessTask);

/**
* BackgroundFetch Headless JS Task.
* For more information, see:  https://github.com/transistorsoft/react-native-background-fetch#config-boolean-enableheadless-false
*/
const BackgroundFetchHeadlessTask = async (event) => {
    console.log('[BackgroundFetch HeadlessTask] start', event.taskId);

    if (event.taskId == 'react-native-background-fetch') {
        const location = await BackgroundGeolocation.getCurrentPosition({
            samples: 2,
            extras: {
                event: 'background-fetch',
                headless: true
            }
        });
        console.log('[BackgroundFetch] getCurrentPosition: ', location);

        /*
        await BackgroundFetch.scheduleTask({
          taskId: 'com.transistorsoft.customtask',
          delay: 5000,
          stopOnTerminate: false,
          enableHeadless: true,
          forceAlarmManager: true
        });
        */
    }
    // Important:  await asychronous tasks when using HeadlessJS.
    /* DISABLED
    const location = await BackgroundGeolocation.getCurrentPosition({persist: false, samples: 1});
    console.log('- current position: ', location);
    // Required:  Signal to native code that your task is complete.
    // If you don't do this, your app could be terminated and/or assigned
    // battery-blame for consuming too much time in background.
    */
    console.log('[BackgroundFetch HeadlessTask] finished');

    BackgroundFetch.finish(event.taskId);
}


// Register your BackgroundFetch HeadlessTask
BackgroundFetch.registerHeadlessTask(BackgroundFetchHeadlessTask);