ReactJs

React Native Background Tasks: A Deep Dive

Posted on by thuan

React Native is a popular framework for building mobile applications using JavaScript and React. One of the challenges of mobile app development is dealing with background tasks, which are tasks that need to run even when the app is not in the foreground. In this article, we’ll take a deep dive into React Native background tasks and how to handle them.

Background Tasks in React Native

Background tasks in React Native refer to tasks that run in the background while the app is not in the foreground. These tasks can be used for a variety of purposes, such as fetching data, sending notifications, or updating the app’s state.

React Native provides several ways to handle background tasks, including:

  • Background fetch: This API allows you to fetch data in the background at regular intervals, even when the app is not running.
  • Headless JS: This API allows you to run JavaScript code in the background, even when the app is not running. This is useful for performing tasks such as sending notifications or updating the app’s state.
  • Background geolocation: This API allows you to track the user’s location in the background, even when the app is not running.

Now, let’s take a deeper look at each of these APIs.

Background Fetch

The BackgroundFetch API allows you to fetch data in the background at regular intervals, even when the app is not running. This is useful for fetching data that needs to be updated regularly, such as news articles or weather forecasts.

To use the BackgroundFetch API, you need to install the react-native-background-fetch library. Once installed, you can register a task to run at regular intervals using the registerTaskAsync() method.

Here’s an example:

javascript
import BackgroundFetch from 'react-native-background-fetch';

function fetchData() {
  // Fetch data here
}

BackgroundFetch.configure({
  minimumFetchInterval: 15, // Fetch data every 15 minutes
}, () => {
  fetchData();
  BackgroundFetch.finish();
});

BackgroundFetch.registerTaskAsync('fetchData', {
  minimumInterval: 15, // Fetch data every 15 minutes
  stopOnTerminate: false, // Keep fetching data even when the app is terminated
  startOnBoot: true, // Start fetching data when the device boots up
});

In this example, we configure the BackgroundFetch API to fetch data every 15 minutes. We then register a task called “fetchData” to run at the specified interval.

Headless JS

The Headless JS API allows you to run JavaScript code in the background, even when the app is not running. This is useful for performing tasks such as sending notifications or updating the app’s state.

To use the Headless JS API, you need to create a separate JavaScript file that contains the code you want to run in the background. You then register the file as a task using the registerHeadlessTask() method.

Here’s an example:

Create a file called “backgroundTask.js” with the following code:

java
module.exports = async (taskData) => {
  // Do something in the background
};

In your main app file, register the background task like this:

javascript
import { AppRegistry } from 'react-native';
import backgroundTask from './backgroundTask';

AppRegistry.registerHeadlessTask('backgroundTask', () => backgroundTask);

In this example, we create a file called “backgroundTask.js” that exports a function to be run in the background. We then register the function as a headless task using the registerHeadlessTask() method.

Background Geolocation

The Background Geolocation API allows you to track the user’s location in the background, even when the app is not running. This is useful for tracking the user’s movements or providing location-based notifications.

To use the Background Geolocation API, you need

To use the Background Geolocation API, you need to install the react-native-background-geolocation library. Once installed, you can start tracking the user’s location using the start() method.

Here’s an example:

php
import BackgroundGeolocation from 'react-native-background-geolocation';

BackgroundGeolocation.configure({
  desiredAccuracy: BackgroundGeolocation.HIGH_ACCURACY,
  stationaryRadius: 50,
  distanceFilter: 50,
  notificationTitle: 'Background tracking',
  notificationText: 'enabled',
  debug: true,
  startOnBoot: true,
  stopOnTerminate: false,
  locationProvider: BackgroundGeolocation.ACTIVITY_PROVIDER,
  interval: 10000,
  fastestInterval: 5000,
  activitiesInterval: 10000,
  stopOnStillActivity: false,
  url: 'http://yourserver.com',
  httpHeaders: {
    'X-FOO': 'bar'
  },
  // customize post properties
  postTemplate: {
    lat: '@latitude',
    lon: '@longitude',
    foo: 'bar' // you can also add your own properties
  }
});

BackgroundGeolocation.start();

In this example, we configure the Background Geolocation API to track the user’s location using high accuracy. We also configure it to send location updates to a server using HTTP POST requests.

Conclusion

In this article, we’ve taken a deep dive into React Native background tasks and how to handle them. We’ve looked at three APIs for handling background tasks: BackgroundFetch, Headless JS, and Background Geolocation. By using these APIs, you can create mobile apps that can perform tasks in the background, even when the app is not in the foreground. This can be incredibly useful for providing a seamless user experience and enhancing the functionality of your app.

0368826868