Headless Javascript in React Native: Ultimate tool for building scalable apps with a 100% increase in performance

Headless Javascript in a React Native app is a way to run JavaScript in the background, without a user interface. It is used to perform not-interrupted tasks. For example: checking for new data, sending notifications, or tracking the user’s location. 

In Headless JavaScript the code is executed without the need for a window to be displayed. Headless JavaScript is often used to automate tasks, build server-side applications, run JavaScript in the cloud, or build command-line tools. It can also be used to build headless content management systems (CMSs) or run JavaScript on devices like Raspberry Pi or Arduino. Headless JavaScript allows developers to take advantage of the full power of JavaScript, without being limited by the constraints of a user interface (UI). You can find step-by-step examples here.

Here are a few examples of how it is being used in React Native:

• To build backend services that can be accessed by multiple platforms. This allows for a unified and consistent user experience across different platforms. Such uses can be found in Firebase, which offers real-time databases, authentication, and storage services. One more example is GraphQL. Then, Back4App is a platform that allows developers to easily create, deploy, and manage a backend service. All of them are easily integrated into a React Native app. A Windows Task Scheduler is a good example. find a brief explanation here. 

• To automate tasks, such as testing and building processes. This saves time and improves the overall quality of the product. One example is a task management app. Headless JavaScript could be used to automatically schedule and remind users of upcoming tasks, as well as tracking progress on completed tasks. Another example could be a financial management app that uses headless JavaScript to automatically categorize and track expenses, or a social media app that uses headless JavaScript to automatically curate a user’s feed based on their interests and behavior. Click here, find more to explore about automated code review: improve your code review process by automatizing it.

• To build serverless apps and services. This enables a more flexible and cost-effective way to build and deploy apps, as well as improved scalability and reliability. An example is a chat app that uses Firebase Cloud Functions to handle server-side logic and Firebase Realtime Database to store and retrieve data. Another example is a survey app that uses AWS Lambda to process survey responses and AWS DynamoDB to store the data, using headless JavaScript to handle the communication between the front-end of the app and the serverless back-end.

• To build Internet of Things (IoT) apps in React Native. This allows for real-time data collection and processing, as well as the ability to control IoT-devices remotely. An example of it is a smart home app that allows users to control and monitor their devices [thermostats, lighting, and security systems]. The app could use headless JavaScript to handle the communication between the front-end of the app and the back-end, which would use IoT protocols like MQTT or Zigbee. Another example is an industrial IoT app which uses IoT protocols like Modbus or OPC-UA to communicate with industrial equipment or machinery.

• To build AI and machine learning [ML] apps. Think of more sophisticated and intelligent apps, such as image recognition, natural language processing, and predictive analytics. Examples of this could be apps that use Headless JavaScript to communicate with a server-side ML model, which handles image recognition or natural language processing. The React Native app would handle the user interface and send data to the server-side model for processing, and then receive the processed data back from the model to be displayed to the user. 

If you want to keep on exploring about AI, just click on Machine learning and artificial intelligence approaches: how they can be game-changing for businesses

This is only a sneak peek of how headless JavaScript is being used in React Native to build innovative applications and services. The possibilities are virtually endless, and as the technology continues to evolve, new use cases and applications will likely emerge. Check this post for the latest!!! 

Better performance: By offloading certain tasks to the background, headless JavaScript helps improve the overall performance of your application. Here we give you a few ways to do so:

• Using Web Workers in React Native:  React Native allows you to run JavaScript code in a web worker, which is a separate thread from the main UI thread. Web workers are a way to run JavaScript code in the background and communicate with the main thread using a message-passing API.  To use it, you can use the react-native-webview library. It allows you to create a web worker by running JavaScript code in a webview, which is a native component that can run web content. Here’s an example of how you might use it in a React Native app:

import React, { useState, useRef } from 'react';
import { View, Button } from 'react-native';
import { WebView } from 'react-native-webview';

const App = () => {
  const [result, setResult] = useState(null);
  const webViewRef = useRef();

  // Function to handle messages from the web worker
  const handleMessage = event => {
    const { data } = event.nativeEvent;
    setResult(data);
  };

  return (
    <View>
      <Button title="Run Code" onPress={() => webViewRef.current.injectJavaScript('runCode()')} />
      {result && <Text>{result}</Text>}
      <WebView
        ref={webViewRef}
        source={require('./worker.js')}
        onMessage={handleMessage}
        javaScriptEnabled
      />
    </View>
  );
};

export default App;

Here you will also find more examples of how to run Headless JS in React Native.

• Using requestIdleCallback in React Native:

‘requestIdleCallback’ is a method that allows you to schedule a function to be called during a browser’s idle period. In React Native, you can use the HeadlessJS module to run a task in the background, independent of the React Native JavaScript thread. To use requestIdleCallback in React Native, you would need to use HeadlessJS.start and pass in a callback function that uses requestIdleCallback. The callback function will be called during the browser’s idle period. If you need to move some steps back, don’t hesitate to visit this previous post: React Native Configuration: everything you need to know.

• Using setTimeout or setInterval in React Native: 

In React Native, you can use the built-in setTimeout and setInterval functions to schedule the execution of code at a later time. ‘setTimeout’ is used to execute a function after a specified amount of time has passed. For example: 

setTimeout(() => {
  console.log('Hello, World!');
}, 2000);

This will log “Hello, World!” to the console after 2 seconds. ‘setInterval’ is similar to ‘setTimeout’, but it will execute the function repeatedly at a specified interval. For example:

setInterval(() => {
  console.log('Hello, World!');
}, 2000);

This will log “Hello, World!” to the console every 2 seconds.

It’s important to note that both ‘setTimeout’ and ‘setInterval’ return a unique ID that you can use to clear the timeout or interval using ‘clearTimeout’ or ‘clearInterval’ function.

const intervalId = setInterval(() => {
  console.log('Hello, World!');
}, 2000);
// Later, to stop the interval:
clearInterval(intervalId);

A heads up! React Native uses a bridge to interact with the native APIs, so you might experience some delay when using these functions.

Improved efficiency: You can use the ‘react-native-background-task’ library, it allows you to run background tasks in your react native app, you can use this library to schedule tasks that will run in the background and retrieve the data from the websites you want to scrape. Find it in this 2023 post.

Keep it legal! 

It’s worth noting that whatever the solution you choose, scraping multiple websites at the same time might also be against the terms of service of some websites and could be illegal in some countries. Before scraping a website, you should check its terms of service and also respect the website’s rate limits to avoid overwhelming the server.

Headless JS Mastery: Proven Tips for Building Cutting-Edge Applications with React Native.

Increased scalability: Headless JavaScript allows you to build scalable applications that can handle a large number of tasks or requests without slowing down. This can help to improve performance and reduce the load on the main thread, allowing the application to handle more requests and perform more complex tasks. The following can be used to scale an app: performing background tasks, parallel processing, distributed computing, scraping or testing in React Native. You can also Increase flexibility, have a greater control and also enhance security [bear in mind that it’s not a silver bullet for securing your app.  Reinforce it with other security measures, such as input validation, encryption, and access controls].

Some tricks to get your hands busy!

One way to split a task using headless JavaScript in React Native is to use the ‘react-native-headless-js’ library, which allows you to run JavaScript code in a separate thread from the main UI thread. But, keep this in mind for a smooth sail, ‘react-native-headless-js’ library has been deprecated and is not actively maintained. Instead, you can use the ‘react-native-background-task’ library that allows you to run background tasks in your react native app and it’s actively maintained. Visit here to get it!

To use the ‘react-native-background-task’ library with headless JavaScript, you will first need to install the library by running ‘npm install react-native-background-task’ or ‘yarn add react-native-background-task’. Next, you will need to configure the library to run your headless JavaScript task by importing the library and setting it up in your app’s JavaScript code.

Here’s an example of how you might use react-native-background-task with headless JS:

• Import the library at the top of your JavaScript file:

import BackgroundTask from 'react-native-background-task'

• Register the headless task:

BackgroundTask.define(() => {
  // Your headless task code goes here
});

• Schedule the background task to run:

BackgroundTask.schedule();

You also need to configure your native projects to run background tasks:

For Android:

• Add this line in ‘android/app/src/main/java/com/[your-app-name]/MainApplication.java’

import com.reactnativebackgroundtask.BackgroundTaskPackage;

• Add this line in ‘android/app/src/main/java/com/[your-app-name]/MainApplication.java’

new BackgroundTaskPackage()

For iOS:

• Add this line in ‘ios/Podfile’

pod 'react-native-background-task', :path => '../node_modules/react-native-background-task'

• Run ‘pod install’
• Add this line in ‘ios/[YourProjectName]/AppDelegate.m’

#import "RNBackgroundTask.h"

• Add this line in ‘ios/[YourProjectName]/AppDelegate.m’

[RNBackgroundTask start];

Take heed of the fact that this is just a basic example and you’ll need to customize the code to suit your specific requirements!

Some caveats when using Headless JS in a React Native app:

In order to scale an application using headless technology, you will need to fully understand how the application is structured and the tasks it needs to perform. You will also need to painstakingly consider how the headless technology will be integrated into the React Native application and how it will interact with other parts of the app.

• It’s important to handle failures and retries properly, as Headless JS tasks may not always be able to complete successfully due to network or other issues.

• You should also be aware of the limitations of Headless JS. For example, it can’t access the device’s camera or microphone, and it can’t display UI elements or interact with the user.

• Finally, be aware that the behavior of Headless JS may vary across different devices and platforms, so it’s important to test your app thoroughly on a range of devices to ensure it works as expected.

But… Do you want to handle failures and retries like a whiz? Let’s get the ball rolling!

Yes, it can be challenging, however there are several tips and tricks you can use to improve your ability to handle them like a pro:

Implement Retry Logic: You can use it in your headless code to automatically retry a failed request after a certain amount of time. This can help ensure that the request is eventually successful and can reduce the impact of temporary failures.

Monitoring: Monitoring your headless services can give you visibility when failures occur and help you identify patterns or trends that may be causing them. This can help you find and fix bugs in advance.

Testing: Testing your headless code can help you identify potential issues early on and ensure that your code is robust enough to handle unexpected failures.

Fallback: You can use fallback options in your code to handle failures gracefully. For example, you can use cached data or display a default message if a request fails.

Error Handling: Properly handling errors in your code can help you identify and fix issues when they occur. You should also log the error message, error code and the stack trace for debugging purposes.

By implementing these strategies, you can hone in on your ability to handle headless failures and retries in React Native like a pro. Using Headless JS in React Native highlights the forward-thinking nature of programming and it allows developers to build scalable, high-performance applications that can run in the background. Check previous posts to delve into React-Native or into AI. Keep yourself posted and remember, just give it a try!