How Does React Native Work?
Tags: javascript, reactnative, beginners, opensource
Published: 2021-10-06 11:49:21

React Native is one of the leading cross-platform developing frameworks nowadays. [Recent research shows] (https://www.statista.com/statistics/869224/worldwide-software-developer-working-hours/) that 38% of developers use React Native to create mobile, desktop, and other types of apps in 2021.

React Native is valuable because of the open-source, broad spectrum of features and application area it presents. In this article, we invite you to look under the hood of the framework and find out:

- What is React Native;
- How does React Native work?;
- React Native development process;
- React Native features;
- The future of React Native.

## What is React Native

React Native was created in 2015 by Facebook. Developers wrote it in JavaScript after they faced the problem of rendering React web applications on mobile devices. It gained popularity very fast for its features and capabilities. Among the React Native applications are Instagram, Facebook, Tesla, Skype, UberEats, Walmart, and Shopify.

Initially, the Facebook team designed React Native to create natively rendering Android, and iOS mobile apps, using React JS library. Then, due to the open environment of the framework, developers from all over the world contributed to it and extended its capabilities. Now, [it works with major mobile platforms] (https://reactnative.dev/docs/out-of-tree-platforms) and Linux, macOS, Windows, etc. 

## How does React Native work?

### React Native architecture

The cross-platform capability of React Native becomes possible owing to its unique architecture. 

The core element of React Native architecture is the Bridge. This system employs React library to render the application on a device. Simply put, the bridge transforms the JS code into the native components and vice versa. The bridge translates JavaScript into platform-specific components. It gets the JS call, leverages the APIs (Kotlin, Objective C, Java), which allows native rendering of an application. The process doesn’t affect user experience because these async calls take place apart from the main thread.

However, if your app employs multiple threads and large amounts of data, this structure can cause delays. 

### Development process

React Native is based on React and uses the single JavaScript codebase to reuse the code on various platforms. Unlike Ionic and many other cross-platform development frameworks, React Native renders native components by invoking platform-specific APIs. For instance, to render UI components on iOS, React Native uses either Objective C or Swift APIs. As for Android mobile applications, it will be Java or Kotlin. In fact, a developer doesn’t need to know Objective C or Java to create the apps. 

The React Native development process happens in JavaScript, TypeScript, and JSX. The developers can reuse significant parts (up to 100%) of the code. 

Another peculiarity of React Native is its commands for component creation. Instead of HTML components, RN has specific components that replace them.

Also, features like 3d party library support, hot reload, and vast UI libraries make the development process much more easy and productive for developers. When an application is ready, you can connect it with [a cloud or local database] (https://www.akveo.com/blog/7-best-react-native-databases-and-how-to-choose-the-right-one-in-2021) to provide the storage capacity.

## React Native features

Here, we will elaborate on React Native features that make the framework prominent.

### NPM repository support

NPM (Node Package Manager) streamlines React Native apps development process. NPM is a repository of pre-made libraries that developers can use working with React Native framework. This feature makes the development process much faster, allowing React Native developers to upload the code patterns from the NPM libraries. 

### Code reusability

This is the core feature of any cross-platform development framework. However, the percentage of code you can reuse varies from platform to platform. In the case of React Native, you can use almost all the code throughout the different platforms. This feature saves plenty of time and reduces costs.

### Flexible programming language

The programming language and its flexibility play a crucial part in the framework’s performance and success. The more common the core language of the cross-platform development framework, the faster and easier the learning process becomes. It means you won’t have any problems training your JS developers to work with React Native. However, if you want to create a unique app faster, it makes sense [to hire experienced React Native developers] (https://www.akveo.com/blog/how-to-hire-a-dedicated-react-native-developer-in-2021-ultimate-guide-interview-questions).

Apart from that, React Native uses JavaScript as a base and supports TypeScript out-of-the-box. These peculiarities make the React Native platform accessible for a larger group of developers. [According to the latest developer survey] (https://insights.stackoverflow.com/survey/2020#technology-programming-scripting-and-markup-languages-professional-developers), JS is the most popular programming language, with around 70% of developers using it.

### Strong developer community

React Native framework became popular among developers around the world almost instantly after its launch in 2015. Ever since, the community has been growing and contributing to the open-source framework, extending its functionality and making it faster. This characteristic secures the future of React Native cross-platform framework and makes it attractive for other developers.

### 3d party libraries support

Another feature that makes React Native stand out from the other cross-platform frameworks is the 3d party libraries’ support. Integration with 3d party libraries empowers developers with more out-of-the-box solutions and broadens the development opportunities. 

### High performance in mobile environments

[React Native has been working with mobile platforms] (https://www.akveo.com/blog/react-native-for-mobile-app-development-points-to-consider-in-2021) (iOS, Android) from the first day of its existence. No wonder it has excellent performance with mobile apps development. React Native developers can reuse more code in the mobile environment than in any other, making it the fastest cross-platform framework for mobile apps now. 

### Live & Hot reload

The HMR (Hot Module Replacement) facility allows React Native developers to change, add, and modify modules while the system is on the go. As a result, this feature streamlines the app development process in the following ways:

- Saves time by updating only the changed code;
- Retains application’s state (that’s lost during the full reload);
- Updates the browser as soon as modifications in the JS code are made.

The live reload feature of React Native allows you to see the changes on your screen as soon as you change them. This feature is especially useful for mobile apps development. 

### Rich UI capabilities 

React Native framework is the go-to option if you give much attention to the UI of your application. The framework has exceptional rendering capabilities along with numerous UI libraries for all types of applications.

## The future of React Native

The Facebook team, along with all the contributors from the developer community, continue upgrading the React Native environment. They add new features, widen the functionality of React Native, and expand its cross-platform capacity. 

There is no doubt that with the high performance and the dedicated developer community behind it, React Native is here to stay and will continue to emerge. Currently, React Native framework emerges in the following directions:

### Streaming model upgrade

Currently, React Native community is bringing to life the Fabric project that should change the existing mechanism once and for all. It will allow developers to invoke JavaScript synchronously on a given thread. This feature will reduce the main thread load time without hindering the response.

### Moving towards platform-agnosticism

Platform-agnosticism is a certain app development philosophy that aims to create totally cross-platform applications. According to the concept, the ideal app is the one you can create once and use on every platform without any additional code manipulations. Although it’s not easy to achieve, the React Native community strives to make the framework capable of creating perfectly cross-platform applications.

### Bridge simplification

The next development direction React Native community is moving towards is bridge simplification. This will enhance direct invocation between native and JavaScript and allow the creation of new debugging tools.

### Extension of Async capabilities

Async upgrade is aiming to enhance the asynchronous rendering of React Native framework. This, in its turn, will streamline asynchronous data handling and rendering.

## Conclusion

Taking into account all the technologies and features React Native represents, we can say for sure that it is a top cross-platform development framework. Developer community recognition, thousands of outstanding applications with billiards of users prove it. With the support of Facebook and thousands of contributors, React Native will definitely evolve and make the app development process easier, faster, and more enjoyable.

By the way, the Akveo developers’ team is proud to add value to the React Native community with the free and open-source UI Kitten based on the [Eva Design system] (https://eva.design/products). Many developers saved their time, and money, using it. You can [try the Kitten and see all the benefits for yourself] (https://akveo.github.io/react-native-ui-kitten/).