Let's Get Clear About React Native

If you ever came to a conversation about mobile apps development then, of course, you have been chatting about React Native or at least you have heard about it. Maybe you know a little about it and how it works but you don’t know all the truth. But at Simply we do and now we will tell you about all the superpowers of this unique JavaScript technology.

Before uncovering all the truth about this technology first you need to have an idea where its name comes from and what it actually means. React Native = React (a JavaScript library) + Native (mobile application type). Let’s dive deeper and find out what this equation means.

So, what is React?


React is a JavaScript library open-sourced back in 2013 by Facebook. It helps to build user interfaces for single page web applications. Unlike larger MVC-style JavaScript frameworks (Angular, Ember, Backbone, etc), React has a relatively narrow scope of applications. It only renders your applications’ user interface.

React is the 5th most starred repository on Github, and this means it is loved by a huge number of JavaScript developers worldwide. Why? Because it is lightweight and offers amazing performance, particularly when it comes to quickly changing data. Also, its component structure allows you to write more modular and reusable code thus saving time and other resources.

And what is a native app?


A native mobile app is an application that is developed for smart devices such as smartphones, tablets, and gadgets coded in a specific programming language: Objective C/Swift for iOS and Java/Kotlin for Android operating systems. Native mobile apps are high performing and reliable. They have access to the device’s APIs and features. Also, they let users use some apps without an internet connection. But developing this type of applications usually requires more financial, human and time resources just because two separate codebases are developed for two different platforms in two different languages by two different teams of developers.

What Is React Native? is it React running on mobile?


If not to go deep, then yes! In a developer’s perspective, React Native is just React running on mobile with a few differences in components and tags uses. This is why this trending technology feels entirely familiar and comfortable to React developers. As the mobile development needs its own tricky considerations then some Objective-C/Swift or Java knowledge also can be useful while developing in React Native.

What is React Native in real? This unique JavaScript technology makes possible to develop a cross-platform mobile application that looks and feels like a native one but it is coded by a single team of engineers simply using React and JavaScript. But when we say it feels almost native, then what are the differences between React Native and Native applications? Let’s go deep and find them out.

React Native and Native apps differences

One of the first things that people always hear about React Native is that it's "actually" native. Okay, but how much? Here are some basic differences that you can find between these two different apps developed in a native language and React Native.

#Developing a native app for iOS/Android

Twitter mobile apps are fully native.

Twitter mobile apps are fully native.

Android and iOS are completely native platforms and they have some prerequisites that you need to know before starting your mobile app development. First of all, to develop native applications for this two platforms you need to code your applications in two different languages.

To build a native mobile application for the iOS operating system that has great performance and easy access to device APIs and functionalities, the knowledge of Objective-C/Swift is required. While if you are developing a native mobile app for Android, Java/Kotlin are the languages to be used. In terms of tooling, you’ll require employing an individual platform’s integrated development environment (IDE) as well as take in how that IDE and the relevant debugger can help you build the system. Native applications are more efficient in terms of central processing unit usage. And as they use more memory on average they make easier to manage the memory when the app grows.

Apple and Google provide mobile developers with their own development tools, interface elements, and standardized SDK; Xcode and Android Studio thus easing the development process. Pokemon Go, Twitter, and Waze are fully native applications that were developed in strict programming languages - that is in native ones.

Overall, native apps always outperform any other apps but they require more time, more people, more financial resources that’s why developers opt for React Native that is indistinguishably as native as the real native apps.

#Developing a cross-platform React Native app

Adidas GLITCH app is written in React Native

Adidas GLITCH app is written in React Native

Building a cross-platform app means to write one codebase that can run on different native platforms. React Native allows not only to develop a cross-platform app but also an app that feels like native and performs nearly as well as the real ones. It makes possible to write two different applications just using one language. React Native saves time, shortens the development process, and being a JavaScript framework, it makes the transition from web to mobile development smoother.

Since React Native doesn’t support all APIs, to access some APIs and functionalities you need to use native modules which are that part of the code that is written in a native language and is incorporated into the rest of the script. For a React Native application development, you need to use native modules also for using third-party libraries and for accessing other native applications. But as the technology is open-sourced that gives the opportunity to get constant improvements, new features and bug fixes by other community members.

React Native is not Ionic

Ionic is a hybrid application development framework. Hybrid apps are essentially websites that are embedded in a mobile app with the help of webview. Frameworks like Ionic use web technologies to write and render the application, and require tools like PhoneGap/Cordova to access native features of the device, like GPS or camera. They create mobile applications using HTML5, CSS, and Javascript, and execute the same code no matter on what platform they run. 

As native apps are developed in the language required by the platform it targets, the code gives direct access to all features offered by the platform without any restriction.

And React Native app is to some extent, the mix of hybrid and native apps - it uses JavaScript and React and feels native. Developers goal is to develop a fast and responsive app, with React Native is the golden mean of all the technologies that exist in mobile development.

How React Native works


In the case of React, the Virtual DOM is like a layer between the developer’s description of how things must look, and the work that is already done to render the application onto the page. To render interactive UIs in a browser, developers must make changes to the browser’s DOM. While in React Native, instead of rendering to the browser’s DOM, React Native uses native APIs to render to platform-specific components: it invokes Objective-C/Swift or Java APIs to render to iOS and Android components. This is a distinctive feature of React Native that sets it apart from other cross-platform mobile application development technologies which often end up rendering web-based views. 

To understand how React Native works under the hood, you can check out this blog post by Shahen Hovhannisyan, a senior software engineer at Simply. 

React native pros and cons

#pros of React Native

Multi-platform Development

React Native enables using the same code base or a part of it between the iOS and Android operating systems. Practically, full cross-platform development is possible to some extent, of course, depending how many native modules you include in your script․ Though to develop an app for iOS you cannot use WindowsOS but with MacOS you will be able to write multi-platform mobile application without any issues.

Shorter Development Time

One of the strongest sides of React Native is its faster development. Its numerous ready-to-apply components accelerate the development process and due to its ability to share a big part of a code base between operating systems in short time-frame, you potentially halve the development time if you developed two separate native apps for iOS and Android.

Live and Hot Reloading

Thanks to hot reloading, a developer can keep the app running while implementing new versions and tweaking the UI. It makes changes in the app instantly visible without the need for the developer to save them. This boosts productivity and saves a lot of time. The idea behind hot reloading is to keep the app running and to inject new versions of the files that you edited at the run-time. This way, you don't lose any of your state which is especially useful if you are tweaking the UI. 

One team development

Native development requires two independent teams of Android and iOS developers. While developing in React Native, you will mostly need JavaScript developer who can write the code for both platforms. Obviously, to build mobile applications that need more native features, native developers' help also will be required. But overall, React Native development teams are small and easily manageable.

Native Performance

Though JavaScript can not be as fast as native code, in most cases, you won’t see the difference is really slight and unnoticeable to an average user. While developing more complex applications, the technology might appear less effective, but native codes are always there to help you out, so it is no longer a problem.

Simplified UI

React Native is solidly based on creating a mobile UI. In native development, it is necessary to create a sequence of actions in the application, whereas React Native allows to see everything in the script. As a result, it is much easier to see the path a user can take and also to detect bugs on their way.

#cons of React Native

Still Less Native Navigation

React Native still lacks navigation components to provide users with seamless UX. There is no ideal solution in the technology for navigation between displays but it is getting better and better day by day. Our team made some open-source contributions with some navigation pull requests on GitHub. And one of JavaScript engineers share some React Native optimization tips in another blog-post here.

Few Custom Modules

Despite its daily improvements, React Native still lacks some components. And there are still some components that are partially developed. The chances are you won’t have a problem with that, as the majority of custom modules you need are available, well-documented and working properly.

Still requires native code

To implementing some native features and modules in React Native script requires detailed knowledge of a particular platform. React Native does offer custom modules that you can refactor across operating systems, but in case of the access to device sensors, camera or push-notifications you need also some help from iOS and Android developers. Their input depends on the complexity of your project, but you need to bargain for them when kicking off with React Native.

famous companies using React native

A Part of the Facebook app is developed in React Native

A Part of the Facebook app is developed in React Native

With its growing fame, a number of great and well-known applications are being developed and seen in the app stores built with this technology. React Native is the most preferred choice in the mobile app development industry, no matter it is a startup or a Fortune 500 company. So, in another blog post we have put together 8 amazing and popular mobile apps that were developed with React Native to understand the reasons that make the industry leaders like Facebook, AirBnB, Tesla, etc. choose this technology.

React Native is truly rocking the mobile development industry because it is easy and fast to develop and performs really well. But in fact the choice of your technology depends on your project and its functionalities. In all cases, anyway, React Native is an efficient and economy variant that enables multi-functional and multi-platform mobile app development. 

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