Until two years ago, I had exclusively done Android native development. I had never developed iOS apps, but that changed last year, when my company decided that I had to learn iOS development. I was super excited at first, but all that excitement started to fade away as I started developing our iOS app and I quickly saw how my productivity was declining. I realized I had to basically re-learn everything I learnt in Android: the framework, the tools, the IDE, etc. I am a person who likes going to meetups, so suddenly I started going to both Android and iOS meetups. I needed to keep up-to-date with the latest features in both platforms. It was very time-consuming and at the same time somewhat frustrating since I was feeling my learning pace was not fast enough. Then, React Native for iOS came out. We didn’t start using it until mid 2015. We started playing around with it and we really liked it.
What is React Native?
One reason why mobile development is so difficult and time consuming is the fact that two entirely different ecosystems need to be learned. If you want to develop an iOS app, then you need to learn Swift or Objective-C and Cocoa Touch. If you want to develop Android apps, you need to learn Java and the Android SDK. I have written code in the three languages, Swift, Objective C, and Java. I don’t really want to get into the argument of comparing which of these is better. However, what I can say is that they are different and learning each of them takes a considerable amount of time. A similar thing happens with the frameworks: Cocoa Touch and the Android SDK. Of course, with each of these frameworks, there is also a big bag of other tools such as testing tools, libraries, packages, etc. And we are not even considering that developers need to stay up-to-date with the latest features each ecosystem offers.
Reusability is a big thing in software development. Whenever you are able to reuse code that is a good thing.
React Native is not meant to be a write once, run everywhere platform. Whenever you want to build an app for them, you have to build a UI that looks and feels native. For this reason, some of the UI code needs to be written according to the platform's best practices and standards. However, there will always be some common UI code that can be shared together with all the logic. Being able to share code has many advantages: better use of human resources, less code to maintain, less chance of bugs, features in both platforms are more likely to be on parity, etc.
Learn Once, Write Everywhere
As I mentioned before, React Native is not meant to be a write once, run everywhere platform. As the Facebook team that created React Native says, the goal is to be a learn once, write everywhere platform. And this totally makes sense. Since all of the code for Android and iOS is written using the same set of tools, it is very easy to imagine having a team of developers building the app for both platforms. This is not something that will usually happen when doing native Android and iOS development because there are very few developers that do both. I can even go farther and say that a team that is developing a web app using React.js will not have a very hard time learning React Native development and start developing mobile apps.
When you build applications using React Native, your UI is more predictable and easier to understand since it has a declarative API as opposed to an imperative one. The difference between these approaches is that when you have an application that has different states, you usually need to keep track of all the changes in the UI and modify them. This can become a complex and very unpredictable task as your application grows. This is called imperative programming. If you use React Native, which has declarative APIs, you just need to worry about what the current UI state looks like without having to keep track of the older ones.
The usual developer routine when coding is to test changes every time some code has been written. For this to happen, the application needs to be compiled and then installed in either a simulator or a real device. In case of React Native, you don’t, most of the time, need to recompile the app every time you make a change. You just need to refresh the app in the simulator, emulator, or device and that’s it. There is even a feature called Live Reload that will refresh the app automatically every time it detects a change in the code. Isn’t that cool?
React Native is still a very new technology; it was made open source less than a year ago. It is not perfect yet. It still has some bugs, but, overall, I think it is ready to be used in production for most mobile apps. There are still some features that are available in the native frameworks that have not been exposed to React Native but that is not really a big deal. I can tell from experience that it is somewhat easy to do in case you are familiar with native development. Also, since React Native is open source, there is a big community of developers helping to implement more features, fix bugs, and help people. Most of the time, if you are trying to build something that is common in mobile apps, it is very likely that it has already been built.
As you can see, I am really bullish on React Native. I miss native Android and iOS development, but I really feel excited to be using React Native these days. I really think React Native is a game-changer in mobile development and I cannot wait until it becomes the to-go platform for mobile development!