Use react native to create a iOS framework and Android library (not app) from common code base

Question

Has anyone had any success using react native to create both iOS and Android apps that can be used as libraries/sub-projects in other iOS and Android native projects that were created without react native? My goal is to create new functionality for an existing app that has both a iOS and Android codebase that was developed without react native.

As a simple example, lets image that I need to create a series of screens and logic to allow a user to 'create a new account'. Ideally I would like to create the new functionality (controller, views, api-client, etc.) using react native and then export it as a self contained iOS and Android app. In addition to being able to run these apps on their own, I would also like to be able to include them in other native iOS/Android projects as sub-projects. The native iOS project would then create a new storyboard/ViewController/segue(s) and link the main-view of the react native iOS App to it.

I know on iOS/xcode I can add a sub-project by drag-and-dropping an .xcodepro into another one. If I did this with a .xcodepro that was created with react native, how would I go about linking the top level view to the existing non-react native iOS project? Is there a similar process on the Android side to achieve the same functionality?

Answer 1

I would like to explore React Native as well. We have similar needs as you - to develop a common library/framework for iOS and Android. Our solution was to code the library in C++ and use it in XCode on iOS and through a JNI (Java Native Interface) converter on Android as well. The JNI is a pain as not everything translates 1 to 1. I researched using Ruby/RubyMotion but that also has a JNI conversion step. There are other languages that do not require a JNI conversion - but from my last read these are also eperimental. Trying all of these will require effort and results are not guaranteed. Assuming aside from the shared library you still want Native for the rest of the App (UI etc), this will require developers with a combination of Swift, React, and Java (which could get expensive) The approach that makes most sense would be to use Swift for the iOS framework and Kotlin for the Android library and use the same style (functional/react-swift/react-java style code) That way, while the libraries are still different, they are coded in the same style so development/maintenance effort on one can be quickly copied/applied to the other.