What Backward Compatibility Is
This documentation is still experimental and details are subject to changes as we iterate. Feel free to share your feedback on the discussion inside the working group for this page.
Moreover, it contains several manual steps. Please note that this won't be representative of the final developer experience once the New Architecture is stable. We're working on tools, templates and libraries to help you get started fast on the New Architecture, without having to go through the whole setup.
Creating a backward compatible module is important to provide a library that works in both the Old Architecture and the New Architecture. Not all the users of your library will immediately jump on the New Architecture ship: it is a good thing that they will be able to use your library even if they are still using the old architecture.
The trick to create a good backward compatible module is to minimize the changes required to adopt the new version. In that way, users of the module can smoothly move to the new version and migrate to the New Architecture when they are ready, ideally by issuing one different command.
To achieve this result, we have to perform few changes in our Turbo Native Module and Fabric Native Component configurations. The steps we have to follow are:
- Update the installation configuration to avoid using code that is not needed by the Old Architecture.
- Update the code to support both architectures. Both Android and iOS build pipelines gives you mechanism to provide a library that will compile with the correct React Native Architecture.
- Configure the specs to load the proper implementation, so that the JavaScript layer leverages the New Architecture when it is available.
The next sections requires that you are familiar with the Pillars of the New Architecture.
- To create a backward compatible Turbo Native Module, follow this guide.
- To create a backward compatible Fabric Native Component, follow this guide.