e81adb99f3
Summary:
The reasoning behind this change is that right now, having both added and modified modules inside of a single `modules` field doesn't allow for basic operations like combining two deltas.
For instance, say I have three different bundle revisions: A, B and C.
Module 42 was added in B, and then removed in C.
A->B = `{modules: [42, "..."], deleted: []}`
B->C = `{modules: [], deleted: [42]}`
A->C = `{modules: [], deleted: []}`
However, were we to compute A->C as the combination of A->B and B->C, it would result in `{modules: [], deleted: [42]}` because we have no way of knowing that module 42 was only just added in B.
This means that the `deleted` field of delta X->Y might eventually contain module ids that were never present in revision X, because they were added and then removed between revisions X and Y.
The last time I changed the delta format, we had a few bug reports pop out from people who had desync issues between their version of React Native and their version of Metro. As such, I've tried to make this change backwards compatible in at least one direction (new RN, old Metro). However, this will still break if someone is using a newer version of Metro and an older version of RN. I created T37123645 to follow up on this.
Reviewed By: rafeca, fromcelticpark
Differential Revision: D13156514
fbshipit-source-id: 4a4ee3b6cc0cdff5dca7368a46d7bf663769e281
React Native · 
Learn once, write anywhere: Build mobile apps with React.
See the official React Native website for an introduction to React Native.
Requirements
Supported target operating systems are >= Android 4.1 (API 16) and >= iOS 9.0. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS by default (tools like Expo can be used to get around this).
Building your first React Native app
Follow the Getting Started guide. The recommended way to install React Native depends on your project. Here you can find short guides for the most common scenarios:
How React Native works
React Native lets you build mobile apps using JavaScript. It uses the same design as React, letting you compose a rich mobile UI from declarative components.
With React Native, you don't build a "mobile web app", an "HTML5 app", or a "hybrid app". You build a real mobile app that's indistinguishable from an app built using Objective-C, Java, Kotlin, or Swift. React Native uses the same fundamental UI building blocks as regular iOS and Android apps. You just put those building blocks together using JavaScript and React.
React Native lets you build your app faster. Instead of recompiling, you can reload your app instantly. With hot reloading, you can even run new code while retaining your application state.
React Native combines smoothly with components written in Objective-C, Java, Kotlin, or Swift. It's simple to drop down to native code if you need to optimize a few aspects of your application. It's also easy to build part of your app in React Native, and part of your app using native code directly - that's how the Facebook app works.
The focus of React Native is on developer efficiency across all the platforms you care about - learn once, write anywhere. Facebook uses React Native in multiple production apps and will continue investing in React Native.
Full documentation
The full documentation for React Native can be found on our website. The source for the React Native documentation and website is hosted on a separate repo, https://github.com/facebook/react-native-website.
The React Native documentation only discusses the components, APIs, and topics specific to React Native (React on iOS and Android). For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
Join the React Native community
- Website: https://facebook.github.io/react-native
- Twitter: https://twitter.com/reactnative
- Discussion: https://discuss.reactjs.org/
See the CONTRIBUTING file for how to help out.
License
React Native is MIT licensed, as found in the LICENSE file.
React Native documentation is Creative Commons licensed, as found in the LICENSE-docs file.