f671f8868f
Summary: This is a bandaid fix to address a crash with a stack trace involving ``` com.facebook.react.uimanager.IllegalViewOperationException: Trying to add a root view with an explicit id already set. React Native uses the id field to track react tags and will overwrite this field. If that is fine, explicitly overwrite the id field to View.NO_ID before calling addRootView. 0+com.facebook.react.uimanager.NativeViewHierarchyManager.addRootViewGroup(NativeViewHierarchyManager.java:546) [inlined] 1+com.facebook.react.uimanager.NativeViewHierarchyManager.addRootView(NativeViewHierarchyManager.java:538) [inlined] 2+com.facebook.react.uimanager.UIViewOperationQueue.addRootView(UIViewOperationQueue.java:678) [inlined] 3+com.facebook.react.uimanager.UIImplementation.registerRootView(UIImplementation.java:216) [inlined] 4+com.facebook.react.uimanager.UIManagerModule.addRootView(UIManagerModule.java:355) 5+com.facebook.react.ReactInstanceManager.attachRootViewToInstance(ReactInstanceManager.java:1032) 6+com.facebook.react.ReactInstanceManager.attachRootView(ReactInstanceManager.java:726) [inlined] 7+com.facebook.react.ReactRootView.attachToReactInstanceManager(ReactRootView.java:524) 8+com.facebook.react.ReactRootView.startReactApplication(ReactRootView.java:377) ``` This crash seems to be happening because the root view's id is set to a non NO_ID value, but further up in the stack trace, UIManager.addRootView() is called which always sets the root view's id to NO_ID. It's not clear how this error is happening, but in this code path it's expected that addRootView should always ensure that the id is always reset. In order to avoid crashing for this, let's remove the exception and log the issue instead. In the future, we should not be overloading the android view id field with these types of react native implementation details. The react tag should be stored as a view tag instead. Reviewed By: mmmulani Differential Revision: D10499861 fbshipit-source-id: 4dffedab4e7a34eee7f64bb43ec8209699521c73
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.