f77aa4eb45
Summary: iOS-specific. For languages with complex input (such as Japanese or Chinese), a user has to type multiple characters that are then merged into a single one. If `-[UITextView setAttributedString:]` is used while the user is still typing, it resets the input and characters are not being treated as typed together. This PR avoids calling this method if possible, replacing it by just copying the attributes if the string has not been changed. That preserves the state and user can continue to type Korean or Chinese characters. Fixes #19339 <!-- Required: Write your motivation here. If this PR fixes an issue, type "Fixes #issueNumber" to automatically close the issue when the PR is merged. --> <!-- Required: Write your test plan here. If you changed any code, please provide us with clear instructions on how you verified your changes work. Bonus points for screenshots and videos! --> Essentially, the steps to reproduce are described in [the issue](https://github.com/facebook/react-native/issues/19339): 1. Type some Korean characters in TextInput, such as "하늘" (buttons `ㅎ`,`ㅏ`,`ㄴ`,`ㅡ`,`ㄹ`). 2. Then move the cursor to the beginning of the text, type "파란" (buttons `ㅍ`,`ㅏ`,`ㄹ`,`ㅏ`,`ㄴ`) this time. **Behaviour before this fix (broken)** Actual text: `ㅍㅏㄹㅏㄴ하늘`. Expected text: `파란하늘`. Characters aren't combined properly.  **Behaviour after this fix (correct)** Actual text: `파란하늘`. Expected text: `파란하늘`. Characters are combined, the same behaviour is in vanilla iOS `UITextView`.  <!-- Does this PR require a documentation change? Create a PR at https://github.com/facebook/react-native-website and add a link to it here. --> <!-- Required. Help reviewers and the release process by writing your own release notes. See below for an example. --> [IOS] [BUGFIX] [TextView] - Fix Korean/Chinese/Japanese input for multiline TextView on iOS. <!-- **INTERNAL and MINOR tagged notes will not be included in the next version's final release notes.** CATEGORY [----------] TYPE [ CLI ] [-------------] LOCATION [ DOCS ] [ BREAKING ] [-------------] [ GENERAL ] [ BUGFIX ] [ {Component} ] [ INTERNAL ] [ ENHANCEMENT ] [ {Filename} ] [ IOS ] [ FEATURE ] [ {Directory} ] |-----------| [ ANDROID ] [ MINOR ] [ {Framework} ] - | {Message} | [----------] [-------------] [-------------] |-----------| EXAMPLES: [IOS] [BREAKING] [FlatList] - Change a thing that breaks other things [ANDROID] [BUGFIX] [TextInput] - Did a thing to TextInput [CLI] [FEATURE] [local-cli/info/info.js] - CLI easier to do things with [DOCS] [BUGFIX] [GettingStarted.md] - Accidentally a thing/word [GENERAL] [ENHANCEMENT] [Yoga] - Added new yoga thing/position [INTERNAL] [FEATURE] [./scripts] - Added thing to script that nobody will see --> Pull Request resolved: https://github.com/facebook/react-native/pull/19809 Differential Revision: D13326614 Pulled By: shergin fbshipit-source-id: 6a5cab3f7290f0f623a6f4c29353a573eb321b0b
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
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- 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.