Nick Gerleman
69f761f1ac
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/48718 This diff looks a bit scary, but it's mostly just structural changes of existing code and some deletion, on a well tested path 😅. The current parser implementation tries to special case "basic" data types. When I was looking at how to add in support for more complex values, such as lists, function notations, and more compounded types, this distinction ends up not making much sense. Instead of treating some types as basic, this diff instead moves to a model where a user can declare any structure as a `CSSDataType`, so long as they also supply a parser, which may be visited when iterating through CSS syntax blocks (preserved tokens, function blocks, or simple blocks, which probably won't be used). The user then specifies a list of supported CSS data types to parse, which invokes said parser, calling any defined methods for specific syntax. E.g. ```cpp struct CSSNumber { float value{}; }; template <> struct CSSDataTypeParser<CSSNumber> { static constexpr auto consumePreservedToken(const CSSPreservedToken& token) -> std::optional<CSSNumber> { if (token.type() == CSSTokenType::Number) { return CSSNumber{token.numericValue()}; } return {}; } // Could also accept function block here as well (e.g. for future math // expressions) }; static_assert(CSSDataType<CSSNumber>); ``` ```cpp // Can be one of std::monostate (variant null-type), CSSWideKeyword, // CSSNumber, CSSLength, or CSSPercentage. In this case, a CSSLength. auto value = parseCSSProperty<CSSNumber, CSSLength, CSSPercentage>("5px"); ``` This breaks a whole lot of assumptions I made a year ago, especially around `CSSValueVariant` which must now be able to handle arbitrary values. For now, for the sake of simplicity, I threw this out, and migrated parser code to use plain-old `std::variant`, which has a downside of being a bit less optimized in terms of storage. I also ended up completely throwing out `CSSDeclaredStyle`, since it would majorly need to change, and we're not going to be migrating style storage quite yet. This change also broke the `CSSProperties.h` property definitions and parsing shorthand a bit, which we will need for value processing later. I also opted to delete this for now (a big centralized list is the wrong structure anyways), but will likely copy bits from its source history later. Another particular hairy bit, that likely won't bite us in practice, is that some strings may be parseable under different data types. This just adds caller requirement to order the types correctly, instead of precedence being implemented as part of the parser. Changelog: [Internal] Reviewed By: lenaic Differential Revision: D68245734 fbshipit-source-id: 132b11053cf41f57483c89176a9a6dceebb69fad
React Native
Learn once, write anywhere:
Build mobile apps with React.
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React Native brings React's declarative UI framework to iOS and Android. With React Native, you use native UI controls and have full access to the native platform.
- Declarative. React makes it painless to create interactive UIs. Declarative views make your code more predictable and easier to debug.
- Component-Based. Build encapsulated components that manage their state, then compose them to make complex UIs.
- Developer Velocity. See local changes in seconds. Changes to JavaScript code can be live reloaded without rebuilding the native app.
- Portability. Reuse code across iOS, Android, and other platforms.
React Native is developed and supported by many companies and individual core contributors. Find out more in our ecosystem overview.
Contents
- Requirements
- Building your first React Native app
- Documentation
- Upgrading
- How to Contribute
- Code of Conduct
- License
📋 Requirements
React Native apps may target iOS 15.1 and Android 7.0 (API 24) or newer. You may use Windows, macOS, or Linux as your development operating system, though building and running iOS apps is limited to macOS. Tools like Expo can be used to work 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:
📖 Documentation
The full documentation for React Native can be found on our website.
The React Native documentation discusses components, APIs, and topics that are specific to React Native. For further documentation on the React API that is shared between React Native and React DOM, refer to the React documentation.
The source for the React Native documentation and website is hosted on a separate repository, @facebook/react-native-website.
🚀 Upgrading
Upgrading to new versions of React Native may give you access to more APIs, views, developer tools, and other goodies. See the Upgrading Guide for instructions.
React Native releases are discussed in this discussion repo.
👏 How to Contribute
The main purpose of this repository is to continue evolving React Native core. We want to make contributing to this project as easy and transparent as possible, and we are grateful to the community for contributing bug fixes and improvements. Read below to learn how you can take part in improving React Native.
Code of Conduct
Facebook has adopted a Code of Conduct that we expect project participants to adhere to. Please read the full text so that you can understand what actions will and will not be tolerated.
Contributing Guide
Read our Contributing Guide to learn about our development process, how to propose bugfixes and improvements, and how to build and test your changes to React Native.
Open Source Roadmap
You can learn more about our vision for React Native in the Roadmap.
Good First Issues
We have a list of good first issues that contain bugs which have a relatively limited scope. This is a great place to get started, gain experience, and get familiar with our contribution process.
Discussions
Larger discussions and proposals are discussed in @react-native-community/discussions-and-proposals.
📄 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.