Moti Zilberman
97723efc8d
Summary: Pull Request resolved: https://github.com/facebook/react-native/pull/42746 Changelog: [Internal] Formally introduces the concept of "session state" to the modern CDP backend, with the simplest possible implementation: * `PageTargetSession` has a mutable `SessionState` member. * All agents receive the same `SessionState&` in their constructor (with `SessionState`'s lifetime being the caller's responsibility). * It's only legal to read/write to `SessionState` on the thread where requests are handled and Agents are created (the "main" thread). * Agents are expected to play nice and not clobber each other's state in `SessionState`; this is *not* protected with visibility or `const`ness, however. * We'll probably want to come up with some API-level mechanism to control this as the complexity of our agents grows. ## Current use case: `<Domain>.enable` The first use case for session state is to let `PageAgent` manage the `Log.enable` and `Runtime.enable` state for the session. This will allow agents created later in the session (or recreated as part of a reload) to emit Log and Runtime notifications without waiting for additional `enable` messages (that the client is not required to send). We'll likely want to generalise this design to arbitrary domains in some way (e.g. add a top-level domain router that agents register with explicitly?) but I went with the simplest implementation for our current needs. NOTE: The CDP spec doesn't state this explicitly, but it's clear from Chrome's behaviour that a `<Domain>.enable` command is intended to be session-scoped and survive reloads. ## Future use case: Instance/Runtime state persistence The `<Domain>.enable` use case could have been solved with passing *immutable* state to Agents (`const SessionState&`). We make the state mutable in anticipation of `HermesRuntimeAgent` needing to store its own state in the session down the line, which we know is going to be needed in order for breakpoints to survive reloads. Agents that never need to mutate state SHOULD only store this as a const reference. Reviewed By: huntie Differential Revision: D53006916 fbshipit-source-id: a0443c507294faa94efdf25b2f1670129774dc78
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 13.4 and Android 6.0 (API 23) 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 repo, @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.