Andrew Clark
3af91eb8ce
* [scheduler] Internal rename: Callback -> Task Rename Callback type to Task. Does not affect the public API, only internal names, though eventually we'll probably want to align with the WICG Main-thread Scheduling proposal (https://github.com/WICG/main-thread-scheduling). * [scheduler] flushFirstTask() -> flushTask(task) Pass task as an argument to `flushTask` instead of using a module- level variable. * [scheduler] Add startTime field This does not change any semantics, but in the future `startTime` may represent a future time, to support delayed tasks. * [Scheduler] Use continuation pattern for host cb As I prepare to implement integrated timers, I noticed some peculiarities in the Scheduler implementation that could afford to be cleaned up. This is a refactor and shouldn't affect any observable behavior; mostly it removes some concepts that existed in earlier iterations of Scheduler and are no longer needed. The main change is to how the DOM implementation schedules an additional callback before yielding to the main thread. It used to follow the same code path for scheduling task; now it has its own branch directly inside the message event handler. The special case for error handling — where we call `postMessage` immediately without waiting for rAF — has similarly been localized inside the catch block of the message event handler.
React · 
React is a JavaScript library for building user interfaces.
- Declarative: React makes it painless to create interactive UIs. Design simple views for each state in your application, and React will efficiently update and render just the right components when your data changes. Declarative views make your code more predictable, simpler to understand, and easier to debug.
- Component-Based: Build encapsulated components that manage their own state, then compose them to make complex UIs. Since component logic is written in JavaScript instead of templates, you can easily pass rich data through your app and keep state out of the DOM.
- Learn Once, Write Anywhere: We don't make assumptions about the rest of your technology stack, so you can develop new features in React without rewriting existing code. React can also render on the server using Node and power mobile apps using React Native.
Learn how to use React in your own project.
Installation
React has been designed for gradual adoption from the start, and you can use as little or as much React as you need:
- Use Online Playgrounds to get a taste of React.
- Add React to a Website as a
<script>tag in one minute. - Create a New React App if you're looking for a powerful JavaScript toolchain.
You can use React as a <script> tag from a CDN, or as a react package on npm.
Documentation
You can find the React documentation on the website.
Check out the Getting Started page for a quick overview.
The documentation is divided into several sections:
You can improve it by sending pull requests to this repository.
Examples
We have several examples on the website. Here is the first one to get you started:
function HelloMessage({ name }) {
return <div>Hello {name}</div>;
}
ReactDOM.render(
<HelloMessage name="Taylor" />,
document.getElementById('container')
);
This example will render "Hello Taylor" into a container on the page.
You'll notice that we used an HTML-like syntax; we call it JSX. JSX is not required to use React, but it makes code more readable, and writing it feels like writing HTML. If you're using React as a <script> tag, read this section on integrating JSX; otherwise, the recommended JavaScript toolchains handle it automatically.
Contributing
The main purpose of this repository is to continue to evolve React core, making it faster and easier to use. Development of React happens in the open on GitHub, and we are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can take part in improving React.
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.
Good First Issues
To help you get your feet wet and get you familiar with our contribution process, 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.
License
React is MIT licensed.