Sebastian MarkbågeandGitHub
8a66937c88
Stacked on #31975. View Transitions cannot handle interruptions in that if you start a new one before the previous one has finished, it just stops and then restarts. It doesn't seamlessly transition into the new transition. This is generally considered a bad thing but I actually think it's quite good for fire-and-forget animations (gestures is another story). There are too many examples of bad animations in fast interactions because the scenario wasn't predicted. Like overlapping toasts or stacked layers that look bad. The only case interrupts tend to work well is when you do a strict reversal of an animation like returning to the page you just left or exiting a modal just being opened. However, we're limited by the platform even in that regard. I think one reason interruptions have traditionally been seen as good is because it's hard if you have a synchronous framework to not interrupt since your application state has already moved on. We don't have that limitation since we can suspend commits. We can do all the work to prepare for the next commit by rendering while the animation is going but then delay the commit until the previous one finishes. Another technical limitation earlier animation libraries suffered from is only have the option to either interrupt or sequence animations since it's modeling just one change set. Like showing one toast at a time. That's bad. We don't have that limitation because we can interrupt a previously suspended commit and start working on a new one instead. That's what we do for suspended transitions in general. The net effect is that we batch the commits. Therefore if you get multiple toasts flying in fast, they can animate as a batch in together all at once instead of overlapping slightly or being staggered. Interruptions (often) bad. Staggered animations bad. Batched animations good. This PR stashes the currently active View Transition with an expando on the container that's animating (currently always document). This is similar to what we do with event handlers etc. We reason we do this with an expando is that if you have multiple Reacts on the same page they need to wait for each other. However, one of those might also be the SSR runtime. So this lets us wait for the SSR runtime's animations to finish before starting client ones. This could really be a more generic name since this should ideally be shared across frameworks. It's kind of strange that this property doesn't already exist in the DOM given that there can only be one. It would be useful to be able to coordinate this across libraries.
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 the 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 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 Quick Start to get a taste of React.
- Add React to an Existing Project to use as little or as much React as you need.
- Create a New React App if you're looking for a powerful JavaScript toolchain.
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:
- Quick Start
- Tutorial
- Thinking in React
- Installation
- Describing the UI
- Adding Interactivity
- Managing State
- Advanced Guides
- API Reference
- Where to Get Support
- Contributing Guide
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:
import { createRoot } from 'react-dom/client';
function HelloMessage({ name }) {
return <div>Hello {name}</div>;
}
const root = createRoot(document.getElementById('container'));
root.render(<HelloMessage name="Taylor" />);
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.
Contributing
The main purpose of this repository is to continue evolving 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 that have a relatively limited scope. This is a great place to get started.
License
React is MIT licensed.