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Jack Pope
6aa8254bb7
*This API is experimental and subject to change or removal.* This PR is an alternative to https://github.com/facebook/react/pull/32421 based on feedback: https://github.com/facebook/react/pull/32421#pullrequestreview-2625382015 . The difference here is that we traverse from the Fragment's fiber at operation time instead of keeping a set of children on the `FragmentInstance`. We still need to handle newly added or removed child nodes to apply event listeners and observers, so we treat those updates as effects. **Fragment Refs** This PR extends React's Fragment component to accept a `ref` prop. The Fragment's ref will attach to a custom host instance, which will provide an Element-like API for working with the Fragment's host parent and host children. Here I've implemented `addEventListener`, `removeEventListener`, and `focus` to get started but we'll be iterating on this by adding additional APIs in future PRs. This sets up the mechanism to attach refs and perform operations on children. The FragmentInstance is implemented in `react-dom` here but is planned for Fabric as well. The API works by targeting the first level of host children and proxying Element-like APIs to allow developers to manage groups of elements or elements that cannot be easily accessed such as from a third-party library or deep in a tree of Functional Component wrappers. ```javascript import {Fragment, useRef} from 'react'; const fragmentRef = useRef(null); <Fragment ref={fragmentRef}> <div id="A" /> <Wrapper> <div id="B"> <div id="C" /> </div> </Wrapper> <div id="D" /> </Fragment> ``` In this case, calling `fragmentRef.current.addEventListener()` would apply an event listener to `A`, `B`, and `D`. `C` is skipped because it is nested under the first level of Host Component. If another Host Component was appended as a sibling to `A`, `B`, or `D`, the event listener would be applied to that element as well and any other APIs would also affect the newly added child. This is an implementation of the basic feature as a starting point for feedback and further iteration.
react-dom
This package serves as the entry point to the DOM and server renderers for React. It is intended to be paired with the generic React package, which is shipped as react to npm.
Installation
npm install react react-dom
Usage
In the browser
import { createRoot } from 'react-dom/client';
function App() {
return <div>Hello World</div>;
}
const root = createRoot(document.getElementById('root'));
root.render(<App />);
On the server
import { renderToPipeableStream } from 'react-dom/server';
function App() {
return <div>Hello World</div>;
}
function handleRequest(res) {
// ... in your server handler ...
const stream = renderToPipeableStream(<App />, {
onShellReady() {
res.statusCode = 200;
res.setHeader('Content-type', 'text/html');
stream.pipe(res);
},
// ...
});
}
API
react-dom
See https://react.dev/reference/react-dom
react-dom/client
See https://react.dev/reference/react-dom/client