@@ -77,7 +80,7 @@ export function TeamMember({
{threads && (
)}
diff --git a/src/components/PageHeading.tsx b/src/components/PageHeading.tsx
index 659295d0a..6000c8e51 100644
--- a/src/components/PageHeading.tsx
+++ b/src/components/PageHeading.tsx
@@ -22,7 +22,6 @@ function PageHeading({
title,
status,
canary,
- description,
tags = [],
breadcrumbs,
}: PageHeadingProps) {
@@ -40,11 +39,6 @@ function PageHeading({
)}
{status ?
{tags.map((tag) => (
diff --git a/src/components/Search.tsx b/src/components/Search.tsx
index 8bc47297a..f5c963f67 100644
--- a/src/components/Search.tsx
+++ b/src/components/Search.tsx
@@ -94,7 +94,17 @@ export function Search({
onOpen,
onClose,
searchParameters = {
- hitsPerPage: 5,
+ hitsPerPage: 30,
+ attributesToHighlight: [
+ 'hierarchy.lvl0',
+ 'hierarchy.lvl1',
+ 'hierarchy.lvl2',
+ 'hierarchy.lvl3',
+ 'hierarchy.lvl4',
+ 'hierarchy.lvl5',
+ 'hierarchy.lvl6',
+ 'content',
+ ],
},
}: SearchProps) {
useDocSearchKeyboardEvents({isOpen, onOpen, onClose});
@@ -110,7 +120,6 @@ export function Search({
createPortal(
- {deployedTranslations.map((languageCode) => (
+ {finishedTranslations.map((languageCode) => (
- {name} {isPacked && '✔'}
+ {name} {isPacked && '✅'}
);
}
@@ -304,7 +307,7 @@ export default function PackingList() {
function Item({ name, isPacked }) {
return (
- {name} {isPacked ? '✔' : '❌'}
+ {name} {isPacked ? '✅' : '❌'}
);
}
@@ -610,7 +613,7 @@ We hope that this approach will make the API reference useful not only as a way
## What's next? {/*whats-next*/}
-That's a wrap for our little tour! Have a look around the new website, see what you like or don't like, and keep the feedback coming in the [anonymous survey](https://www.surveymonkey.co.uk/r/PYRPF3X) or in our [issue tracker](https://github.com/reactjs/reactjs.org/issues).
+That's a wrap for our little tour! Have a look around the new website, see what you like or don't like, and keep the feedback coming in our [issue tracker](https://github.com/reactjs/react.dev/issues).
We acknowledge this project has taken a long time to ship. We wanted to maintain a high quality bar that the React community deserves. While writing these docs and creating all of the examples, we found mistakes in some of our own explanations, bugs in React, and even gaps in the React design that we are now working to address. We hope that the new documentation will help us hold React itself to a higher bar in the future.
diff --git a/src/content/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023.md b/src/content/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023.md
index 1f6b911e1..aeb677f31 100644
--- a/src/content/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023.md
+++ b/src/content/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023.md
@@ -1,5 +1,8 @@
---
title: "React Labs: What We've Been Working On – March 2023"
+author: Joseph Savona, Josh Story, Lauren Tan, Mengdi Chen, Samuel Susla, Sathya Gunasekaran, Sebastian Markbage, and Andrew Clark
+date: 2023/03/22
+description: In React Labs posts, we write about projects in active research and development. We've made significant progress on them since our last update, and we'd like to share what we learned.
---
March 22, 2023 by [Joseph Savona](https://twitter.com/en_JS), [Josh Story](https://twitter.com/joshcstory), [Lauren Tan](https://twitter.com/potetotes), [Mengdi Chen](https://twitter.com/mengdi_en), [Samuel Susla](https://twitter.com/SamuelSusla), [Sathya Gunasekaran](https://twitter.com/_gsathya), [Sebastian Markbåge](https://twitter.com/sebmarkbage), and [Andrew Clark](https://twitter.com/acdlite)
diff --git a/src/content/blog/2023/05/03/react-canaries.md b/src/content/blog/2023/05/03/react-canaries.md
index 81da3fd00..19d9960b0 100644
--- a/src/content/blog/2023/05/03/react-canaries.md
+++ b/src/content/blog/2023/05/03/react-canaries.md
@@ -1,5 +1,8 @@
---
title: "React Canaries: Enabling Incremental Feature Rollout Outside Meta"
+author: Dan Abramov, Sophie Alpert, Rick Hanlon, Sebastian Markbage, and Andrew Clark
+date: 2023/05/03
+description: We'd like to offer the React community an option to adopt individual new features as soon as their design is close to final, before they're released in a stable version--similar to how Meta has long used bleeding-edge versions of React internally. We are introducing a new officially supported [Canary release channel](/community/versioning-policy#canary-channel). It lets curated setups like frameworks decouple adoption of individual React features from the React release schedule.
---
May 3, 2023 by [Dan Abramov](https://twitter.com/dan_abramov), [Sophie Alpert](https://twitter.com/sophiebits), [Rick Hanlon](https://twitter.com/rickhanlonii), [Sebastian Markbåge](https://twitter.com/sebmarkbage), and [Andrew Clark](https://twitter.com/acdlite)
diff --git a/src/content/blog/2024/02/15/react-labs-what-we-have-been-working-on-february-2024.md b/src/content/blog/2024/02/15/react-labs-what-we-have-been-working-on-february-2024.md
index 03fc85c37..fee21f4ec 100644
--- a/src/content/blog/2024/02/15/react-labs-what-we-have-been-working-on-february-2024.md
+++ b/src/content/blog/2024/02/15/react-labs-what-we-have-been-working-on-february-2024.md
@@ -1,5 +1,8 @@
---
title: "React Labs: What We've Been Working On – February 2024"
+author: Joseph Savona, Ricky Hanlon, Andrew Clark, Matt Carroll, and Dan Abramov
+date: 2024/02/15
+description: In React Labs posts, we write about projects in active research and development. We’ve made significant progress since our last update, and we’d like to share our progress.
---
February 15, 2024 by [Joseph Savona](https://twitter.com/en_JS), [Ricky Hanlon](https://twitter.com/rickhanlonii), [Andrew Clark](https://twitter.com/acdlite), [Matt Carroll](https://twitter.com/mattcarrollcode), and [Dan Abramov](https://twitter.com/dan_abramov).
@@ -52,7 +55,7 @@ We refer to this broader collection of features as simply "Actions". Actions all
```
-The `action` function can operate synchronously or asynchronously. You can define them on the client side using standard JavaScript or on the server with the [`'use server'`](/reference/react/use-server) directive. When using an action, React will manage the life cycle of the data submission for you, providing hooks like [`useFormStatus`](/reference/react-dom/hooks/useFormStatus), and [`useFormState`](/reference/react-dom/hooks/useFormState) to access the current state and response of the form action.
+The `action` function can operate synchronously or asynchronously. You can define them on the client side using standard JavaScript or on the server with the [`'use server'`](/reference/rsc/use-server) directive. When using an action, React will manage the life cycle of the data submission for you, providing hooks like [`useFormStatus`](/reference/react-dom/hooks/useFormStatus), and [`useActionState`](/reference/react/useActionState) to access the current state and response of the form action.
By default, Actions are submitted within a [transition](/reference/react/useTransition), keeping the current page interactive while the action is processing. Since Actions support async functions, we've also added the ability to use `async/await` in transitions. This allows you to show pending UI with the `isPending` state of a transition when an async request like `fetch` starts, and show the pending UI all the way through the update being applied.
@@ -72,13 +75,13 @@ Canaries are a change to the way we develop React. Previously, features would be
React Server Components, Asset Loading, Document Metadata, and Actions have all landed in the React Canary, and we've added docs for these features on react.dev:
-- **Directives**: [`"use client"`](/reference/react/use-client) and [`"use server"`](/reference/react/use-server) are bundler features designed for full-stack React frameworks. They mark the "split points" between the two environments: `"use client"` instructs the bundler to generate a `
+```
+
+### Libraries depending on React internals may block upgrades {/*libraries-depending-on-react-internals-may-block-upgrades*/}
+
+This release includes changes to React internals that may impact libraries that ignore our pleas to not use internals like `SECRET_INTERNALS_DO_NOT_USE_OR_YOU_WILL_BE_FIRED`. These changes are necessary to land improvements in React 19, and will not break libraries that follow our guidelines.
+
+Based on our [Versioning Policy](https://react.dev/community/versioning-policy#what-counts-as-a-breaking-change), these updates are not listed as breaking changes, and we are not including docs for how to upgrade them. The recommendation is to remove any code that depends on internals.
+
+To reflect the impact of using internals, we have renamed the `SECRET_INTERNALS` suffix to:
+
+`_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE`
+
+In the future we will more aggressively block accessing internals from React to discourage usage and ensure users are not blocked from upgrading.
+
+## TypeScript changes {/*typescript-changes*/}
+
+### Removed deprecated TypeScript types {/*removed-deprecated-typescript-types*/}
+
+We've cleaned up the TypeScript types based on the removed APIs in React 19. Some of the removed have types been moved to more relevant packages, and others are no longer needed to describe React's behavior.
+
+
+We've published [`types-react-codemod`](https://github.com/eps1lon/types-react-codemod/) to migrate most type related breaking changes:
+
+```bash
+npx types-react-codemod@latest preset-19 ./path-to-app
+```
+
+If you have a lot of unsound access to `element.props`, you can run this additional codemod:
+
+```bash
+npx types-react-codemod@latest react-element-default-any-props ./path-to-your-react-ts-files
+```
+
+
+
+Check out [`types-react-codemod`](https://github.com/eps1lon/types-react-codemod/) for a list of supported replacements. If you feel a codemod is missing, it can be tracked in the [list of missing React 19 codemods](https://github.com/eps1lon/types-react-codemod/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+label%3A%22React+19%22+label%3Aenhancement).
+
+
+### `ref` cleanups required {/*ref-cleanup-required*/}
+
+_This change is included in the `react-19` codemod preset as [`no-implicit-ref-callback-return
+`](https://github.com/eps1lon/types-react-codemod/#no-implicit-ref-callback-return)._
+
+Due to the introduction of ref cleanup functions, returning anything else from a ref callback will now be rejected by TypeScript. The fix is usually to stop using implicit returns:
+
+```diff [[1, 1, "("], [1, 1, ")"], [2, 2, "{", 15], [2, 2, "}", 1]]
+-
(instance = current)} />
++
{instance = current}} />
+```
+
+The original code returned the instance of the `HTMLDivElement` and TypeScript wouldn't know if this was supposed to be a cleanup function or not.
+
+### `useRef` requires an argument {/*useref-requires-argument*/}
+
+_This change is included in the `react-19` codemod preset as [`refobject-defaults`](https://github.com/eps1lon/types-react-codemod/#refobject-defaults)._
+
+A long-time complaint of how TypeScript and React work has been `useRef`. We've changed the types so that `useRef` now requires an argument. This significantly simplifies its type signature. It'll now behave more like `createContext`.
+
+```ts
+// @ts-expect-error: Expected 1 argument but saw none
+useRef();
+// Passes
+useRef(undefined);
+// @ts-expect-error: Expected 1 argument but saw none
+createContext();
+// Passes
+createContext(undefined);
+```
+
+This now also means that all refs are mutable. You'll no longer hit the issue where you can't mutate a ref because you initialised it with `null`:
+
+```ts
+const ref = useRef
(null);
+
+// Cannot assign to 'current' because it is a read-only property
+ref.current = 1;
+```
+
+`MutableRef` is now deprecated in favor of a single `RefObject` type which `useRef` will always return:
+
+```ts
+interface RefObject {
+ current: T
+}
+
+declare function useRef: RefObject
+```
+
+`useRef` still has a convenience overload for `useRef(null)` that automatically returns `RefObject`. To ease migration due to the required argument for `useRef`, a convenience overload for `useRef(undefined)` was added that automatically returns `RefObject`.
+
+Check out [[RFC] Make all refs mutable](https://github.com/DefinitelyTyped/DefinitelyTyped/pull/64772) for prior discussions about this change.
+
+### Changes to the `ReactElement` TypeScript type {/*changes-to-the-reactelement-typescript-type*/}
+
+_This change is included in the [`react-element-default-any-props`](https://github.com/eps1lon/types-react-codemod#react-element-default-any-props) codemod._
+
+The `props` of React elements now default to `unknown` instead of `any` if the element is typed as `ReactElement`. This does not affect you if you pass a type argument to `ReactElement`:
+
+```ts
+type Example2 = ReactElement<{ id: string }>["props"];
+// ^? { id: string }
+```
+
+But if you relied on the default, you now have to handle `unknown`:
+
+```ts
+type Example = ReactElement["props"];
+// ^? Before, was 'any', now 'unknown'
+```
+
+You should only need it if you have a lot of legacy code relying on unsound access of element props. Element introspection only exists as an escape hatch, and you should make it explicit that your props access is unsound via an explicit `any`.
+
+### The JSX namespace in TypeScript {/*the-jsx-namespace-in-typescript*/}
+This change is included in the `react-19` codemod preset as [`scoped-jsx`](https://github.com/eps1lon/types-react-codemod#scoped-jsx)
+
+A long-time request is to remove the global `JSX` namespace from our types in favor of `React.JSX`. This helps prevent pollution of global types which prevents conflicts between different UI libraries that leverage JSX.
+
+You'll now need to wrap module augmentation of the JSX namespace in `declare module "....":
+
+```diff
+// global.d.ts
++ declare module "react" {
+ namespace JSX {
+ interface IntrinsicElements {
+ "my-element": {
+ myElementProps: string;
+ };
+ }
+ }
++ }
+```
+
+The exact module specifier depends on the JSX runtime you specified in the `compilerOptions` of your `tsconfig.json`:
+
+- For `"jsx": "react-jsx"` it would be `react/jsx-runtime`.
+- For `"jsx": "react-jsxdev"` it would be `react/jsx-dev-runtime`.
+- For `"jsx": "react"` and `"jsx": "preserve"` it would be `react`.
+
+### Better `useReducer` typings {/*better-usereducer-typings*/}
+
+`useReducer` now has improved type inference thanks to [@mfp22](https://github.com/mfp22).
+
+However, this required a breaking change where `useReducer` doesn't accept the full reducer type as a type parameter but instead either needs none (and rely on contextual typing) or needs both the state and action type.
+
+The new best practice is _not_ to pass type arguments to `useReducer`.
+```diff
+- useReducer>(reducer)
++ useReducer(reducer)
+```
+This may not work in edge cases where you can explicitly type the state and action, by passing in the `Action` in a tuple:
+```diff
+- useReducer>(reducer)
++ useReducer(reducer)
+```
+If you define the reducer inline, we encourage to annotate the function parameters instead:
+```diff
+- useReducer>((state, action) => state)
++ useReducer((state: State, action: Action) => state)
+```
+This is also what you'd also have to do if you move the reducer outside of the `useReducer` call:
+
+```ts
+const reducer = (state: State, action: Action) => state;
+```
+
+## Changelog {/*changelog*/}
+
+### Other breaking changes {/*other-breaking-changes*/}
+
+- **react-dom**: Error for javascript URLs in src/href [#26507](https://github.com/facebook/react/pull/26507)
+- **react-dom**: Remove `errorInfo.digest` from `onRecoverableError` [#28222](https://github.com/facebook/react/pull/28222)
+- **react-dom**: Remove `unstable_flushControlled` [#26397](https://github.com/facebook/react/pull/26397)
+- **react-dom**: Remove `unstable_createEventHandle` [#28271](https://github.com/facebook/react/pull/28271)
+- **react-dom**: Remove `unstable_renderSubtreeIntoContainer` [#28271](https://github.com/facebook/react/pull/28271)
+- **react-dom**: Remove `unstable_runWithPrioirty` [#28271](https://github.com/facebook/react/pull/28271)
+- **react-is**: Remove deprecated methods from `react-is` [28224](https://github.com/facebook/react/pull/28224)
+
+### Other notable changes {/*other-notable-changes*/}
+
+- **react**: Batch sync, default and continuous lanes [#25700](https://github.com/facebook/react/pull/25700)
+- **react**: Don't prerender siblings of suspended component [#26380](https://github.com/facebook/react/pull/26380)
+- **react**: Detect infinite update loops caused by render phase updates [#26625](https://github.com/facebook/react/pull/26625)
+- **react-dom**: Transitions in popstate are now synchronous [#26025](https://github.com/facebook/react/pull/26025)
+- **react-dom**: Remove layout effect warning during SSR [#26395](https://github.com/facebook/react/pull/26395)
+- **react-dom**: Warn and don’t set empty string for src/href (except anchor tags) [#28124](https://github.com/facebook/react/pull/28124)
+
+We'll publish the full changelog with the stable release of React 19.
+
+---
+
+Thanks to [Andrew Clark](https://twitter.com/acdlite), [Eli White](https://twitter.com/Eli_White), [Jack Pope](https://github.com/jackpope), [Jan Kassens](https://github.com/kassens), [Josh Story](https://twitter.com/joshcstory), [Matt Carroll](https://twitter.com/mattcarrollcode), [Noah Lemen](https://twitter.com/noahlemen), [Sophie Alpert](https://twitter.com/sophiebits), and [Sebastian Silbermann](https://twitter.com/sebsilbermann) for reviewing and editing this post.
diff --git a/src/content/blog/2024/04/25/react-19.md b/src/content/blog/2024/04/25/react-19.md
new file mode 100644
index 000000000..1b19c3546
--- /dev/null
+++ b/src/content/blog/2024/04/25/react-19.md
@@ -0,0 +1,775 @@
+---
+title: "React 19 RC"
+author: The React Team
+date: 2024/04/25
+description: React 19 RC is now available on npm! In this post, we'll give an overview of the new features in React 19, and how you can adopt them.
+---
+
+April 25, 2024 by [The React Team](/community/team)
+
+---
+
+
+
+React 19 RC is now available on npm!
+
+
+
+In our [React 19 RC Upgrade Guide](/blog/2024/04/25/react-19-upgrade-guide), we shared step-by-step instructions for upgrading your app to React 19. In this post, we'll give an overview of the new features in React 19, and how you can adopt them.
+
+- [What's new in React 19](#whats-new-in-react-19)
+- [Improvements in React 19](#improvements-in-react-19)
+- [How to upgrade](#how-to-upgrade)
+
+For a list of breaking changes, see the [Upgrade Guide](/blog/2024/04/25/react-19-upgrade-guide).
+
+---
+
+## What's new in React 19 {/*whats-new-in-react-19*/}
+
+### Actions {/*actions*/}
+
+A common use case in React apps is to perform a data mutation and then update state in response. For example, when a user submits a form to change their name, you will make an API request, and then handle the response. In the past, you would need to handle pending states, errors, optimistic updates, and sequential requests manually.
+
+For example, you could handle the pending and error state in `useState`:
+
+```js
+// Before Actions
+function UpdateName({}) {
+ const [name, setName] = useState("");
+ const [error, setError] = useState(null);
+ const [isPending, setIsPending] = useState(false);
+
+ const handleSubmit = async () => {
+ setIsPending(true);
+ const error = await updateName(name);
+ setIsPending(false);
+ if (error) {
+ setError(error);
+ return;
+ }
+ redirect("/path");
+ };
+
+ return (
+
+
setName(event.target.value)} />
+
+ {error &&
{error}
}
+
+
setName(event.target.value)} />
+
+ {error &&
{error}
}
+
}>
+
+
+ )
+}
+```
+
+
+
+#### `use` does not support promises created in render. {/*use-does-not-support-promises-created-in-render*/}
+
+If you try to pass a promise created in render to `use`, React will warn:
+
+
+
+
+
+A component was suspended by an uncached promise. Creating promises inside a Client Component or hook is not yet supported, except via a Suspense-compatible library or framework.
+
+
+
+
+
+To fix, you need to pass a promise from a suspense powered library or framework that supports caching for promises. In the future we plan to ship features to make it easier to cache promises in render.
+
+
+
+You can also read context with `use`, allowing you to read Context conditionally such as after early returns:
+
+```js {1,11}
+import {use} from 'react';
+import ThemeContext from './ThemeContext'
+
+function Heading({children}) {
+ if (children == null) {
+ return null;
+ }
+
+ // This would not work with useContext
+ // because of the early return.
+ const theme = use(ThemeContext);
+ return (
+
+ {children}
+
+ );
+}
+```
+
+The `use` API can only be called in render, similar to hooks. Unlike hooks, `use` can be called conditionally. In the future we plan to support more ways to consume resources in render with `use`.
+
+For more information, see the docs for [`use`](/reference/react/use).
+
+
+## React Server Components {/*react-server-components*/}
+
+### Server Components {/*server-components*/}
+
+Server Components are a new option that allows rendering components ahead of time, before bundling, in an environment separate from your client application or SSR server. This separate environment is the "server" in React Server Components. Server Components can run once at build time on your CI server, or they can be run for each request using a web server.
+
+React 19 includes all of the React Server Components features included from the Canary channel. This means libraries that ship with Server Components can now target React 19 as a peer dependency with a `react-server` [export condition](https://github.com/reactjs/rfcs/blob/main/text/0227-server-module-conventions.md#react-server-conditional-exports) for use in frameworks that support the [Full-stack React Architecture](/learn/start-a-new-react-project#which-features-make-up-the-react-teams-full-stack-architecture-vision).
+
+
+
+
+#### How do I build support for Server Components? {/*how-do-i-build-support-for-server-components*/}
+
+While React Server Components in React 19 are stable and will not break between major versions, the underlying APIs used to implement a React Server Components bundler or framework do not follow semver and may break between minors in React 19.x.
+
+To support React Server Components as a bundler or framework, we recommend pinning to a specific React version, or using the Canary release. We will continue working with bundlers and frameworks to stabilize the APIs used to implement React Server Components in the future.
+
+
+
+
+For more, see the docs for [React Server Components](/reference/rsc/server-components).
+
+### Server Actions {/*server-actions*/}
+
+Server Actions allow Client Components to call async functions executed on the server.
+
+When a Server Action is defined with the `"use server"` directive, your framework will automatically create a reference to the server function, and pass that reference to the Client Component. When that function is called on the client, React will send a request to the server to execute the function, and return the result.
+
+
+
+#### There is no directive for Server Components. {/*there-is-no-directive-for-server-components*/}
+
+A common misunderstanding is that Server Components are denoted by `"use server"`, but there is no directive for Server Components. The `"use server"` directive is used for Server Actions.
+
+For more info, see the docs for [Directives](/reference/rsc/directives).
+
+
+
+Server Actions can be created in Server Components and passed as props to Client Components, or they can be imported and used in Client Components.
+
+For more, see the docs for [React Server Actions](/reference/rsc/server-actions).
+
+## Improvements in React 19 {/*improvements-in-react-19*/}
+
+### `ref` as a prop {/*ref-as-a-prop*/}
+
+Starting in React 19, you can now access `ref` as a prop for function components:
+
+```js [[1, 1, "ref"], [1, 2, "ref", 45], [1, 6, "ref", 14]]
+function MyInput({placeholder, ref}) {
+ return
+}
+
+//...
+
+```
+
+New function components will no longer need `forwardRef`, and we will be publishing a codemod to automatically update your components to use the new `ref` prop. In future versions we will deprecate and remove `forwardRef`.
+
+
+
+`refs` passed to classes are not passed as props since they reference the component instance.
+
+
+
+### Diffs for hydration errors {/*diffs-for-hydration-errors*/}
+
+We also improved error reporting for hydration errors in `react-dom`. For example, instead of logging multiple errors in DEV without any information about the mismatch:
+
+
+
+
+
+Warning: Text content did not match. Server: "Server" Client: "Client"
+{' '}at span
+{' '}at App
+
+
+
+
+
+Warning: An error occurred during hydration. The server HTML was replaced with client content in \.
+
+
+
+
+
+Warning: Text content did not match. Server: "Server" Client: "Client"
+{' '}at span
+{' '}at App
+
+
+
+
+
+Warning: An error occurred during hydration. The server HTML was replaced with client content in \.
+
+
+
+
+
+Uncaught Error: Text content does not match server-rendered HTML.
+{' '}at checkForUnmatchedText
+{' '}...
+
+
+
+
+
+We now log a single message with a diff of the mismatch:
+
+
+
+
+
+
+Uncaught Error: Hydration failed because the server rendered HTML didn't match the client. As a result this tree will be regenerated on the client. This can happen if an SSR-ed Client Component used:{'\n'}
+\- A server/client branch `if (typeof window !== 'undefined')`.
+\- Variable input such as `Date.now()` or `Math.random()` which changes each time it's called.
+\- Date formatting in a user's locale which doesn't match the server.
+\- External changing data without sending a snapshot of it along with the HTML.
+\- Invalid HTML tag nesting.{'\n'}
+It can also happen if the client has a browser extension installed which messes with the HTML before React loaded.{'\n'}
+https://react.dev/link/hydration-mismatch {'\n'}
+{' '}\
+{' '}\
+{'+ '}Client
+{'- '}Server{'\n'}
+{' '}at throwOnHydrationMismatch
+{' '}...
+
+
+
+
+
+### `
` as a provider {/*context-as-a-provider*/}
+
+In React 19, you can render `` as a provider instead of ``:
+
+
+```js {5,7}
+const ThemeContext = createContext('');
+
+function App({children}) {
+ return (
+
+ {children}
+
+ );
+}
+```
+
+New Context providers can use `` and we will be publishing a codemod to convert existing providers. In future versions we will deprecate ``.
+
+### Cleanup functions for refs {/*cleanup-functions-for-refs*/}
+
+We now support returning a cleanup function from `ref` callbacks:
+
+```js {7-9}
+ {
+ // ref created
+
+ // NEW: return a cleanup function to reset
+ // the ref when element is removed from DOM.
+ return () => {
+ // ref cleanup
+ };
+ }}
+/>
+```
+
+When the component unmounts, React will call the cleanup function returned from the `ref` callback. This works for DOM refs, refs to class components, and `useImperativeHandle`.
+
+
+
+Previously, React would call `ref` functions with `null` when unmounting the component. If your `ref` returns a cleanup function, React will now skip this step.
+
+In future versions, we will deprecate calling refs with `null` when unmounting components.
+
+
+
+Due to the introduction of ref cleanup functions, returning anything else from a `ref` callback will now be rejected by TypeScript. The fix is usually to stop using implicit returns, for example:
+
+```diff [[1, 1, "("], [1, 1, ")"], [2, 2, "{", 15], [2, 2, "}", 1]]
+- (instance = current)} />
++
{instance = current}} />
+```
+
+The original code returned the instance of the `HTMLDivElement` and TypeScript wouldn't know if this was _supposed_ to be a cleanup function or if you didn't want to return a cleanup function.
+
+You can codemod this pattern with [`no-implicit-ref-callback-return`](https://github.com/eps1lon/types-react-codemod/#no-implicit-ref-callback-return).
+
+### `useDeferredValue` initial value {/*use-deferred-value-initial-value*/}
+
+We've added an `initialValue` option to `useDeferredValue`:
+
+```js [[1, 1, "deferredValue"], [1, 4, "deferredValue"], [2, 4, "''"]]
+function Search({deferredValue}) {
+ // On initial render the value is ''.
+ // Then a re-render is scheduled with the deferredValue.
+ const value = useDeferredValue(deferredValue, '');
+
+ return (
+
+ );
+}
+````
+
+When
initialValue is provided, `useDeferredValue` will return it as `value` for the initial render of the component, and schedules a re-render in the background with the
deferredValue returned.
+
+For more, see [`useDeferredValue`](/reference/react/useDeferredValue).
+
+### Support for Document Metadata {/*support-for-metadata-tags*/}
+
+In HTML, document metadata tags like `
`, `<link>`, and `<meta>` are reserved for placement in the `<head>` section of the document. In React, the component that decides what metadata is appropriate for the app may be very far from the place where you render the `<head>` or React does not render the `<head>` at all. In the past, these elements would need to be inserted manually in an effect, or by libraries like [`react-helmet`](https://github.com/nfl/react-helmet), and required careful handling when server rendering a React application.
+
+In React 19, we're adding support for rendering document metadata tags in components natively:
+
+```js {5-8}
+function BlogPost({post}) {
+ return (
+ <article>
+ <h1>{post.title}</h1>
+ <title>{post.title}
+
+
+
+
+ Eee equals em-see-squared...
+
+
+ );
+}
+```
+
+When React renders this component, it will see the `
` `<link>` and `<meta>` tags, and automatically hoist them to the `<head>` section of document. By supporting these metadata tags natively, we're able to ensure they work with client-only apps, streaming SSR, and Server Components.
+
+<Note>
+
+#### You may still want a Metadata library {/*you-may-still-want-a-metadata-library*/}
+
+For simple use cases, rendering Document Metadata as tags may be suitable, but libraries can offer more powerful features like overriding generic metadata with specific metadata based on the current route. These features make it easier for frameworks and libraries like [`react-helmet`](https://github.com/nfl/react-helmet) to support metadata tags, rather than replace them.
+
+</Note>
+
+For more info, see the docs for [`<title>`](/reference/react-dom/components/title), [`<link>`](/reference/react-dom/components/link), and [`<meta>`](/reference/react-dom/components/meta).
+
+### Support for stylesheets {/*support-for-stylesheets*/}
+
+Stylesheets, both externally linked (`<link rel="stylesheet" href="...">`) and inline (`<style>...</style>`), require careful positioning in the DOM due to style precedence rules. Building a stylesheet capability that allows for composability within components is hard, so users often end up either loading all of their styles far from the components that may depend on them, or they use a style library which encapsulates this complexity.
+
+In React 19, we're addressing this complexity and providing even deeper integration into Concurrent Rendering on the Client and Streaming Rendering on the Server with built in support for stylesheets. If you tell React the `precedence` of your stylesheet it will manage the insertion order of the stylesheet in the DOM and ensure that the stylesheet (if external) is loaded before revealing content that depends on those style rules.
+
+```js {4,5,17}
+function ComponentOne() {
+ return (
+ <Suspense fallback="loading...">
+ <link rel="stylesheet" href="foo" precedence="default" />
+ <link rel="stylesheet" href="bar" precedence="high" />
+ <article class="foo-class bar-class">
+ {...}
+ </article>
+ </Suspense>
+ )
+}
+
+function ComponentTwo() {
+ return (
+ <div>
+ <p>{...}</p>
+ <link rel="stylesheet" href="baz" precedence="default" /> <-- will be inserted between foo & bar
+ </div>
+ )
+}
+```
+
+During Server Side Rendering React will include the stylesheet in the `<head>`, which ensures that the browser will not paint until it has loaded. If the stylesheet is discovered late after we've already started streaming, React will ensure that the stylesheet is inserted into the `<head>` on the client before revealing the content of a Suspense boundary that depends on that stylesheet.
+
+During Client Side Rendering React will wait for newly rendered stylesheets to load before committing the render. If you render this component from multiple places within your application React will only include the stylesheet once in the document:
+
+```js {5}
+function App() {
+ return <>
+ <ComponentOne />
+ ...
+ <ComponentOne /> // won't lead to a duplicate stylesheet link in the DOM
+ </>
+}
+```
+
+For users accustomed to loading stylesheets manually this is an opportunity to locate those stylesheets alongside the components that depend on them allowing for better local reasoning and an easier time ensuring you only load the stylesheets that you actually depend on.
+
+Style libraries and style integrations with bundlers can also adopt this new capability so even if you don't directly render your own stylesheets, you can still benefit as your tools are upgraded to use this feature.
+
+For more details, read the docs for [`<link>`](/reference/react-dom/components/link) and [`<style>`](/reference/react-dom/components/style).
+
+### Support for async scripts {/*support-for-async-scripts*/}
+
+In HTML normal scripts (`<script src="...">`) and deferred scripts (`<script defer="" src="...">`) load in document order which makes rendering these kinds of scripts deep within your component tree challenging. Async scripts (`<script async="" src="...">`) however will load in arbitrary order.
+
+In React 19 we've included better support for async scripts by allowing you to render them anywhere in your component tree, inside the components that actually depend on the script, without having to manage relocating and deduplicating script instances.
+
+```js {4,15}
+function MyComponent() {
+ return (
+ <div>
+ <script async={true} src="..." />
+ Hello World
+ </div>
+ )
+}
+
+function App() {
+ <html>
+ <body>
+ <MyComponent>
+ ...
+ <MyComponent> // won't lead to duplicate script in the DOM
+ </body>
+ </html>
+}
+```
+
+In all rendering environments, async scripts will be deduplicated so that React will only load and execute the script once even if it is rendered by multiple different components.
+
+In Server Side Rendering, async scripts will be included in the `<head>` and prioritized behind more critical resources that block paint such as stylesheets, fonts, and image preloads.
+
+For more details, read the docs for [`<script>`](/reference/react-dom/components/script).
+
+### Support for preloading resources {/*support-for-preloading-resources*/}
+
+During initial document load and on client side updates, telling the Browser about resources that it will likely need to load as early as possible can have a dramatic effect on page performance.
+
+React 19 includes a number of new APIs for loading and preloading Browser resources to make it as easy as possible to build great experiences that aren't held back by inefficient resource loading.
+
+```js
+import { prefetchDNS, preconnect, preload, preinit } from 'react-dom'
+function MyComponent() {
+ preinit('https://.../path/to/some/script.js', {as: 'script' }) // loads and executes this script eagerly
+ preload('https://.../path/to/font.woff', { as: 'font' }) // preloads this font
+ preload('https://.../path/to/stylesheet.css', { as: 'style' }) // preloads this stylesheet
+ prefetchDNS('https://...') // when you may not actually request anything from this host
+ preconnect('https://...') // when you will request something but aren't sure what
+}
+```
+```html
+<!-- the above would result in the following DOM/HTML -->
+<html>
+ <head>
+ <!-- links/scripts are prioritized by their utility to early loading, not call order -->
+ <link rel="prefetch-dns" href="https://...">
+ <link rel="preconnect" href="https://...">
+ <link rel="preload" as="font" href="https://.../path/to/font.woff">
+ <link rel="preload" as="style" href="https://.../path/to/stylesheet.css">
+ <script async="" src="https://.../path/to/some/script.js"></script>
+ </head>
+ <body>
+ ...
+ </body>
+</html>
+```
+
+These APIs can be used to optimize initial page loads by moving discovery of additional resources like fonts out of stylesheet loading. They can also make client updates faster by prefetching a list of resources used by an anticipated navigation and then eagerly preloading those resources on click or even on hover.
+
+For more details see [Resource Preloading APIs](/reference/react-dom#resource-preloading-apis).
+
+### Compatibility with third-party scripts and extensions {/*compatibility-with-third-party-scripts-and-extensions*/}
+
+We've improved hydration to account for third-party scripts and browser extensions.
+
+When hydrating, if an element that renders on the client doesn't match the element found in the HTML from the server, React will force a client re-render to fix up the content. Previously, if an element was inserted by third-party scripts or browser extensions, it would trigger a mismatch error and client render.
+
+In React 19, unexpected tags in the `<head>` and `<body>` will be skipped over, avoiding the mismatch errors. If React needs to re-render the entire document due to an unrelated hydration mismatch, it will leave in place stylesheets inserted by third-party scripts and browser extensions.
+
+### Better error reporting {/*error-handling*/}
+
+We improved error handling in React 19 to remove duplication and provide options for handling caught and uncaught errors. For example, when there's an error in render caught by an Error Boundary, previously React would throw the error twice (once for the original error, then again after failing to automatically recover), and then call `console.error` with info about where the error occurred.
+
+This resulted in three errors for every caught error:
+
+<ConsoleBlockMulti>
+
+<ConsoleLogLine level="error">
+
+Uncaught Error: hit
+{' '}at Throws
+{' '}at renderWithHooks
+{' '}...
+
+</ConsoleLogLine>
+
+<ConsoleLogLine level="error">
+
+Uncaught Error: hit<span className="ms-2 text-gray-30">{' <--'} Duplicate</span>
+{' '}at Throws
+{' '}at renderWithHooks
+{' '}...
+
+</ConsoleLogLine>
+
+<ConsoleLogLine level="error">
+
+The above error occurred in the Throws component:
+{' '}at Throws
+{' '}at ErrorBoundary
+{' '}at App{'\n'}
+React will try to recreate this component tree from scratch using the error boundary you provided, ErrorBoundary.
+
+</ConsoleLogLine>
+
+</ConsoleBlockMulti>
+
+In React 19, we log a single error with all the error information included:
+
+<ConsoleBlockMulti>
+
+<ConsoleLogLine level="error">
+
+Error: hit
+{' '}at Throws
+{' '}at renderWithHooks
+{' '}...{'\n'}
+The above error occurred in the Throws component:
+{' '}at Throws
+{' '}at ErrorBoundary
+{' '}at App{'\n'}
+React will try to recreate this component tree from scratch using the error boundary you provided, ErrorBoundary.
+{' '}at ErrorBoundary
+{' '}at App
+
+</ConsoleLogLine>
+
+</ConsoleBlockMulti>
+
+Additionally, we've added two new root options to complement `onRecoverableError`:
+
+- `onCaughtError`: called when React catches an error in an Error Boundary.
+- `onUncaughtError`: called when an error is thrown and not caught by an Error Boundary.
+- `onRecoverableError`: called when an error is thrown and automatically recovered.
+
+For more info and examples, see the docs for [`createRoot`](/reference/react-dom/client/createRoot) and [`hydrateRoot`](/reference/react-dom/client/hydrateRoot).
+
+### Support for Custom Elements {/*support-for-custom-elements*/}
+
+React 19 adds full support for custom elements and passes all tests on [Custom Elements Everywhere](https://custom-elements-everywhere.com/).
+
+In past versions, using Custom Elements in React has been difficult because React treated unrecognized props as attributes rather than properties. In React 19, we've added support for properties that works on the client and during SSR with the following strategy:
+
+- **Server Side Rendering**: props passed to a custom element will render as attributes if their type is a primitive value like `string`, `number`, or the value is `true`. Props with non-primitive types like `object`, `symbol`, `function`, or value `false` will be omitted.
+- **Client Side Rendering**: props that match a property on the Custom Element instance will be assigned as properties, otherwise they will be assigned as attributes.
+
+Thanks to [Joey Arhar](https://github.com/josepharhar) for driving the design and implementation of Custom Element support in React.
+
+
+#### How to upgrade {/*how-to-upgrade*/}
+See the [React 19 Upgrade Guide](/blog/2024/04/25/react-19-upgrade-guide) for step-by-step instructions and a full list of breaking and notable changes.
+
+
+
diff --git a/src/content/blog/2024/05/22/react-conf-2024-recap.md b/src/content/blog/2024/05/22/react-conf-2024-recap.md
new file mode 100644
index 000000000..96417fd8b
--- /dev/null
+++ b/src/content/blog/2024/05/22/react-conf-2024-recap.md
@@ -0,0 +1,124 @@
+---
+title: "React Conf 2024 Recap"
+author: Ricky Hanlon
+date: 2024/05/22
+description: Last week we hosted React Conf 2024, a two-day conference in Henderson, Nevada where 700+ attendees gathered in-person to discuss the latest in UI engineering. In this post, we'll summarize the talks and announcements from the event.
+---
+
+May 22, 2024 by [Ricky Hanlon](https://twitter.com/rickhanlonii).
+
+---
+
+<Intro>
+
+Last week we hosted React Conf 2024, a two-day conference in Henderson, Nevada where 700+ attendees gathered in-person to discuss the latest in UI engineering. This was our first in-person conference since 2019, and we were thrilled to be able to bring the community together again.
+
+</Intro>
+
+---
+
+At React Conf 2024, we announced the [React 19 RC](/blog/2024/04/25/react-19), the [React Native New Architecture Beta](https://github.com/reactwg/react-native-new-architecture/discussions/189), and an experimental release of the [React Compiler](/learn/react-compiler). The community also took the stage to announce [React Router v7](https://remix.run/blog/merging-remix-and-react-router), [Universal Server Components](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=20765s) in Expo Router, React Server Components in [RedwoodJS](https://redwoodjs.com/blog/rsc-now-in-redwoodjs), and much more.
+
+The entire [day 1](https://www.youtube.com/watch?v=T8TZQ6k4SLE) and [day 2](https://www.youtube.com/watch?v=0ckOUBiuxVY) streams are available online. In this post, we'll summarize the talks and announcements from the event.
+
+## Day 1 {/*day-1*/}
+
+_[Watch the full day 1 stream here.](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=973s)_
+
+To kick off day 1, Meta CTO [Andrew "Boz" Bosworth](https://www.threads.net/@boztank) shared a welcome message followed by an introduction by [Seth Webster](https://twitter.com/sethwebster), who manages the React Org at Meta, and our MC [Ashley Narcisse](https://twitter.com/_darkfadr).
+
+In the day 1 keynote, [Joe Savona](https://twitter.com/en_JS) shared our goals and vision for React to make it easy for anyone to build great user experiences. [Lauren Tan](https://twitter.com/potetotes) followed with a State of React, where she shared that React was downloaded over 1 billion times in 2023, and that 37% of new developers learn to program with React. Finally, she highlighted the work of the React community to make React, React.
+
+For more, check out these talks from the community later in the conference:
+
+- [Vanilla React](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=5542s) by [Ryan Florence](https://twitter.com/ryanflorence)
+- [React Rhythm & Blues](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=12728s) by [Lee Robinson](https://twitter.com/leeerob)
+- [RedwoodJS, now with React Server Components](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=26815s) by [Amy Dutton](https://twitter.com/selfteachme)
+- [Introducing Universal React Server Components in Expo Router](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=20765s) by [Evan Bacon](https://twitter.com/Baconbrix)
+
+Next in the keynote, [Josh Story](https://twitter.com/joshcstory) and [Andrew Clark](https://twitter.com/acdlite) shared new features coming in React 19, and announced the React 19 RC which is ready for testing in production. Check out all the features in the [React 19 release post](/blog/2024/04/25/react-19), and see these talks for deep dives on the new features:
+
+- [What's new in React 19](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=8880s) by [Lydia Hallie](https://twitter.com/lydiahallie)
+- [React Unpacked: A Roadmap to React 19](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=10112s) by [Sam Selikoff](https://twitter.com/samselikoff)
+- [React 19 Deep Dive: Coordinating HTML](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=24916s) by [Josh Story](https://twitter.com/joshcstory)
+- [Enhancing Forms with React Server Components](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=25280s) by [Aurora Walberg Scharff](https://twitter.com/aurorascharff)
+- [React for Two Computers](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=18825s) by [Dan Abramov](https://twitter.com/dan_abramov2)
+- [And Now You Understand React Server Components](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=11256s) by [Kent C. Dodds](https://twitter.com/kentcdodds)
+
+Finally, we ended the keynote with [Joe Savona](https://twitter.com/en_JS), [Sathya Gunasekaran](https://twitter.com/_gsathya), and [Mofei Zhang](https://twitter.com/zmofei) announcing that the React Compiler is now [Open Source](https://github.com/facebook/react/pull/29061), and sharing an experimental version of the React Compiler to try out.
+
+For more information on using the Compiler and how it works, check out [the docs](/learn/react-compiler) and these talks:
+
+- [Forget About Memo](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=12020s) by [Lauren Tan](https://twitter.com/potetotes)
+- [React Compiler Deep Dive](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=9313s) by [Sathya Gunasekaran](https://twitter.com/_gsathya) and [Mofei Zhang](https://twitter.com/zmofei)
+
+Watch the full day 1 keynote here:
+
+<YouTubeIframe src="https://www.youtube.com/embed/T8TZQ6k4SLE?t=973s" />
+
+## Day 2 {/*day-2*/}
+
+_[Watch the full day 2 stream here.](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=1720s)_
+
+To kick off day 2, [Seth Webster](https://twitter.com/sethwebster) shared a welcome message, followed by a Thank You from [Eli White](https://x.com/Eli_White) and an introduction by our Chief Vibes Officer [Ashley Narcisse](https://twitter.com/_darkfadr).
+
+In the day 2 keynote, [Nicola Corti](https://twitter.com/cortinico) shared the State of React Native, including 78 million downloads in 2023. He also highlighted apps using React Native including 2000+ screens used inside of Meta; the product details page in Facebook Marketplace, which is visited more than 2 billion times per day; and part of the Microsoft Windows Start Menu and some features in almost every Microsoft Office product across mobile and desktop.
+
+Nicola also highlighted all the work the community does to support React Native including libraries, frameworks, and multiple platforms. For more, check out these talks from the community:
+
+- [Extending React Native beyond Mobile and Desktop Apps](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=5798s) by [Chris Traganos](https://twitter.com/chris_trag) and [Anisha Malde](https://twitter.com/anisha_malde)
+- [Spatial computing with React](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=22525s) by [Michał Pierzchała](https://twitter.com/thymikee)
+
+[Riccardo Cipolleschi](https://twitter.com/cipolleschir) continued the day 2 keynote by announcing that the React Native New Architecture is now in Beta and ready for apps to adopt in production. He shared new features and improvements in the new architecture, and shared the roadmap for the future of React Native. For more check out:
+
+- [Cross Platform React](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=26569s) by [Olga Zinoveva](https://github.com/SlyCaptainFlint) and [Naman Goel](https://twitter.com/naman34)
+
+Next in the keynote, Nicola announced that we are now recommending starting with a framework like Expo for all new apps created with React Native. With the change, he also announced a new React Native homepage and new Getting Started docs. You can view the new Getting Started guide in the [React Native docs](https://reactnative.dev/docs/next/environment-setup).
+
+Finally, to end the keynote, [Kadi Kraman](https://twitter.com/kadikraman) shared the latest features and improvements in Expo, and how to get started developing with React Native using Expo.
+
+Watch the full day 2 keynote here:
+
+<YouTubeIframe src="https://www.youtube.com/embed/0ckOUBiuxVY?t=1720s" />
+
+## Q&A {/*q-and-a*/}
+
+The React and React Native teams also ended each day with a Q&A session:
+
+- [React Q&A](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=27518s) hosted by [Michael Chan](https://twitter.com/chantastic)
+- [React Native Q&A](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=27935s) hosted by [Jamon Holmgren](https://twitter.com/jamonholmgren)
+
+## And more... {/*and-more*/}
+
+We also heard talks on accessibility, error reporting, css, and more:
+
+- [Demystifying accessibility in React apps](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=20655s) by [Kateryna Porshnieva](https://twitter.com/krambertech)
+- [Pigment CSS, CSS in the server component age](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=21696s) by [Olivier Tassinari](https://twitter.com/olivtassinari)
+- [Real-time React Server Components](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=24070s) by [Sunil Pai](https://twitter.com/threepointone)
+- [Let's break React Rules](https://www.youtube.com/watch?v=T8TZQ6k4SLE&t=25862s) by [Charlotte Isambert](https://twitter.com/c_isambert)
+- [Solve 100% of your errors](https://www.youtube.com/watch?v=0ckOUBiuxVY&t=19881s) by [Ryan Albrecht](https://github.com/ryan953)
+
+## Thank you {/*thank-you*/}
+
+Thank you to all the staff, speakers, and participants who made React Conf 2024 possible. There are too many to list, but we want to thank a few in particular.
+
+Thank you to [Barbara Markiewicz](https://twitter.com/barbara_markie), the team at [Callstack](https://www.callstack.com/), and our React Team Developer Advocate [Matt Carroll](https://twitter.com/mattcarrollcode) for helping to plan the entire event; and to [Sunny Leggett](https://zeroslopeevents.com/about) and everyone from [Zero Slope](https://zeroslopeevents.com) for helping to organize the event.
+
+Thank you [Ashley Narcisse](https://twitter.com/_darkfadr) for being our MC and Chief Vibes Officer; and to [Michael Chan](https://twitter.com/chantastic) and [Jamon Holmgren](https://twitter.com/jamonholmgren) for hosting the Q&A sessions.
+
+Thank you [Seth Webster](https://twitter.com/sethwebster) and [Eli White](https://x.com/Eli_White) for welcoming us each day and providing direction on structure and content; and to [Tom Occhino](https://twitter.com/tomocchino) for joining us with a special message during the after-party.
+
+Thank you [Ricky Hanlon](https://www.youtube.com/watch?v=FxTZL2U-uKg&t=1263s) for providing detailed feedback on talks, working on slide designs, and generally filling in the gaps to sweat the details.
+
+Thank you [Callstack](https://www.callstack.com/) for building the conference website; and to [Kadi Kraman](https://twitter.com/kadikraman) and the [Expo](https://expo.dev/) team for building the conference mobile app.
+
+Thank you to all the sponsors who made the event possible: [Remix](https://remix.run/), [Amazon](https://developer.amazon.com/apps-and-games?cmp=US_2024_05_3P_React-Conf-2024&ch=prtnr&chlast=prtnr&pub=ref&publast=ref&type=org&typelast=org), [MUI](https://mui.com/), [Sentry](https://sentry.io/for/react/?utm_source=sponsored-conf&utm_medium=sponsored-event&utm_campaign=frontend-fy25q2-evergreen&utm_content=logo-reactconf2024-learnmore), [Abbott](https://www.jobs.abbott/software), [Expo](https://expo.dev/), [RedwoodJS](https://redwoodjs.com/), and [Vercel](https://vercel.com).
+
+Thank you to the AV Team for the visuals, stage, and sound; and to the Westin Hotel for hosting us.
+
+Thank you to all the speakers who shared their knowledge and experiences with the community.
+
+Finally, thank you to everyone who attended in person and online to show what makes React, React. React is more than a library, it is a community, and it was inspiring to see everyone come together to share and learn together.
+
+See you next time!
+
diff --git a/src/content/blog/2024/10/21/react-compiler-beta-release.md b/src/content/blog/2024/10/21/react-compiler-beta-release.md
new file mode 100644
index 000000000..f5a870b22
--- /dev/null
+++ b/src/content/blog/2024/10/21/react-compiler-beta-release.md
@@ -0,0 +1,126 @@
+---
+title: "React Compiler Beta Release"
+author: Lauren Tan
+date: 2024/10/21
+description: At React Conf 2024, we announced the experimental release of React Compiler, a build-time tool that optimizes your React app through automatic memoization. In this post, we want to share what's next for open source, and our progress on the compiler.
+
+---
+
+October 21, 2024 by [Lauren Tan](https://twitter.com/potetotes).
+
+---
+
+<Intro>
+
+The React team is excited to share new updates:
+
+</Intro>
+
+1. We're publishing React Compiler Beta today, so that early adopters and library maintainers can try it and provide feedback.
+2. We're officially supporting React Compiler for apps on React 17+, through an optional `react-compiler-runtime` package.
+3. We're opening up public membership of the [React Compiler Working Group](https://github.com/reactwg/react-compiler) to prepare the community for gradual adoption of the compiler.
+
+---
+
+At [React Conf 2024](/blog/2024/05/22/react-conf-2024-recap), we announced the experimental release of React Compiler, a build-time tool that optimizes your React app through automatic memoization. [You can find an introduction to React Compiler here](/learn/react-compiler).
+
+Since the first release, we've fixed numerous bugs reported by the React community, received several high quality bug fixes and contributions[^1] to the compiler, made the compiler more resilient to the broad diversity of JavaScript patterns, and have continued to roll out the compiler more widely at Meta.
+
+In this post, we want to share what's next for React Compiler.
+
+## Try React Compiler Beta today {/*try-react-compiler-beta-today*/}
+
+At [React India 2024](https://www.youtube.com/watch?v=qd5yk2gxbtg), we shared an update on React Compiler. Today, we are excited to announce a new Beta release of React Compiler and ESLint plugin. New betas are published to npm using the `@beta` tag.
+
+To install React Compiler Beta:
+
+<TerminalBlock>
+npm install -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+Or, if you're using Yarn:
+
+<TerminalBlock>
+yarn add -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+You can watch [Sathya Gunasekaran's](https://twitter.com/_gsathya) talk at React India here:
+
+<YouTubeIframe src="https://www.youtube.com/embed/qd5yk2gxbtg" />
+
+## We recommend everyone use the React Compiler linter today {/*we-recommend-everyone-use-the-react-compiler-linter-today*/}
+
+React Compiler’s ESLint plugin helps developers proactively identify and correct [Rules of React](/reference/rules) violations. **We strongly recommend everyone use the linter today**. The linter does not require that you have the compiler installed, so you can use it independently, even if you are not ready to try out the compiler.
+
+To install the linter only:
+
+<TerminalBlock>
+npm install -D eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+Or, if you're using Yarn:
+
+<TerminalBlock>
+yarn add -D eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+After installation you can enable the linter by [adding it to your ESLint config](/learn/react-compiler#installing-eslint-plugin-react-compiler). Using the linter helps identify Rules of React breakages, making it easier to adopt the compiler when it's fully released.
+
+## Backwards Compatibility {/*backwards-compatibility*/}
+
+React Compiler produces code that depends on runtime APIs added in React 19, but we've since added support for the compiler to also work with React 17 and 18. If you are not on React 19 yet, in the Beta release you can now try out React Compiler by specifying a minimum `target` in your compiler config, and adding `react-compiler-runtime` as a dependency. [You can find docs on this here](/learn/react-compiler#using-react-compiler-with-react-17-or-18).
+
+## Using React Compiler in libraries {/*using-react-compiler-in-libraries*/}
+
+Our initial release was focused on identifying major issues with using the compiler in applications. We've gotten great feedback and have substantially improved the compiler since then. We're now ready for broad feedback from the community, and for library authors to try out the compiler to improve performance and the developer experience of maintaining your library.
+
+React Compiler can also be used to compile libraries. Because React Compiler needs to run on the original source code prior to any code transformations, it is not possible for an application's build pipeline to compile the libraries they use. Hence, our recommendation is for library maintainers to independently compile and test their libraries with the compiler, and ship compiled code to npm.
+
+Because your code is pre-compiled, users of your library will not need to have the compiler enabled in order to benefit from the automatic memoization applied to your library. If your library targets apps not yet on React 19, specify a minimum `target` and add `react-compiler-runtime` as a direct dependency. The runtime package will use the correct implementation of APIs depending on the application's version, and polyfill the missing APIs if necessary.
+
+[You can find more docs on this here.](/learn/react-compiler#using-the-compiler-on-libraries)
+
+## Opening up React Compiler Working Group to everyone {/*opening-up-react-compiler-working-group-to-everyone*/}
+
+We previously announced the invite-only [React Compiler Working Group](https://github.com/reactwg/react-compiler) at React Conf to provide feedback, ask questions, and collaborate on the compiler's experimental release.
+
+From today, together with the Beta release of React Compiler, we are opening up Working Group membership to everyone. The goal of the React Compiler Working Group is to prepare the ecosystem for a smooth, gradual adoption of React Compiler by existing applications and libraries. Please continue to file bug reports in the [React repo](https://github.com/facebook/react), but please leave feedback, ask questions, or share ideas in the [Working Group discussion forum](https://github.com/reactwg/react-compiler/discussions).
+
+The core team will also use the discussions repo to share our research findings. As the Stable Release gets closer, any important information will also be posted on this forum.
+
+## React Compiler at Meta {/*react-compiler-at-meta*/}
+
+At [React Conf](/blog/2024/05/22/react-conf-2024-recap), we shared that our rollout of the compiler on Quest Store and Instagram were successful. Since then, we've deployed React Compiler across several more major web apps at Meta, including [Facebook](https://www.facebook.com) and [Threads](https://www.threads.net). That means if you've used any of these apps recently, you may have had your experience powered by the compiler. We were able to onboard these apps onto the compiler with few code changes required, in a monorepo with more than 100,000 React components.
+
+We've seen notable performance improvements across all of these apps. As we've rolled out, we're continuing to see results on the order of [the wins we shared previously at ReactConf](https://youtu.be/lyEKhv8-3n0?t=3223). These apps have already been heavily hand tuned and optimized by Meta engineers and React experts over the years, so even improvements on the order of a few percent are a huge win for us.
+
+We also expected developer productivity wins from React Compiler. To measure this, we collaborated with our data science partners at Meta[^2] to conduct a thorough statistical analysis of the impact of manual memoization on productivity. Before rolling out the compiler at Meta, we discovered that only about 8% of React pull requests used manual memoization and that these pull requests took 31-46% longer to author[^3]. This confirmed our intuition that manual memoization introduces cognitive overhead, and we anticipate that React Compiler will lead to more efficient code authoring and review. Notably, React Compiler also ensures that *all* code is memoized by default, not just the (in our case) 8% where developers explicitly apply memoization.
+
+## Roadmap to Stable {/*roadmap-to-stable*/}
+
+*This is not a final roadmap, and is subject to change.*
+
+We intend to ship a Release Candidate of the compiler in the near future following the Beta release, when the majority of apps and libraries that follow the Rules of React have been proven to work well with the compiler. After a period of final feedback from the community, we plan on a Stable Release for the compiler. The Stable Release will mark the beginning of a new foundation for React, and all apps and libraries will be strongly recommended to use the compiler and ESLint plugin.
+
+* ✅ Experimental: Released at React Conf 2024, primarily for feedback from early adopters.
+* ✅ Public Beta: Available today, for feedback from the wider community.
+* 🚧 Release Candidate (RC): React Compiler works for the majority of rule-following apps and libraries without issue.
+* 🚧 General Availability: After final feedback period from the community.
+
+These releases also include the compiler's ESLint plugin, which surfaces diagnostics statically analyzed by the compiler. We plan to combine the existing eslint-plugin-react-hooks plugin with the compiler's ESLint plugin, so only one plugin needs to be installed.
+
+Post-Stable, we plan to add more compiler optimizations and improvements. This includes both continual improvements to automatic memoization, and new optimizations altogether, with minimal to no change of product code. Upgrading to each new release of the compiler is aimed to be straightforward, and each upgrade will continue to improve performance and add better handling of diverse JavaScript and React patterns.
+
+Throughout this process, we also plan to prototype an IDE extension for React. It is still very early in research, so we expect to be able to share more of our findings with you in a future React Labs blog post.
+
+---
+
+Thanks to [Sathya Gunasekaran](https://twitter.com/_gsathya), [Joe Savona](https://twitter.com/en_JS), [Ricky Hanlon](https://twitter.com/rickhanlonii), [Alex Taylor](https://github.com/alexmckenley), [Jason Bonta](https://twitter.com/someextent), and [Eli White](https://twitter.com/Eli_White) for reviewing and editing this post.
+
+---
+
+[^1]: Thanks [@nikeee](https://github.com/facebook/react/pulls?q=is%3Apr+author%3Anikeee), [@henryqdineen](https://github.com/facebook/react/pulls?q=is%3Apr+author%3Ahenryqdineen), [@TrickyPi](https://github.com/facebook/react/pulls?q=is%3Apr+author%3ATrickyPi), and several others for their contributions to the compiler.
+
+[^2]: Thanks [Vaishali Garg](https://www.linkedin.com/in/vaishaligarg09) for leading this study on React Compiler at Meta, and for reviewing this post.
+
+[^3]: After controlling on author tenure, diff length/complexity, and other potential confounding factors.
\ No newline at end of file
diff --git a/src/content/blog/index.md b/src/content/blog/index.md
index 409f33701..e37631e80 100644
--- a/src/content/blog/index.md
+++ b/src/content/blog/index.md
@@ -10,6 +10,30 @@ This blog is the official source for the updates from the React team. Anything i
<div className="sm:-mx-5 flex flex-col gap-5 mt-12">
+<BlogCard title="React Compiler Beta Release" date="October 21, 2024" url="/blog/2024/10/21/react-compiler-beta-release">
+
+We announced an experimental release of React Compiler at React Conf 2024. We've made a lot of progress since then, and in this post we want to share what's next for React Compiler ...
+
+</BlogCard>
+
+<BlogCard title="React Conf 2024 Recap" date="May 22, 2024" url="/blog/2024/05/22/react-conf-2024-recap">
+
+Last week we hosted React Conf 2024, a two-day conference in Henderson, Nevada where 700+ attendees gathered in-person to discuss the latest in UI engineering. This was our first in-person conference since 2019, and we were thrilled to be able to bring the community together again ...
+
+</BlogCard>
+
+<BlogCard title="React 19 RC " date="April 25, 2024" url="/blog/2024/04/25/react-19">
+
+In the React 19 RC Upgrade Guide, we shared step-by-step instructions for upgrading your app to React 19. In this post, we'll give an overview of the new features in React 19, and how you can adopt them ...
+
+</BlogCard>
+
+<BlogCard title="React 19 RC Upgrade Guide" date="April 25, 2024" url="/blog/2024/04/25/react-19-upgrade-guide">
+
+The improvements added to React 19 require some breaking changes, but we've worked to make the upgrade as smooth as possible, and we don't expect the changes to impact most apps. In this post, we will guide you through the steps for upgrading libraries to React 19 ...
+
+</BlogCard>
+
<BlogCard title="React Labs: What We've Been Working On – February 2024" date="February 15, 2024" url="/blog/2024/02/15/react-labs-what-we-have-been-working-on-february-2024">
In React Labs posts, we write about projects in active research and development. Since our last update, we've made significant progress on React Compiler, new features, and React 19, and we'd like to share what we learned.
diff --git a/src/content/community/acknowledgements.md b/src/content/community/acknowledgements.md
index c87a92979..760076d83 100644
--- a/src/content/community/acknowledgements.md
+++ b/src/content/community/acknowledgements.md
@@ -4,7 +4,7 @@ title: Acknowledgements
<Intro>
-React was originally created by [Jordan Walke.](https://github.com/jordwalke) Today, React has a [dedicated full-time team working on it](/community/team), as well as over a thousand [open source contributors.](https://github.com/facebook/react/blob/main/AUTHORS)
+React was originally created by [Jordan Walke.](https://github.com/jordwalke) Today, React has a [dedicated full-time team working on it](/community/team), as well as over a thousand [open source contributors.](https://github.com/facebook/react/graphs/contributors)
</Intro>
@@ -16,6 +16,7 @@ We'd like to recognize a few people who have made significant contributions to R
* [Andreas Svensson](https://github.com/syranide)
* [Alex Krolick](https://github.com/alexkrolick)
* [Alexey Pyltsyn](https://github.com/lex111)
+* [Andrey Lunyov](https://github.com/alunyov)
* [Brandon Dail](https://github.com/aweary)
* [Brian Vaughn](https://github.com/bvaughn)
* [Caleb Meredith](https://github.com/calebmer)
@@ -58,7 +59,7 @@ We'd like to recognize a few people who have made significant contributions to R
This list is not exhaustive.
-We'd like to give special thanks to [Tom Occhino](https://github.com/tomocchino) and [Adam Wolff](https://github.com/wolffiex) for their guidance and support over the years. We are also thankful to all the volunteers who [translated React into other languages.](https://translations.reactjs.org/)
+We'd like to give special thanks to [Tom Occhino](https://github.com/tomocchino) and [Adam Wolff](https://github.com/wolffiex) for their guidance and support over the years. We are also thankful to all the volunteers who [translated React into other languages.](https://translations.react.dev/)
## Additional Thanks {/*additional-thanks*/}
diff --git a/src/content/community/conferences.md b/src/content/community/conferences.md
index a28d60848..aaa761218 100644
--- a/src/content/community/conferences.md
+++ b/src/content/community/conferences.md
@@ -10,88 +10,132 @@ Do you know of a local React.js conference? Add it here! (Please keep the list c
## Upcoming Conferences {/*upcoming-conferences*/}
-### React Paris 2024 {/*react-paris-2024*/}
-March 22, 2024. In-person in Paris, France + Remote (hybrid)
+### React Universe Conf 2024 {/*react-universe-conf-2024*/}
+September 5-6, 2024. Wrocław, Poland.
-[Website](https://react.paris/) - [Twitter](https://twitter.com/BeJS_) - [LinkedIn](https://www.linkedin.com/events/7150816372074192900/comments/)
+[Website](https://www.reactuniverseconf.com/) - [Twitter](https://twitter.com/react_native_eu) - [LinkedIn](https://www.linkedin.com/events/reactuniverseconf7163919537074118657/)
-### Epic Web Conf 2024 {/*epic-web-2024*/}
-April 10 - 11, 2024. In-person in Park City, UT, USA
+### React Alicante 2024 {/*react-alicante-2024*/}
+September 19-21, 2024. Alicante, Spain.
-[Website](https://www.epicweb.dev/conf) - [YouTube](https://www.youtube.com/@EpicWebDev)
+[Website](https://reactalicante.es/) - [Twitter](https://twitter.com/ReactAlicante) - [YouTube](https://www.youtube.com/channel/UCaSdUaITU1Cz6PvC97A7e0w)
-### React Miami 2024 {/*react-miami-2024*/}
-April 19 - 20, 2024. In-person in Miami, FL, USA
+### RenderCon Kenya 2024 {/*rendercon-kenya-2024*/}
+October 04 - 05, 2024. Nairobi, Kenya
-[Website](https://reactmiami.com/) - [Twitter](https://twitter.com/ReactMiamiConf)
+[Website](https://rendercon.org/) - [Twitter](https://twitter.com/renderconke) - [LinkedIn](https://www.linkedin.com/company/renderconke/) - [YouTube](https://www.youtube.com/channel/UC0bCcG8gHUL4njDOpQGcMIA)
-### React Connection 2024 {/*react-connection-2024*/}
-April 22, 2024. In-person in Paris, France
+### React India 2024 {/*react-india-2024*/}
+October 17 - 19, 2024. In-person in Goa, India (hybrid event) + Oct 15 2024 - remote day
-[Website](https://reactconnection.io/) - [Twitter](https://twitter.com/ReactConn)
+[Website](https://www.reactindia.io) - [Twitter](https://twitter.com/react_india) - [Facebook](https://www.facebook.com/ReactJSIndia) - [Youtube](https://www.youtube.com/channel/UCaFbHCBkPvVv1bWs_jwYt3w)
-### React Native Connection 2024 {/*react-native-connection-2024*/}
-April 23, 2024. In-person in Paris, France
+### React Brussels 2024 {/*react-brussels-2024*/}
+October 18, 2024. In-person in Brussels, Belgium (hybrid event)
-[Website](https://reactnativeconnection.io/) - [Twitter](https://twitter.com/ReactNativeConn)
+[Website](https://www.react.brussels/) - [Twitter](https://x.com/BrusselsReact)
-### React Conf 2024 {/*react-conf-2024*/}
-May 15 - 16, 2024. In-person in Henderson, NV, USA + remote
+### reactjsday 2024 {/*reactjsday-2024*/}
+October 25, 2024. In-person in Verona, Italy + online (hybrid event)
-[Website](https://conf.react.dev) - [Twitter](https://twitter.com/reactjs)
+[Website](https://2024.reactjsday.it/) - [Twitter](https://x.com/reactjsday) - [Facebook](https://www.facebook.com/GrUSP/) - [YouTube](https://www.youtube.com/c/grusp)
-### App.js Conf 2024 {/*appjs-conf-2024*/}
-May 22 - 24, 2024. In-person in Kraków, Poland + remote
+### React Advanced London 2024 {/*react-advanced-london-2024*/}
+October 25 & 28, 2024. In-person in London, UK + online (hybrid event)
-[Website](https://appjs.co) - [Twitter](https://twitter.com/appjsconf)
+[Website](https://reactadvanced.com/) - [Twitter](https://x.com/reactadvanced)
+
+### React Native London Conf 2024 {/*react-native-london-2024*/}
+November 14 & 15, 2024. In-person in London, UK
+
+[Website](https://reactnativelondon.co.uk/) - [Twitter](https://x.com/RNLConf)
+
+### React Summit US 2024 {/*react-summit-us-2024*/}
+November 19 & 22, 2024. In-person in New York, USA + online (hybrid event)
+
+[Website](https://reactsummit.us/) - [Twitter](https://twitter.com/reactsummit) - [Videos](https://portal.gitnation.org/)
+
+### React Africa 2024 {/*react-africa-2024*/}
+November 29, 2024. In-person in Casablanca, Morocco (hybrid event)
+
+[Website](https://react-africa.com/) - [Twitter](https://x.com/BeJS_)
+
+### React Day Berlin 2024 {/*react-day-berlin-2024*/}
+December 13 & 16, 2024. In-person in Berlin, Germany + remote (hybrid event)
+
+[Website](https://reactday.berlin/) - [Twitter](https://x.com/reactdayberlin)
+
+## Past Conferences {/*past-conferences*/}
+
+### React Rally 2024 🐙 {/*react-rally-2024*/}
+August 12-13, 2024. Park City, UT, USA
+
+[Website](https://reactrally.com) - [Twitter](https://twitter.com/ReactRally) - [YouTube](https://www.youtube.com/channel/UCXBhQ05nu3L1abBUGeQ0ahw)
+
+### The Geek Conf 2024 {/*the-geek-conf-2024*/}
+July 25, 2024. In-person in Berlin, Germany + remote (hybrid event)
+
+[Website](https://thegeekconf.com) - [Twitter](https://twitter.com/thegeekconf)
+
+### Chain React 2024 {/*chain-react-2024*/}
+July 17-19, 2024. In-person in Portland, OR, USA
+
+[Website](https://chainreactconf.com) - [Twitter](https://twitter.com/ChainReactConf)
+
+### React Nexus 2024 {/*react-nexus-2024*/}
+July 04 & 05, 2024. Bangalore, India (In-person event)
+
+[Website](https://reactnexus.com/) - [Twitter](https://twitter.com/ReactNexus) - [Linkedin](https://www.linkedin.com/company/react-nexus) - [YouTube](https://www.youtube.com/reactify_in)
### React Summit 2024 {/*react-summit-2024*/}
June 14 & 18, 2024. In-person in Amsterdam, Netherlands + remote (hybrid event)
[Website](https://reactsummit.com/) - [Twitter](https://twitter.com/reactsummit) - [Videos](https://portal.gitnation.org/)
-### Render(ATL) 2024 🍑 {/*renderatl-2024-*/}
-June 12 - June 14, 2024. Atlanta, GA, USA
-
-[Website](https://renderatl.com) - [Discord](https://www.renderatl.com/discord) - [Twitter](https://twitter.com/renderATL) - [Instagram](https://www.instagram.com/renderatl/) - [Facebook](https://www.facebook.com/renderatl/) - [LinkedIn](https://www.linkedin.com/company/renderatl) - [Podcast](https://www.renderatl.com/culture-and-code#/)
-
### React Norway 2024 {/*react-norway-2024*/}
June 14, 2024. In-person at Farris Bad Hotel in Larvik, Norway and online (hybrid event).
[Website](https://reactnorway.com/) - [Twitter](https://twitter.com/ReactNorway)
-### React Nexus 2024 {/*react-nexus-2024*/}
-July 04 & 05, 2024. Bangalore, India (In-person event)
+### Render(ATL) 2024 🍑 {/*renderatl-2024-*/}
+June 12 - June 14, 2024. Atlanta, GA, USA
-[Website](https://reactnexus.com/) - [Twitter](https://twitter.com/ReactNexus) - [Linkedin](https://www.linkedin.com/company/react-nexus) - [YouTube](https://www.youtube.com/reactify_in)
+[Website](https://renderatl.com) - [Discord](https://www.renderatl.com/discord) - [Twitter](https://twitter.com/renderATL) - [Instagram](https://www.instagram.com/renderatl/) - [Facebook](https://www.facebook.com/renderatl/) - [LinkedIn](https://www.linkedin.com/company/renderatl) - [Podcast](https://www.renderatl.com/culture-and-code#/)
-### Chain React 2024 {/*chain-react-2024*/}
-July 17-19, 2024. In-person in Portland, OR, USA
+### Frontend Nation 2024 {/*frontend-nation-2024*/}
+June 4 - 7, 2024. Online
-[Website](https://chainreactconf.com) - [Twitter](https://twitter.com/ChainReactConf)
+[Website](https://frontendnation.com/) - [Twitter](https://twitter.com/frontendnation)
-### The Geek Conf 2024 {/*the-geek-conf-2024*/}
-July 25, 2024. In-person in Berlin, Germany + remote (hybrid event)
+### App.js Conf 2024 {/*appjs-conf-2024*/}
+May 22 - 24, 2024. In-person in Kraków, Poland + remote
-[Website](https://thegeekconf.com) - [Twitter](https://twitter.com/thegeekconf)
+[Website](https://appjs.co) - [Twitter](https://twitter.com/appjsconf)
-### React Universe Conf 2024 {/*react-universe-conf-2024*/}
-September 5-6, 2024. Wrocław, Poland.
+### React Conf 2024 {/*react-conf-2024*/}
+May 15 - 16, 2024. In-person in Henderson, NV, USA + remote
-[Website](https://www.reactuniverseconf.com/) - [Twitter](https://twitter.com/react_native_eu) - [LinkedIn](https://www.linkedin.com/events/reactuniverseconf7163919537074118657/)
+[Website](https://conf.react.dev) - [Twitter](https://twitter.com/reactjs)
-### React Alicante 2024 {/*react-alicante-2024*/}
-September 19-21, 2024. Alicante, Spain.
+### React Native Connection 2024 {/*react-native-connection-2024*/}
+April 23, 2024. In-person in Paris, France
-[Website](https://reactalicante.es/) - [Twitter](https://twitter.com/ReactAlicante) - [YouTube](https://www.youtube.com/channel/UCaSdUaITU1Cz6PvC97A7e0w)
+[Website](https://reactnativeconnection.io/) - [Twitter](https://twitter.com/ReactNativeConn)
+### React Miami 2024 {/*react-miami-2024*/}
+April 19 - 20, 2024. In-person in Miami, FL, USA
-### React India 2024 {/*react-india-2024*/}
-October 17 - 19, 2024. In-person in Goa, India (hybrid event) + Oct 15 2024 - remote day
+[Website](https://reactmiami.com/) - [Twitter](https://twitter.com/ReactMiamiConf)
-[Website](https://www.reactindia.io) - [Twitter](https://twitter.com/react_india) - [Facebook](https://www.facebook.com/ReactJSIndia) - [Youtube](https://www.youtube.com/channel/UCaFbHCBkPvVv1bWs_jwYt3w)
+### Epic Web Conf 2024 {/*epic-web-2024*/}
+April 10 - 11, 2024. In-person in Park City, UT, USA
-## Past Conferences {/*past-conferences*/}
+[Website](https://www.epicweb.dev/conf) - [YouTube](https://www.youtube.com/@EpicWebDev)
+
+### React Paris 2024 {/*react-paris-2024*/}
+March 22, 2024. In-person in Paris, France + Remote (hybrid)
+
+[Website](https://react.paris/) - [Twitter](https://twitter.com/BeJS_) - [LinkedIn](https://www.linkedin.com/events/7150816372074192900/comments/) - [Videos](https://www.youtube.com/playlist?list=PL53Z0yyYnpWhUzgvr2Nys3kZBBLcY0TA7)
### React Day Berlin 2023 {/*react-day-berlin-2023*/}
December 8 & 12, 2023. In-person in Berlin, Germany + remote first interactivity (hybrid event)
diff --git a/src/content/community/docs-contributors.md b/src/content/community/docs-contributors.md
index cbdbf7d7f..0f9d002d6 100644
--- a/src/content/community/docs-contributors.md
+++ b/src/content/community/docs-contributors.md
@@ -4,7 +4,7 @@ title: Docs Contributors
<Intro>
-React documentation is written and maintained by the [React team](/community/team) and [external contributors.](https://github.com/reactjs/reactjs.org/graphs/contributors) On this page, we'd like to thank a few people who've made significant contributions to this site.
+React documentation is written and maintained by the [React team](/community/team) and [external contributors.](https://github.com/reactjs/react.dev/graphs/contributors) On this page, we'd like to thank a few people who've made significant contributions to this site.
</Intro>
diff --git a/src/content/community/meetups.md b/src/content/community/meetups.md
index a12a5349c..14097aa4d 100644
--- a/src/content/community/meetups.md
+++ b/src/content/community/meetups.md
@@ -30,15 +30,8 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Belo Horizonte](https://www.meetup.com/reactbh/)
* [Curitiba](https://www.meetup.com/pt-br/ReactJS-CWB/)
* [Florianópolis](https://www.meetup.com/pt-br/ReactJS-Floripa/)
-* [Goiânia](https://www.meetup.com/pt-br/React-Goiania/)
* [Joinville](https://www.meetup.com/pt-BR/React-Joinville/)
-* [Juiz de Fora](https://www.meetup.com/pt-br/React-Juiz-de-Fora/)
-* [Maringá](https://www.meetup.com/pt-BR/React-Maringa/)
-* [Porto Alegre](https://www.meetup.com/pt-BR/React-Porto-Alegre/)
-* [Rio de Janeiro](https://www.meetup.com/pt-BR/React-Rio-de-Janeiro/)
-* [Salvador](https://www.meetup.com/pt-BR/ReactSSA)
* [São Paulo](https://www.meetup.com/pt-BR/ReactJS-SP/)
-* [Vila Velha](https://www.meetup.com/pt-BR/React-ES/)
## Bolivia {/*bolivia*/}
* [Bolivia](https://www.meetup.com/ReactBolivia/)
@@ -51,24 +44,13 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Saskatoon, SK](https://www.meetup.com/saskatoon-react-meetup/)
* [Toronto, ON](https://www.meetup.com/Toronto-React-Native/events/)
-## Chile {/*chile*/}
-* [Santiago](https://www.meetup.com/es-ES/react-santiago/)
-
-## China {/*china*/}
-* [Beijing](https://www.meetup.com/Beijing-ReactJS-Meetup/)
-
## Colombia {/*colombia*/}
-* [Bogotá](https://www.meetup.com/meetup-group-iHIeHykY/)
* [Medellin](https://www.meetup.com/React-Medellin/)
-* [Cali](https://www.meetup.com/reactcali/)
## Denmark {/*denmark*/}
* [Aalborg](https://www.meetup.com/Aalborg-React-React-Native-Meetup/)
* [Aarhus](https://www.meetup.com/Aarhus-ReactJS-Meetup/)
-## Egypt {/*egypt*/}
-* [Cairo](https://www.meetup.com/react-cairo/)
-
## England (UK) {/*england-uk*/}
* [Manchester](https://www.meetup.com/Manchester-React-User-Group/)
* [React.JS Girls London](https://www.meetup.com/ReactJS-Girls-London/)
@@ -76,7 +58,6 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [React Native London](https://guild.host/RNLDN)
## France {/*france*/}
-* [Nantes](https://www.meetup.com/React-Nantes/)
* [Lille](https://www.meetup.com/ReactBeerLille/)
* [Paris](https://www.meetup.com/ReactJS-Paris/)
@@ -93,14 +74,11 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Athens](https://www.meetup.com/React-To-React-Athens-MeetUp/)
* [Thessaloniki](https://www.meetup.com/Thessaloniki-ReactJS-Meetup/)
-## Hungary {/*hungary*/}
-* [Budapest](https://www.meetup.com/React-Budapest/)
-
## India {/*india*/}
* [Ahmedabad](https://www.meetup.com/react-ahmedabad/)
* [Bangalore (React)](https://www.meetup.com/ReactJS-Bangalore/)
* [Bangalore (React Native)](https://www.meetup.com/React-Native-Bangalore-Meetup)
-* [Chennai](https://www.meetup.com/React-Chennai/)
+* [Chennai](https://www.linkedin.com/company/chennaireact)
* [Delhi NCR](https://www.meetup.com/React-Delhi-NCR/)
* [Mumbai](https://reactmumbai.dev)
* [Pune](https://www.meetup.com/ReactJS-and-Friends/)
@@ -117,6 +95,9 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
## Italy {/*italy*/}
* [Milan](https://www.meetup.com/React-JS-Milano/)
+## Japan {/*japan*/}
+* [Osaka](https://react-osaka.connpass.com/)
+
## Kenya {/*kenya*/}
* [Nairobi - Reactdevske](https://kommunity.com/reactjs-developer-community-kenya-reactdevske)
@@ -138,12 +119,6 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Karachi](https://www.facebook.com/groups/902678696597634/)
* [Lahore](https://www.facebook.com/groups/ReactjsLahore/)
-## Panama {/*panama*/}
-* [Panama](https://www.meetup.com/React-Panama/)
-
-## Peru {/*peru*/}
-* [Lima](https://www.meetup.com/ReactJS-Peru/)
-
## Philippines {/*philippines*/}
* [Manila](https://www.meetup.com/reactjs-developers-manila/)
* [Manila - ReactJS PH](https://www.meetup.com/ReactJS-Philippines/)
@@ -160,7 +135,6 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
## Spain {/*spain*/}
* [Barcelona](https://www.meetup.com/ReactJS-Barcelona/)
-* [Canarias](https://www.meetup.com/React-Canarias/)
## Sweden {/*sweden*/}
* [Goteborg](https://www.meetup.com/ReactJS-Goteborg/)
@@ -176,7 +150,6 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Kyiv](https://www.meetup.com/Kyiv-ReactJS-Meetup)
## US {/*us*/}
-* [Ann Arbor, MI - ReactJS](https://www.meetup.com/AnnArbor-jsx/)
* [Atlanta, GA - ReactJS](https://www.meetup.com/React-ATL/)
* [Austin, TX - ReactJS](https://www.meetup.com/ReactJS-Austin-Meetup/)
* [Boston, MA - ReactJS](https://www.meetup.com/ReactJS-Boston/)
@@ -187,7 +160,6 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Cleveland, OH - ReactJS](https://www.meetup.com/Cleveland-React/)
* [Columbus, OH - ReactJS](https://www.meetup.com/ReactJS-Columbus-meetup/)
* [Dallas, TX - ReactJS](https://www.meetup.com/ReactDallas/)
-* [Dallas, TX - [Remote] React JS](https://www.meetup.com/React-JS-Group/)
* [Detroit, MI - Detroit React User Group](https://www.meetup.com/Detroit-React-User-Group/)
* [Indianapolis, IN - React.Indy](https://www.meetup.com/React-Indy)
* [Irvine, CA - ReactJS](https://www.meetup.com/ReactJS-OC/)
@@ -197,27 +169,19 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
* [Los Angeles, CA - ReactJS](https://www.meetup.com/socal-react/)
* [Los Angeles, CA - React Native](https://www.meetup.com/React-Native-Los-Angeles/)
* [Miami, FL - ReactJS](https://www.meetup.com/React-Miami/)
-* [Nashville, TN - ReactJS](https://www.meetup.com/NashReact-Meetup/)
* [New York, NY - ReactJS](https://www.meetup.com/NYC-Javascript-React-Group/)
* [New York, NY - React Ladies](https://www.meetup.com/React-Ladies/)
* [New York, NY - React Native](https://www.meetup.com/React-Native-NYC/)
* [New York, NY - useReactNYC](https://www.meetup.com/useReactNYC/)
* [New York, NY - React.NYC](https://guild.host/react-nyc)
-* [Omaha, NE - ReactJS/React Native](https://www.meetup.com/omaha-react-meetup-group/)
* [Palo Alto, CA - React Native](https://www.meetup.com/React-Native-Silicon-Valley/)
-* [Philadelphia, PA - ReactJS](https://www.meetup.com/Reactadelphia/)
* [Phoenix, AZ - ReactJS](https://www.meetup.com/ReactJS-Phoenix/)
-* [Pittsburgh, PA - ReactJS/React Native](https://www.meetup.com/ReactPgh/)
-* [Portland, OR - ReactJS](https://www.meetup.com/Portland-ReactJS/)
* [Provo, UT - ReactJS](https://www.meetup.com/ReactJS-Utah/)
-* [Sacramento, CA - ReactJS](https://www.meetup.com/Sacramento-ReactJS-Meetup/)
* [San Diego, CA - San Diego JS](https://www.meetup.com/sandiegojs/)
* [San Francisco - Real World React](https://www.meetup.com/Real-World-React)
* [San Francisco - ReactJS](https://www.meetup.com/ReactJS-San-Francisco/)
* [San Francisco, CA - React Native](https://www.meetup.com/React-Native-San-Francisco/)
-* [San Ramon, CA - TriValley Coders](https://www.meetup.com/trivalleycoders/)
* [Santa Monica, CA - ReactJS](https://www.meetup.com/Los-Angeles-ReactJS-User-Group/)
-* [Seattle, WA - React Native](https://www.meetup.com/Seattle-React-Native-Meetup/)
* [Seattle, WA - ReactJS](https://www.meetup.com/seattle-react-js/)
* [Tampa, FL - ReactJS](https://www.meetup.com/ReactJS-Tampa-Bay/)
* [Tucson, AZ - ReactJS](https://www.meetup.com/Tucson-ReactJS-Meetup/)
diff --git a/src/content/community/team.md b/src/content/community/team.md
index 9ef95d64a..407448f48 100644
--- a/src/content/community/team.md
+++ b/src/content/community/team.md
@@ -18,11 +18,7 @@ Current members of the React team are listed in alphabetical order below.
Andrew got started with web development by making sites with WordPress, and eventually tricked himself into doing JavaScript. His favorite pastime is karaoke. Andrew is either a Disney villain or a Disney princess, depending on the day.
</TeamMember>
-<TeamMember name="Andrey Lunyov" permalink="andrey-lunyov" photo="/images/team/andrey-lunyov.jpg" github="alunyov" twitter="alunyov" threads="alunyov" title="Engineer at Meta">
- Andrey started his career as a designer and then gradually transitioned into web development. After joining the React Data team at Meta he worked on adding an incremental JavaScript compiler to Relay, and then later on, worked on removing the same compiler from Relay. Outside of work, Andrey likes to play music and engage in various sports.
-</TeamMember>
-
-<TeamMember name="Dan Abramov" permalink="dan-abramov" photo="/images/team/gaearon.jpg" github="gaearon" twitter="dan_abramov" title="Independent Engineer">
+<TeamMember name="Dan Abramov" permalink="dan-abramov" photo="/images/team/gaearon.jpg" github="gaearon" bsky="danabra.mov" title="Independent Engineer">
Dan got into programming after he accidentally discovered Visual Basic inside Microsoft PowerPoint. He has found his true calling in turning [Sebastian](#sebastian-markbåge)'s tweets into long-form blog posts. Dan occasionally wins at Fortnite by hiding in a bush until the game ends.
</TeamMember>
@@ -30,8 +26,12 @@ Current members of the React team are listed in alphabetical order below.
Eli got into programming after he got suspended from middle school for hacking. He has been working on React and React Native since 2017. He enjoys eating treats, especially ice cream and apple pie. You can find Eli trying quirky activities like parkour, indoor skydiving, and aerial silks.
</TeamMember>
+<TeamMember name="Jack Pope" permalink="jack-pope" photo="/images/team/jack-pope.jpg" github="jackpope" personal="jackpope.me" title="Engineer at Meta">
+ Shortly after being introduced to AutoHotkey, Jack had written scripts to automate everything he could think of. When reaching limitations there, he dove headfirst into web app development and hasn't looked back. Most recently, Jack worked on the web platform at Instagram before moving to React. His favorite programming language is JSX.
+</TeamMember>
+
<TeamMember name="Jason Bonta" permalink="jason-bonta" photo="/images/team/jasonbonta.jpg" threads="someextent" title="Engineering Manager at Meta">
- Jason likes having large volumes of Amazon packages delivered to the office so that he can build forts. Despite literally walling himself off from his team at times and not understanding how for-of loops work, we appreciate him for the unique qualities he brings to his work.
+ Jason abandoned embedded C for a career in front-end engineering and never looked back. Armed with esoteric CSS knowledge and a passion for beautiful UI, Jason joined Facebook in 2010, where he now feels privileged to have seen JavaScript development come of age. Though he may not understand how `for...of` loops work, he loves getting to work with brilliant people on projects that enable amazing UX.
</TeamMember>
<TeamMember name="Joe Savona" permalink="joe-savona" photo="/images/team/joe.jpg" github="josephsavona" twitter="en_JS" threads="joesavona" title="Engineer at Meta">
@@ -42,12 +42,12 @@ Current members of the React team are listed in alphabetical order below.
Josh majored in Mathematics and discovered programming while in college. His first professional developer job was to program insurance rate calculations in Microsoft Excel, the paragon of Reactive Programming which must be why he now works on React. In between that time Josh has been an IC, Manager, and Executive at a few startups. outside of work he likes to push his limits with cooking.
</TeamMember>
-<TeamMember name="Lauren Tan" permalink="lauren-tan" photo="/images/team/lauren.jpg" github="poteto" twitter="potetotes" threads="potetotes" personal="no.lol" title="Engineer at Meta">
- Lauren’s programming career peaked when she first discovered the `<marquee>` tag. She’s been chasing that high ever since. When she’s not adding bugs into React, she enjoys dropping cheeky memes in chat, and playing all too many video games with her partner, and her dog Zelda.
+<TeamMember name="Lauren Tan" permalink="lauren-tan" photo="/images/team/lauren.jpg" github="poteto" twitter="potetotes" threads="potetotes" bsky="no.lol" title="Engineer at Meta">
+ Lauren's programming career peaked when she first discovered the `<marquee>` tag. She’s been chasing that high ever since. She studied Finance instead of CS in college, so she learned to code using Excel instead of Java. Lauren enjoys dropping cheeky memes in chat, playing video games with her partner, and petting her dog Zelda.
</TeamMember>
<TeamMember name="Luna Wei" permalink="luna-wei" photo="/images/team/luna-wei.jpg" github="lunaleaps" twitter="lunaleaps" threads="lunaleaps" title="Engineer at Meta">
- Luna first learnt the fundamentals of python at the age of 6 from her father. Since then, she has been unstoppable. Luna aspires to be a gen z, and the road to success is paved with environmental advocacy, urban gardening and lots of quality time with her Voo-Doo’d (as pictured).
+ Luna first learnt the fundamentals of python at the age of 6 from her father. Since then, she has been unstoppable. Luna aspires to be a gen z, and the road to success is paved with environmental advocacy, urban gardening and lots of quality time with her Voo-Doo’d (as pictured).
</TeamMember>
<TeamMember name="Matt Carroll" permalink="matt-carroll" photo="/images/team/matt-carroll.png" github="mattcarrollcode" twitter="mattcarrollcode" threads="mattcarrollcode" title="Developer Advocate at Meta">
@@ -62,10 +62,14 @@ Current members of the React team are listed in alphabetical order below.
Noah’s interest in UI programming sparked during his education in music technology at NYU. At Meta, he's worked on internal tools, browsers, web performance, and is currently focused on React. Outside of work, Noah can be found tinkering with synthesizers or spending time with his cat.
</TeamMember>
-<TeamMember name="Rick Hanlon" permalink="rick-hanlon" photo="/images/team/rickhanlonii.jpg" github="rickhanlonii" twitter="rickhanlonii" threads="rickhanlonii" personal="rickhanlon.codes" title="Engineer at Meta">
+<TeamMember name="Rick Hanlon" permalink="rick-hanlon" photo="/images/team/rickhanlonii.jpg" github="rickhanlonii" twitter="rickhanlonii" threads="rickhanlonii" bsky="ricky.fm" title="Engineer at Meta">
Ricky majored in theoretical math and somehow found himself on the React Native team for a couple years before joining the React team. When he's not programming you can find him snowboarding, biking, climbing, golfing, or closing GitHub issues that do not match the issue template.
</TeamMember>
+<TeamMember name="Ruslan Lesiutin" permalink="ruslan-lesiutin" photo="/images/team/lesiutin.jpg" github="hoxyq" twitter="ruslanlesiutin" threads="lesiutin" title="Engineer at Meta">
+ Ruslan's introduction to UI programming started when he was a kid by manually editing HTML templates for his custom gaming forums. Somehow, he ended up majoring in Computer Science. He enjoys music, games, and memes. Mostly memes.
+</TeamMember>
+
<TeamMember name="Sathya Gunasekaran " permalink="sathya-gunasekaran" photo="/images/team/sathya.jpg" github="gsathya" twitter="_gsathya" threads="gsathya.03" title="Engineer at Meta">
Sathya hated the Dragon Book in school but somehow ended up working on compilers all his career. When he's not compiling React components, he's either drinking coffee or eating yet another Dosa.
</TeamMember>
@@ -74,7 +78,7 @@ Current members of the React team are listed in alphabetical order below.
Sebastian majored in psychology. He's usually quiet. Even when he says something, it often doesn't make sense to the rest of us until a few months later. The correct way to pronounce his surname is "mark-boa-geh" but he settled for "mark-beige" out of pragmatism -- and that's how he approaches React.
</TeamMember>
-<TeamMember name="Sebastian Silbermann" permalink="sebastian-silbermann" photo="/images/team/sebsilbermann.jpg" github="eps1lon" twitter="sebsilbermann" threads="sebsilbermann" title="Independent Engineer">
+<TeamMember name="Sebastian Silbermann" permalink="sebastian-silbermann" photo="/images/team/sebsilbermann.jpg" github="eps1lon" twitter="sebsilbermann" threads="sebsilbermann" title="Engineer at Vercel">
Sebastian learned programming to make the browser games he played during class more enjoyable. Eventually this lead to contributing to as much open source code as possible. Outside of coding he's busy making sure people don't confuse him with the other Sebastians and Zilberman of the React community.
</TeamMember>
diff --git a/src/content/community/translations.md b/src/content/community/translations.md
new file mode 100644
index 000000000..4c07e6a1e
--- /dev/null
+++ b/src/content/community/translations.md
@@ -0,0 +1,35 @@
+---
+title: Translations
+---
+
+<Intro>
+
+React docs are translated by the global community into many languages all over the world.
+
+</Intro>
+
+## Source site {/*main-site*/}
+
+All translations are provided from the canonical source docs:
+
+- [English](https://react.dev/) — [Contribute](https://github.com/reactjs/react.dev/)
+
+## Full translations {/*full-translations*/}
+
+{/* If you are a language maintainer and want to add your language here, finish the "Core" translations and edit `deployedTranslations` under `src/utils`. */}
+
+<LanguageList progress="complete" />
+
+## In-progress translations {/*in-progress-translations*/}
+
+For the progress of each translation, see: [Is React Translated Yet?](https://translations.react.dev/)
+
+<LanguageList progress="in-progress" />
+
+## How to contribute {/*how-to-contribute*/}
+
+You can contribute to the translation efforts!
+
+The community conducts the translation work for the React docs on each language-specific fork of react.dev. Typical translation work involves directly translating a Markdown file and creating a pull request. Click the "contribute" link above to the GitHub repository for your language, and follow the instructions there to help with the translation effort.
+
+If you want to start a new translation for your language, visit: [translations.react.dev](https://github.com/reactjs/translations.react.dev)
\ No newline at end of file
diff --git a/src/content/community/versioning-policy.md b/src/content/community/versioning-policy.md
index fad926c57..7aa71efd2 100644
--- a/src/content/community/versioning-policy.md
+++ b/src/content/community/versioning-policy.md
@@ -8,6 +8,8 @@ All stable builds of React go through a high level of testing and follow semanti
</Intro>
+For a list of previous releases, see the [Versions](/versions) page.
+
## Stable releases {/*stable-releases*/}
Stable React releases (also known as "Latest" release channel) follow [semantic versioning (semver)](https://semver.org/) principles.
diff --git a/src/content/learn/adding-interactivity.md b/src/content/learn/adding-interactivity.md
index 0d4a3b23f..5c87a3e79 100644
--- a/src/content/learn/adding-interactivity.md
+++ b/src/content/learn/adding-interactivity.md
@@ -265,7 +265,7 @@ setCount(count + 1); // Request a re-render with 1
console.log(count); // Still 0!
```
-This behavior help you avoid subtle bugs. Here is a little chat app. Try to guess what happens if you press "Send" first and *then* change the recipient to Bob. Whose name will appear in the `alert` five seconds later?
+This behavior helps you avoid subtle bugs. Here is a little chat app. Try to guess what happens if you press "Send" first and *then* change the recipient to Bob. Whose name will appear in the `alert` five seconds later?
<Sandpack>
diff --git a/src/content/learn/conditional-rendering.md b/src/content/learn/conditional-rendering.md
index 895d610d3..95be5d2e0 100644
--- a/src/content/learn/conditional-rendering.md
+++ b/src/content/learn/conditional-rendering.md
@@ -52,13 +52,13 @@ export default function PackingList() {
</Sandpack>
-Notice that some of the `Item` components have their `isPacked` prop set to `true` instead of `false`. You want to add a checkmark (✔) to packed items if `isPacked={true}`.
+Notice that some of the `Item` components have their `isPacked` prop set to `true` instead of `false`. You want to add a checkmark (✅) to packed items if `isPacked={true}`.
You can write this as an [`if`/`else` statement](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if...else) like so:
```js
if (isPacked) {
- return <li className="item">{name} ✔</li>;
+ return <li className="item">{name} ✅</li>;
}
return <li className="item">{name}</li>;
```
@@ -70,7 +70,7 @@ If the `isPacked` prop is `true`, this code **returns a different JSX tree.** Wi
```js
function Item({ name, isPacked }) {
if (isPacked) {
- return <li className="item">{name} ✔</li>;
+ return <li className="item">{name} ✅</li>;
}
return <li className="item">{name}</li>;
}
@@ -159,7 +159,7 @@ In practice, returning `null` from a component isn't common because it might sur
In the previous example, you controlled which (if any!) JSX tree would be returned by the component. You may already have noticed some duplication in the render output:
```js
-<li className="item">{name} ✔</li>
+<li className="item">{name} ✅</li>
```
is very similar to
@@ -172,7 +172,7 @@ Both of the conditional branches return `<li className="item">...</li>`:
```js
if (isPacked) {
- return <li className="item">{name} ✔</li>;
+ return <li className="item">{name} ✅</li>;
}
return <li className="item">{name}</li>;
```
@@ -187,7 +187,7 @@ Instead of this:
```js
if (isPacked) {
- return <li className="item">{name} ✔</li>;
+ return <li className="item">{name} ✅</li>;
}
return <li className="item">{name}</li>;
```
@@ -197,12 +197,12 @@ You can write this:
```js
return (
<li className="item">
- {isPacked ? name + ' ✔' : name}
+ {isPacked ? name + ' ✅' : name}
</li>
);
```
-You can read it as *"if `isPacked` is true, then (`?`) render `name + ' ✔'`, otherwise (`:`) render `name`"*.
+You can read it as *"if `isPacked` is true, then (`?`) render `name + ' ✅'`, otherwise (`:`) render `name`"*.
<DeepDive>
@@ -222,7 +222,7 @@ function Item({ name, isPacked }) {
<li className="item">
{isPacked ? (
<del>
- {name + ' ✔'}
+ {name + ' ✅'}
</del>
) : (
name
@@ -265,7 +265,7 @@ Another common shortcut you'll encounter is the [JavaScript logical AND (`&&`) o
```js
return (
<li className="item">
- {name} {isPacked && '✔'}
+ {name} {isPacked && '✅'}
</li>
);
```
@@ -280,7 +280,7 @@ Here it is in action:
function Item({ name, isPacked }) {
return (
<li className="item">
- {name} {isPacked && '✔'}
+ {name} {isPacked && '✅'}
</li>
);
}
@@ -337,7 +337,7 @@ Use an `if` statement to reassign a JSX expression to `itemContent` if `isPacked
```js
if (isPacked) {
- itemContent = name + " ✔";
+ itemContent = name + " ✅";
}
```
@@ -357,7 +357,7 @@ This style is the most verbose, but it's also the most flexible. Here it is in a
function Item({ name, isPacked }) {
let itemContent = name;
if (isPacked) {
- itemContent = name + " ✔";
+ itemContent = name + " ✅";
}
return (
<li className="item">
@@ -401,7 +401,7 @@ function Item({ name, isPacked }) {
if (isPacked) {
itemContent = (
<del>
- {name + " ✔"}
+ {name + " ✅"}
</del>
);
}
@@ -464,7 +464,7 @@ Use the conditional operator (`cond ? a : b`) to render a ❌ if `isPacked` isn
function Item({ name, isPacked }) {
return (
<li className="item">
- {name} {isPacked && '✔'}
+ {name} {isPacked && '✅'}
</li>
);
}
@@ -502,7 +502,7 @@ export default function PackingList() {
function Item({ name, isPacked }) {
return (
<li className="item">
- {name} {isPacked ? '✔' : '❌'}
+ {name} {isPacked ? '✅' : '❌'}
</li>
);
}
diff --git a/src/content/learn/describing-the-ui.md b/src/content/learn/describing-the-ui.md
index ce49b85c8..34ee0c01a 100644
--- a/src/content/learn/describing-the-ui.md
+++ b/src/content/learn/describing-the-ui.md
@@ -327,7 +327,7 @@ In this example, the JavaScript `&&` operator is used to conditionally render a
function Item({ name, isPacked }) {
return (
<li className="item">
- {name} {isPacked && '✔'}
+ {name} {isPacked && '✅'}
</li>
);
}
diff --git a/src/content/learn/editor-setup.md b/src/content/learn/editor-setup.md
index 0a12fa5b4..11fdf369c 100644
--- a/src/content/learn/editor-setup.md
+++ b/src/content/learn/editor-setup.md
@@ -40,7 +40,11 @@ title: התקנת עורך קוד
### Formatting {/*formatting*/}
+<<<<<<< HEAD
הדרך האחרון שאתה רוצה כשאתה משתף קוד עם מפתח אחר הוא להיכנס לוויכוח [tabs vs spaces](https://www.google.com/search?q=tabs+vs+spaces). למזלנו, [prettier](https://prettier.io/)) ינקה את הקוד שלך על ידי התאמתו לחוקים קיימים. בעת הרצת prettier, כל ה-tabs יהפכו ל-spaces, וגרשיים כפולים או יחידים ישונו בהתאם לקונפיגורציה. בסביבת פיתוח אידיאלית, Prettier ירוץ בעת שמירת קובץ, ויעשה את כל השינויים הללו אוטומטית.
+=======
+The last thing you want to do when sharing your code with another contributor is get into a discussion about [tabs vs spaces](https://www.google.com/search?q=tabs+vs+spaces)! Fortunately, [Prettier](https://prettier.io/) will clean up your code by reformatting it to conform to preset, configurable rules. Run Prettier, and all your tabs will be converted to spaces—and your indentation, quotes, etc will also all be changed to conform to the configuration. In the ideal setup, Prettier will run when you save your file, quickly making these edits for you.
+>>>>>>> 8201e7e9203321bd1648c3ab0b76ef943c9ec3ad
ניתן להתקין את Prettier ב[VS Code](https://marketplace.visualstudio.com/items?itemName=esbenp.prettier-vscode) בעזרת הצעדים הבאים:
diff --git a/src/content/learn/installation.md b/src/content/learn/installation.md
index c5426ea94..7251fc31b 100644
--- a/src/content/learn/installation.md
+++ b/src/content/learn/installation.md
@@ -37,7 +37,7 @@ export default function App() {
You can edit it directly or open it in a new tab by pressing the "Fork" button in the upper right corner.
-Most pages in the React documentation contain sandboxes like this. Outside of the React documentation, there are many online sandboxes that support React: for example, [CodeSandbox](https://codesandbox.io/s/new), [StackBlitz](https://stackblitz.com/fork/react), or [CodePen.](https://codepen.io/pen?&editors=0010&layout=left&prefill_data_id=3f4569d1-1b11-4bce-bd46-89090eed5ddb)
+Most pages in the React documentation contain sandboxes like this. Outside of the React documentation, there are many online sandboxes that support React: for example, [CodeSandbox](https://codesandbox.io/s/new), [StackBlitz](https://stackblitz.com/fork/react), or [CodePen.](https://codepen.io/pen?template=QWYVwWN)
### Try React locally {/*try-react-locally*/}
diff --git a/src/content/learn/manipulating-the-dom-with-refs.md b/src/content/learn/manipulating-the-dom-with-refs.md
index 3d5cbfd1d..e881c8a1f 100644
--- a/src/content/learn/manipulating-the-dom-with-refs.md
+++ b/src/content/learn/manipulating-the-dom-with-refs.md
@@ -124,35 +124,35 @@ export default function CatFriends() {
<>
<nav>
<button onClick={handleScrollToFirstCat}>
- Tom
+ Neo
</button>
<button onClick={handleScrollToSecondCat}>
- Maru
+ Millie
</button>
<button onClick={handleScrollToThirdCat}>
- Jellylorum
+ Bella
</button>
</nav>
<div>
<ul>
<li>
<img
- src="https://placekitten.com/g/200/200"
- alt="Tom"
+ src="https://placecats.com/neo/300/200"
+ alt="Neo"
ref={firstCatRef}
/>
</li>
<li>
<img
- src="https://placekitten.com/g/300/200"
- alt="Maru"
+ src="https://placecats.com/millie/200/200"
+ alt="Millie"
ref={secondCatRef}
/>
</li>
<li>
<img
- src="https://placekitten.com/g/250/200"
- alt="Jellylorum"
+ src="https://placecats.com/bella/199/200"
+ alt="Bella"
ref={thirdCatRef}
/>
</li>
@@ -218,18 +218,19 @@ This example shows how you can use this approach to scroll to an arbitrary node
<Sandpack>
```js
-import { useRef } from 'react';
+import { useRef, useState } from "react";
export default function CatFriends() {
const itemsRef = useRef(null);
+ const [catList, setCatList] = useState(setupCatList);
- function scrollToId(itemId) {
+ function scrollToCat(cat) {
const map = getMap();
- const node = map.get(itemId);
+ const node = map.get(cat);
node.scrollIntoView({
- behavior: 'smooth',
- block: 'nearest',
- inline: 'center'
+ behavior: "smooth",
+ block: "nearest",
+ inline: "center",
});
}
@@ -244,34 +245,25 @@ export default function CatFriends() {
return (
<>
<nav>
- <button onClick={() => scrollToId(0)}>
- Tom
- </button>
- <button onClick={() => scrollToId(5)}>
- Maru
- </button>
- <button onClick={() => scrollToId(9)}>
- Jellylorum
- </button>
+ <button onClick={() => scrollToCat(catList[0])}>Neo</button>
+ <button onClick={() => scrollToCat(catList[5])}>Millie</button>
+ <button onClick={() => scrollToCat(catList[9])}>Bella</button>
</nav>
<div>
<ul>
- {catList.map(cat => (
+ {catList.map((cat) => (
<li
- key={cat.id}
+ key={cat}
ref={(node) => {
const map = getMap();
if (node) {
- map.set(cat.id, node);
+ map.set(cat, node);
} else {
- map.delete(cat.id);
+ map.delete(cat);
}
}}
>
- <img
- src={cat.imageUrl}
- alt={'Cat #' + cat.id}
- />
+ <img src={cat} />
</li>
))}
</ul>
@@ -280,12 +272,13 @@ export default function CatFriends() {
);
}
-const catList = [];
-for (let i = 0; i < 10; i++) {
- catList.push({
- id: i,
- imageUrl: 'https://placekitten.com/250/200?image=' + i
- });
+function setupCatList() {
+ const catList = [];
+ for (let i = 0; i < 10; i++) {
+ catList.push("https://loremflickr.com/320/240/cat?lock=" + i);
+ }
+
+ return catList;
}
```
@@ -316,6 +309,16 @@ li {
}
```
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "canary",
+ "react-dom": "canary",
+ "react-scripts": "^5.0.0"
+ }
+}
+```
+
</Sandpack>
In this example, `itemsRef` doesn't hold a single DOM node. Instead, it holds a [Map](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Map) from item ID to a DOM node. ([Refs can hold any values!](/learn/referencing-values-with-refs)) The [`ref` callback](/reference/react-dom/components/common#ref-callback) on every list item takes care to update the Map:
@@ -327,10 +330,10 @@ In this example, `itemsRef` doesn't hold a single DOM node. Instead, it holds a
const map = getMap();
if (node) {
// Add to the Map
- map.set(cat.id, node);
+ map.set(cat, node);
} else {
// Remove from the Map
- map.delete(cat.id);
+ map.delete(cat);
}
}}
>
@@ -338,6 +341,28 @@ In this example, `itemsRef` doesn't hold a single DOM node. Instead, it holds a
This lets you read individual DOM nodes from the Map later.
+<Canary>
+
+This example shows another approach for managing the Map with a `ref` callback cleanup function.
+
+```js
+<li
+ key={cat.id}
+ ref={node => {
+ const map = getMap();
+ // Add to the Map
+ map.set(cat, node);
+
+ return () => {
+ // Remove from the Map
+ map.delete(cat);
+ };
+ }}
+>
+```
+
+</Canary>
+
</DeepDive>
## Accessing another component's DOM nodes {/*accessing-another-components-dom-nodes*/}
@@ -493,7 +518,7 @@ In general, you [don't want](/learn/referencing-values-with-refs#best-practices-
React sets `ref.current` during the commit. Before updating the DOM, React sets the affected `ref.current` values to `null`. After updating the DOM, React immediately sets them to the corresponding DOM nodes.
-**Usually, you will access refs from event handlers.** If you want to do something with a ref, but there is no particular event to do it in, you might need an Effect. We will discuss effects on the next pages.
+**Usually, you will access refs from event handlers.** If you want to do something with a ref, but there is no particular event to do it in, you might need an Effect. We will discuss Effects on the next pages.
<DeepDive>
@@ -923,7 +948,7 @@ const catList = [];
for (let i = 0; i < 10; i++) {
catList.push({
id: i,
- imageUrl: 'https://placekitten.com/250/200?image=' + i
+ imageUrl: 'https://loremflickr.com/250/200/cat?lock=' + i
});
}
@@ -1040,7 +1065,7 @@ const catList = [];
for (let i = 0; i < 10; i++) {
catList.push({
id: i,
- imageUrl: 'https://placekitten.com/250/200?image=' + i
+ imageUrl: 'https://loremflickr.com/250/200/cat?lock=' + i
});
}
diff --git a/src/content/learn/react-compiler.md b/src/content/learn/react-compiler.md
new file mode 100644
index 000000000..df46954d2
--- /dev/null
+++ b/src/content/learn/react-compiler.md
@@ -0,0 +1,378 @@
+---
+title: React Compiler
+---
+
+<Intro>
+This page will give you an introduction to React Compiler and how to try it out successfully.
+</Intro>
+
+<Wip>
+These docs are still a work in progress. More documentation is available in the [React Compiler Working Group repo](https://github.com/reactwg/react-compiler/discussions), and will be upstreamed into these docs when they are more stable.
+</Wip>
+
+<YouWillLearn>
+
+* Getting started with the compiler
+* Installing the compiler and ESLint plugin
+* Troubleshooting
+
+</YouWillLearn>
+
+<Note>
+React Compiler is a new compiler currently in Beta, that we've open sourced to get early feedback from the community. While it has been used in production at companies like Meta, rolling out the compiler to production for your app will depend on the health of your codebase and how well you’ve followed the [Rules of React](/reference/rules).
+
+The latest Beta release can be found with the `@beta` tag, and daily experimental releases with `@experimental`.
+</Note>
+
+React Compiler is a new compiler that we've open sourced to get early feedback from the community. It is a build-time only tool that automatically optimizes your React app. It works with plain JavaScript, and understands the [Rules of React](/reference/rules), so you don't need to rewrite any code to use it.
+
+The compiler also includes an [ESLint plugin](#installing-eslint-plugin-react-compiler) that surfaces the analysis from the compiler right in your editor. **We strongly recommend everyone use the linter today.** The linter does not require that you have the compiler installed, so you can use it even if you are not ready to try out the compiler.
+
+The compiler is currently released as `beta`, and is available to try out on React 17+ apps and libraries. To install the Beta:
+
+<TerminalBlock>
+npm install -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+Or, if you're using Yarn:
+
+<TerminalBlock>
+yarn add -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+If you are not using React 19 yet, please see [the section below](#using-react-compiler-with-react-17-or-18) for further instructions.
+
+### What does the compiler do? {/*what-does-the-compiler-do*/}
+
+In order to optimize applications, React Compiler automatically memoizes your code. You may be familiar today with memoization through APIs such as `useMemo`, `useCallback`, and `React.memo`. With these APIs you can tell React that certain parts of your application don't need to recompute if their inputs haven't changed, reducing work on updates. While powerful, it's easy to forget to apply memoization or apply them incorrectly. This can lead to inefficient updates as React has to check parts of your UI that don't have any _meaningful_ changes.
+
+The compiler uses its knowledge of JavaScript and React's rules to automatically memoize values or groups of values within your components and hooks. If it detects breakages of the rules, it will automatically skip over just those components or hooks, and continue safely compiling other code.
+
+<Note>
+React Compiler can statically detect when Rules of React are broken, and safely opt-out of optimizing just the affected components or hooks. It is not necessary for the compiler to optimize 100% of your codebase.
+</Note>
+
+If your codebase is already very well-memoized, you might not expect to see major performance improvements with the compiler. However, in practice memoizing the correct dependencies that cause performance issues is tricky to get right by hand.
+
+<DeepDive>
+#### What kind of memoization does React Compiler add? {/*what-kind-of-memoization-does-react-compiler-add*/}
+
+The initial release of React Compiler is primarily focused on **improving update performance** (re-rendering existing components), so it focuses on these two use cases:
+
+1. **Skipping cascading re-rendering of components**
+ * Re-rendering `<Parent />` causes many components in its component tree to re-render, even though only `<Parent />` has changed
+1. **Skipping expensive calculations from outside of React**
+ * For example, calling `expensivelyProcessAReallyLargeArrayOfObjects()` inside of your component or hook that needs that data
+
+#### Optimizing Re-renders {/*optimizing-re-renders*/}
+
+React lets you express your UI as a function of their current state (more concretely: their props, state, and context). In its current implementation, when a component's state changes, React will re-render that component _and all of its children_ — unless you have applied some form of manual memoization with `useMemo()`, `useCallback()`, or `React.memo()`. For example, in the following example, `<MessageButton>` will re-render whenever `<FriendList>`'s state changes:
+
+```javascript
+function FriendList({ friends }) {
+ const onlineCount = useFriendOnlineCount();
+ if (friends.length === 0) {
+ return <NoFriends />;
+ }
+ return (
+ <div>
+ <span>{onlineCount} online</span>
+ {friends.map((friend) => (
+ <FriendListCard key={friend.id} friend={friend} />
+ ))}
+ <MessageButton />
+ </div>
+ );
+}
+```
+[_See this example in the React Compiler Playground_](https://playground.react.dev/#N4Igzg9grgTgxgUxALhAMygOzgFwJYSYAEAYjHgpgCYAyeYOAFMEWuZVWEQL4CURwADrEicQgyKEANnkwIAwtEw4iAXiJQwCMhWoB5TDLmKsTXgG5hRInjRFGbXZwB0UygHMcACzWr1ABn4hEWsYBBxYYgAeADkIHQ4uAHoAPksRbisiMIiYYkYs6yiqPAA3FMLrIiiwAAcAQ0wU4GlZBSUcbklDNqikusaKkKrgR0TnAFt62sYHdmp+VRT7SqrqhOo6Bnl6mCoiAGsEAE9VUfmqZzwqLrHqM7ubolTVol5eTOGigFkEMDB6u4EAAhKA4HCEZ5DNZ9ErlLIWYTcEDcIA)
+
+React Compiler automatically applies the equivalent of manual memoization, ensuring that only the relevant parts of an app re-render as state changes, which is sometimes referred to as "fine-grained reactivity". In the above example, React Compiler determines that the return value of `<FriendListCard />` can be reused even as `friends` changes, and can avoid recreating this JSX _and_ avoid re-rendering `<MessageButton>` as the count changes.
+
+#### Expensive calculations also get memoized {/*expensive-calculations-also-get-memoized*/}
+
+The compiler can also automatically memoize for expensive calculations used during rendering:
+
+```js
+// **Not** memoized by React Compiler, since this is not a component or hook
+function expensivelyProcessAReallyLargeArrayOfObjects() { /* ... */ }
+
+// Memoized by React Compiler since this is a component
+function TableContainer({ items }) {
+ // This function call would be memoized:
+ const data = expensivelyProcessAReallyLargeArrayOfObjects(items);
+ // ...
+}
+```
+[_See this example in the React Compiler Playground_](https://playground.react.dev/#N4Igzg9grgTgxgUxALhAejQAgFTYHIQAuumAtgqRAJYBeCAJpgEYCemASggIZyGYDCEUgAcqAGwQwANJjBUAdokyEAFlTCZ1meUUxdMcIcIjyE8vhBiYVECAGsAOvIBmURYSonMCAB7CzcgBuCGIsAAowEIhgYACCnFxioQAyXDAA5gixMDBcLADyzvlMAFYIvGAAFACUmMCYaNiYAHStOFgAvk5OGJgAshTUdIysHNy8AkbikrIKSqpaWvqGIiZmhE6u7p7ymAAqXEwSguZcCpKV9VSEFBodtcBOmAYmYHz0XIT6ALzefgFUYKhCJRBAxeLcJIsVIZLI5PKFYplCqVa63aoAbm6u0wMAQhFguwAPPRAQA+YAfL4dIloUmBMlODogDpAA)
+
+However, if `expensivelyProcessAReallyLargeArrayOfObjects` is truly an expensive function, you may want to consider implementing its own memoization outside of React, because:
+
+- React Compiler only memoizes React components and hooks, not every function
+- React Compiler's memoization is not shared across multiple components or hooks
+
+So if `expensivelyProcessAReallyLargeArrayOfObjects` was used in many different components, even if the same exact items were passed down, that expensive calculation would be run repeatedly. We recommend [profiling](https://react.dev/reference/react/useMemo#how-to-tell-if-a-calculation-is-expensive) first to see if it really is that expensive before making code more complicated.
+</DeepDive>
+
+### Should I try out the compiler? {/*should-i-try-out-the-compiler*/}
+
+Please note that the compiler is still in Beta and has many rough edges. While it has been used in production at companies like Meta, rolling out the compiler to production for your app will depend on the health of your codebase and how well you've followed the [Rules of React](/reference/rules).
+
+**You don't have to rush into using the compiler now. It's okay to wait until it reaches a stable release before adopting it.** However, we do appreciate trying it out in small experiments in your apps so that you can [provide feedback](#reporting-issues) to us to help make the compiler better.
+
+## Getting Started {/*getting-started*/}
+
+In addition to these docs, we recommend checking the [React Compiler Working Group](https://github.com/reactwg/react-compiler) for additional information and discussion about the compiler.
+
+### Installing eslint-plugin-react-compiler {/*installing-eslint-plugin-react-compiler*/}
+
+React Compiler also powers an ESLint plugin. The ESLint plugin can be used **independently** of the compiler, meaning you can use the ESLint plugin even if you don't use the compiler.
+
+<TerminalBlock>
+npm install -D eslint-plugin-react-compiler@beta
+</TerminalBlock>
+
+Then, add it to your ESLint config:
+
+```js
+import reactCompiler from 'eslint-plugin-react-compiler'
+
+export default [
+ {
+ plugins: {
+ 'react-compiler': reactCompiler,
+ },
+ rules: {
+ 'react-compiler/react-compiler': 'error',
+ },
+ },
+]
+```
+
+Or, in the deprecated eslintrc config format:
+
+```js
+module.exports = {
+ plugins: [
+ 'eslint-plugin-react-compiler',
+ ],
+ rules: {
+ 'react-compiler/react-compiler': 'error',
+ },
+}
+```
+
+The ESLint plugin will display any violations of the rules of React in your editor. When it does this, it means that the compiler has skipped over optimizing that component or hook. This is perfectly okay, and the compiler can recover and continue optimizing other components in your codebase.
+
+<Note>
+**You don't have to fix all ESLint violations straight away.** You can address them at your own pace to increase the amount of components and hooks being optimized, but it is not required to fix everything before you can use the compiler.
+</Note>
+
+### Rolling out the compiler to your codebase {/*using-the-compiler-effectively*/}
+
+#### Existing projects {/*existing-projects*/}
+The compiler is designed to compile functional components and hooks that follow the [Rules of React](/reference/rules). It can also handle code that breaks those rules by bailing out (skipping over) those components or hooks. However, due to the flexible nature of JavaScript, the compiler cannot catch every possible violation and may compile with false negatives: that is, the compiler may accidentally compile a component/hook that breaks the Rules of React which can lead to undefined behavior.
+
+For this reason, to adopt the compiler successfully on existing projects, we recommend running it on a small directory in your product code first. You can do this by configuring the compiler to only run on a specific set of directories:
+
+```js {3}
+const ReactCompilerConfig = {
+ sources: (filename) => {
+ return filename.indexOf('src/path/to/dir') !== -1;
+ },
+};
+```
+
+When you have more confidence with rolling out the compiler, you can expand coverage to other directories as well and slowly roll it out to your whole app.
+
+#### New projects {/*new-projects*/}
+
+If you're starting a new project, you can enable the compiler on your entire codebase, which is the default behavior.
+
+### Using React Compiler with React 17 or 18 {/*using-react-compiler-with-react-17-or-18*/}
+
+React Compiler works best with React 19 RC. If you are unable to upgrade, you can install the extra `react-compiler-runtime` package which will allow the compiled code to run on versions prior to 19. However, note that the minimum supported version is 17.
+
+<TerminalBlock>
+npm install react-compiler-runtime@beta
+</TerminalBlock>
+
+You should also add the correct `target` to your compiler config, where `target` is the major version of React you are targeting:
+
+```js {3}
+// babel.config.js
+const ReactCompilerConfig = {
+ target: '18' // '17' | '18' | '19'
+};
+
+module.exports = function () {
+ return {
+ plugins: [
+ ['babel-plugin-react-compiler', ReactCompilerConfig],
+ ],
+ };
+};
+```
+
+### Using the compiler on libraries {/*using-the-compiler-on-libraries*/}
+
+React Compiler can also be used to compile libraries. Because React Compiler needs to run on the original source code prior to any code transformations, it is not possible for an application's build pipeline to compile the libraries they use. Hence, our recommendation is for library maintainers to independently compile and test their libraries with the compiler, and ship compiled code to npm.
+
+Because your code is pre-compiled, users of your library will not need to have the compiler enabled in order to benefit from the automatic memoization applied to your library. If your library targets apps not yet on React 19, specify a minimum [`target` and add `react-compiler-runtime` as a direct dependency](#using-react-compiler-with-react-17-or-18). The runtime package will use the correct implementation of APIs depending on the application's version, and polyfill the missing APIs if necessary.
+
+Library code can often require more complex patterns and usage of escape hatches. For this reason, we recommend ensuring that you have sufficient testing in order to identify any issues that might arise from using the compiler on your library. If you identify any issues, you can always opt-out the specific components or hooks with the [`'use no memo'` directive](#something-is-not-working-after-compilation).
+
+Similarly to apps, it is not necessary to fully compile 100% of your components or hooks to see benefits in your library. A good starting point might be to identify the most performance sensitive parts of your library and ensuring that they don't break the [Rules of React](/reference/rules), which you can use `eslint-plugin-react-compiler` to identify.
+
+## Usage {/*installation*/}
+
+### Babel {/*usage-with-babel*/}
+
+<TerminalBlock>
+npm install babel-plugin-react-compiler@beta
+</TerminalBlock>
+
+The compiler includes a Babel plugin which you can use in your build pipeline to run the compiler.
+
+After installing, add it to your Babel config. Please note that it's critical that the compiler run **first** in the pipeline:
+
+```js {7}
+// babel.config.js
+const ReactCompilerConfig = { /* ... */ };
+
+module.exports = function () {
+ return {
+ plugins: [
+ ['babel-plugin-react-compiler', ReactCompilerConfig], // must run first!
+ // ...
+ ],
+ };
+};
+```
+
+`babel-plugin-react-compiler` should run first before other Babel plugins as the compiler requires the input source information for sound analysis.
+
+### Vite {/*usage-with-vite*/}
+
+If you use Vite, you can add the plugin to vite-plugin-react:
+
+```js {10}
+// vite.config.js
+const ReactCompilerConfig = { /* ... */ };
+
+export default defineConfig(() => {
+ return {
+ plugins: [
+ react({
+ babel: {
+ plugins: [
+ ["babel-plugin-react-compiler", ReactCompilerConfig],
+ ],
+ },
+ }),
+ ],
+ // ...
+ };
+});
+```
+
+### Next.js {/*usage-with-nextjs*/}
+
+Please refer to the [Next.js docs](https://nextjs.org/docs/canary/app/api-reference/next-config-js/reactCompiler) for more information.
+
+### Remix {/*usage-with-remix*/}
+Install `vite-plugin-babel`, and add the compiler's Babel plugin to it:
+
+<TerminalBlock>
+npm install vite-plugin-babel
+</TerminalBlock>
+
+```js {2,14}
+// vite.config.js
+import babel from "vite-plugin-babel";
+
+const ReactCompilerConfig = { /* ... */ };
+
+export default defineConfig({
+ plugins: [
+ remix({ /* ... */}),
+ babel({
+ filter: /\.[jt]sx?$/,
+ babelConfig: {
+ presets: ["@babel/preset-typescript"], // if you use TypeScript
+ plugins: [
+ ["babel-plugin-react-compiler", ReactCompilerConfig],
+ ],
+ },
+ }),
+ ],
+});
+```
+
+### Webpack {/*usage-with-webpack*/}
+
+A community Webpack loader is [now available here](https://github.com/SukkaW/react-compiler-webpack).
+
+### Expo {/*usage-with-expo*/}
+
+Please refer to [Expo's docs](https://docs.expo.dev/preview/react-compiler/) to enable and use the React Compiler in Expo apps.
+
+### Metro (React Native) {/*usage-with-react-native-metro*/}
+
+React Native uses Babel via Metro, so refer to the [Usage with Babel](#usage-with-babel) section for installation instructions.
+
+### Rspack {/*usage-with-rspack*/}
+
+Please refer to [Rspack's docs](https://rspack.dev/guide/tech/react#react-compiler) to enable and use the React Compiler in Rspack apps.
+
+### Rsbuild {/*usage-with-rsbuild*/}
+
+Please refer to [Rsbuild's docs](https://rsbuild.dev/guide/framework/react#react-compiler) to enable and use the React Compiler in Rsbuild apps.
+
+## Troubleshooting {/*troubleshooting*/}
+
+To report issues, please first create a minimal repro on the [React Compiler Playground](https://playground.react.dev/) and include it in your bug report. You can open issues in the [facebook/react](https://github.com/facebook/react/issues) repo.
+
+You can also provide feedback in the React Compiler Working Group by applying to be a member. Please see [the README for more details on joining](https://github.com/reactwg/react-compiler).
+
+### What does the compiler assume? {/*what-does-the-compiler-assume*/}
+
+React Compiler assumes that your code:
+
+1. Is valid, semantic JavaScript.
+2. Tests that nullable/optional values and properties are defined before accessing them (for example, by enabling [`strictNullChecks`](https://www.typescriptlang.org/tsconfig/#strictNullChecks) if using TypeScript), i.e., `if (object.nullableProperty) { object.nullableProperty.foo }` or with optional-chaining `object.nullableProperty?.foo`.
+3. Follows the [Rules of React](https://react.dev/reference/rules).
+
+React Compiler can verify many of the Rules of React statically, and will safely skip compilation when it detects an error. To see the errors we recommend also installing [eslint-plugin-react-compiler](https://www.npmjs.com/package/eslint-plugin-react-compiler).
+
+### How do I know my components have been optimized? {/*how-do-i-know-my-components-have-been-optimized*/}
+
+[React Devtools](/learn/react-developer-tools) (v5.0+) has built-in support for React Compiler and will display a "Memo ✨" badge next to components that have been optimized by the compiler.
+
+### Something is not working after compilation {/*something-is-not-working-after-compilation*/}
+If you have eslint-plugin-react-compiler installed, the compiler will display any violations of the rules of React in your editor. When it does this, it means that the compiler has skipped over optimizing that component or hook. This is perfectly okay, and the compiler can recover and continue optimizing other components in your codebase. **You don't have to fix all ESLint violations straight away.** You can address them at your own pace to increase the amount of components and hooks being optimized.
+
+Due to the flexible and dynamic nature of JavaScript however, it's not possible to comprehensively detect all cases. Bugs and undefined behavior such as infinite loops may occur in those cases.
+
+If your app doesn't work properly after compilation and you aren't seeing any ESLint errors, the compiler may be incorrectly compiling your code. To confirm this, try to make the issue go away by aggressively opting out any component or hook you think might be related via the [`"use no memo"` directive](#opt-out-of-the-compiler-for-a-component).
+
+```js {2}
+function SuspiciousComponent() {
+ "use no memo"; // opts out this component from being compiled by React Compiler
+ // ...
+}
+```
+
+<Note>
+#### `"use no memo"` {/*use-no-memo*/}
+
+`"use no memo"` is a _temporary_ escape hatch that lets you opt-out components and hooks from being compiled by the React Compiler. This directive is not meant to be long lived the same way as eg [`"use client"`](/reference/rsc/use-client) is.
+
+It is not recommended to reach for this directive unless it's strictly necessary. Once you opt-out a component or hook, it is opted-out forever until the directive is removed. This means that even if you fix the code, the compiler will still skip over compiling it unless you remove the directive.
+</Note>
+
+When you make the error go away, confirm that removing the opt out directive makes the issue come back. Then share a bug report with us (you can try to reduce it to a small repro, or if it's open source code you can also just paste the entire source) using the [React Compiler Playground](https://playground.react.dev) so we can identify and help fix the issue.
+
+### Other issues {/*other-issues*/}
+
+Please see https://github.com/reactwg/react-compiler/discussions/7.
diff --git a/src/content/learn/rendering-lists.md b/src/content/learn/rendering-lists.md
index 108e394e2..32f81c447 100644
--- a/src/content/learn/rendering-lists.md
+++ b/src/content/learn/rendering-lists.md
@@ -113,9 +113,11 @@ const people = [{
name: 'Mohammad Abdus Salam',
profession: 'physicist',
}, {
+ id: 3,
name: 'Percy Lavon Julian',
profession: 'chemist',
}, {
+ id: 4,
name: 'Subrahmanyan Chandrasekhar',
profession: 'astrophysicist',
}];
diff --git a/src/content/learn/reusing-logic-with-custom-hooks.md b/src/content/learn/reusing-logic-with-custom-hooks.md
index 13a556c7b..67de5e97f 100644
--- a/src/content/learn/reusing-logic-with-custom-hooks.md
+++ b/src/content/learn/reusing-logic-with-custom-hooks.md
@@ -1899,7 +1899,7 @@ export default function Counter() {
}
```
-You'll need to write your custom Hook in `useCounter.js` and import it into the `Counter.js` file.
+You'll need to write your custom Hook in `useCounter.js` and import it into the `App.js` file.
<Sandpack>
diff --git a/src/content/learn/separating-events-from-effects.md b/src/content/learn/separating-events-from-effects.md
index ac65d2b60..21276c287 100644
--- a/src/content/learn/separating-events-from-effects.md
+++ b/src/content/learn/separating-events-from-effects.md
@@ -44,7 +44,7 @@ function ChatRoom({ roomId }) {
return (
<>
<input value={message} onChange={e => setMessage(e.target.value)} />
- <button onClick={handleSendClick}>Send</button>;
+ <button onClick={handleSendClick}>Send</button>
</>
);
}
diff --git a/src/content/learn/synchronizing-with-effects.md b/src/content/learn/synchronizing-with-effects.md
index f1aa98438..115075161 100644
--- a/src/content/learn/synchronizing-with-effects.md
+++ b/src/content/learn/synchronizing-with-effects.md
@@ -45,7 +45,7 @@ Here and later in this text, capitalized "Effect" refers to the React-specific d
To write an Effect, follow these three steps:
-1. **Declare an Effect.** By default, your Effect will run after every render.
+1. **Declare an Effect.** By default, your Effect will run after every [commit](/learn/render-and-commit).
2. **Specify the Effect dependencies.** Most Effects should only re-run *when needed* rather than after every render. For example, a fade-in animation should only trigger when a component appears. Connecting and disconnecting to a chat room should only happen when the component appears and disappears, or when the chat room changes. You will learn how to control this by specifying *dependencies.*
3. **Add cleanup if needed.** Some Effects need to specify how to stop, undo, or clean up whatever they were doing. For example, "connect" needs "disconnect", "subscribe" needs "unsubscribe", and "fetch" needs either "cancel" or "ignore". You will learn how to do this by returning a *cleanup function*.
@@ -598,9 +598,36 @@ Usually, the answer is to implement the cleanup function. The cleanup function
Most of the Effects you'll write will fit into one of the common patterns below.
+<Pitfall>
+
+#### Don't use refs to prevent Effects from firing {/*dont-use-refs-to-prevent-effects-from-firing*/}
+
+A common pitfall for preventing Effects firing twice in development is to use a `ref` to prevent the Effect from running more than once. For example, you could "fix" the above bug with a `useRef`:
+
+```js {1,3-4}
+ const connectionRef = useRef(null);
+ useEffect(() => {
+ // 🚩 This wont fix the bug!!!
+ if (!connectionRef.current) {
+ connectionRef.current = createConnection();
+ connectionRef.current.connect();
+ }
+ }, []);
+```
+
+This makes it so you only see `"✅ Connecting..."` once in development, but it doesn't fix the bug.
+
+When the user navigates away, the connection still isn't closed and when they navigate back, a new connection is created. As the user navigates across the app, the connections would keep piling up, the same as it would before the "fix".
+
+To fix the bug, it is not enough to just make the Effect run once. The effect needs to work after re-mounting, which means the connection needs to be cleaned up like in the solution above.
+
+See the examples below for how to handle common patterns.
+
+</Pitfall>
+
### Controlling non-React widgets {/*controlling-non-react-widgets*/}
-Sometimes you need to add UI widgets that aren't written to React. For example, let's say you're adding a map component to your page. It has a `setZoomLevel()` method, and you'd like to keep the zoom level in sync with a `zoomLevel` state variable in your React code. Your Effect would look similar to this:
+Sometimes you need to add UI widgets that aren't written in React. For example, let's say you're adding a map component to your page. It has a `setZoomLevel()` method, and you'd like to keep the zoom level in sync with a `zoomLevel` state variable in your React code. Your Effect would look similar to this:
```js
useEffect(() => {
@@ -1573,7 +1600,7 @@ Each render's Effect has its own `ignore` variable. Initially, the `ignore` vari
- Fetching `'Bob'` completes
- The Effect from the `'Bob'` render **does not do anything because its `ignore` flag was set to `true`**
-In addition to ignoring the result of an outdated API call, you can also use [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController) to cancel the requests that are no longer needed. However, by itself this is not enough to protect against race conditions. More asynchronous steps could be chained after the fetch, so using an explicit flag like `ignore` is the most reliable way to fix this type of problems.
+In addition to ignoring the result of an outdated API call, you can also use [`AbortController`](https://developer.mozilla.org/en-US/docs/Web/API/AbortController) to cancel the requests that are no longer needed. However, by itself this is not enough to protect against race conditions. More asynchronous steps could be chained after the fetch, so using an explicit flag like `ignore` is the most reliable way to fix this type of problem.
</Solution>
diff --git a/src/content/learn/thinking-in-react.md b/src/content/learn/thinking-in-react.md
index 0f05a0569..822891e60 100644
--- a/src/content/learn/thinking-in-react.md
+++ b/src/content/learn/thinking-in-react.md
@@ -268,8 +268,8 @@ Now let's run through our strategy for them:
1. **Identify components that use state:**
* `ProductTable` needs to filter the product list based on that state (search text and checkbox value).
* `SearchBar` needs to display that state (search text and checkbox value).
-1. **Find their common parent:** The first parent component both components share is `FilterableProductTable`.
-2. **Decide where the state lives**: We'll keep the filter text and checked state values in `FilterableProductTable`.
+2. **Find their common parent:** The first parent component both components share is `FilterableProductTable`.
+3. **Decide where the state lives**: We'll keep the filter text and checked state values in `FilterableProductTable`.
So the state values will live in `FilterableProductTable`.
diff --git a/src/content/learn/tutorial-tic-tac-toe.md b/src/content/learn/tutorial-tic-tac-toe.md
index d37791456..6487e8007 100644
--- a/src/content/learn/tutorial-tic-tac-toe.md
+++ b/src/content/learn/tutorial-tic-tac-toe.md
@@ -1133,7 +1133,7 @@ Calling the `setSquares` function lets React know the state of the component has
<Note>
-JavaScript supports [closures](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures) which means an inner function (e.g. `handleClick`) has access to variables and functions defined in a outer function (e.g. `Board`). The `handleClick` function can read the `squares` state and call the `setSquares` method because they are both defined inside of the `Board` function.
+JavaScript supports [closures](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures) which means an inner function (e.g. `handleClick`) has access to variables and functions defined in an outer function (e.g. `Board`). The `handleClick` function can read the `squares` state and call the `setSquares` method because they are both defined inside of the `Board` function.
</Note>
@@ -2915,4 +2915,4 @@ If you have extra time or want to practice your new React skills, here are some
1. When someone wins, highlight the three squares that caused the win (and when no one wins, display a message about the result being a draw).
1. Display the location for each move in the format (row, col) in the move history list.
-Throughout this tutorial, you've touched on React concepts including elements, components, props, and state. Now that you've seen how these concepts work when building a game, check out [Thinking in React](/learn/thinking-in-react) to see how the same React concepts work when build an app's UI.
+Throughout this tutorial, you've touched on React concepts including elements, components, props, and state. Now that you've seen how these concepts work when building a game, check out [Thinking in React](/learn/thinking-in-react) to see how the same React concepts work when building an app's UI.
diff --git a/src/content/learn/typescript.md b/src/content/learn/typescript.md
index 034ac0d46..7edf8eb6e 100644
--- a/src/content/learn/typescript.md
+++ b/src/content/learn/typescript.md
@@ -22,7 +22,7 @@ TypeScript is a popular way to add type definitions to JavaScript codebases. Out
All [production-grade React frameworks](/learn/start-a-new-react-project#production-grade-react-frameworks) offer support for using TypeScript. Follow the framework specific guide for installation:
-- [Next.js](https://nextjs.org/docs/pages/building-your-application/configuring/typescript)
+- [Next.js](https://nextjs.org/docs/app/building-your-application/configuring/typescript)
- [Remix](https://remix.run/docs/en/1.19.2/guides/typescript)
- [Gatsby](https://www.gatsbyjs.com/docs/how-to/custom-configuration/typescript/)
- [Expo](https://docs.expo.dev/guides/typescript/)
@@ -137,7 +137,7 @@ The [`useState` Hook](/reference/react/useState) will re-use the value passed in
const [enabled, setEnabled] = useState(false);
```
-Will assign the type of `boolean` to `enabled`, and `setEnabled` will be a function accepting either a `boolean` argument, or a function that returns a `boolean`. If you want to explicitly provide a type for the state, you can do so by providing a type argument to the `useState` call:
+This will assign the type of `boolean` to `enabled`, and `setEnabled` will be a function accepting either a `boolean` argument, or a function that returns a `boolean`. If you want to explicitly provide a type for the state, you can do so by providing a type argument to the `useState` call:
```ts
// Explicitly set the type to "boolean"
@@ -435,7 +435,7 @@ interface ModalRendererProps {
Note, that you cannot use TypeScript to describe that the children are a certain type of JSX elements, so you cannot use the type-system to describe a component which only accepts `<li>` children.
-You can see all an example of both `React.ReactNode` and `React.ReactElement` with the type-checker in [this TypeScript playground](https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBAJQKYEMDG8BmUIjgIilQ3wChSB6CxYmAOmXRgDkIATJOdNJMGAZzgwAFpxAR+8YADswAVwGkZMJFEzpOjDKw4AFHGEEBvUnDhphwADZsi0gFw0mDWjqQBuUgF9yaCNMlENzgAXjgACjADfkctFnYkfQhDAEpQgD44AB42YAA3dKMo5P46C2tbJGkvLIpcgt9-QLi3AEEwMFCItJDMrPTTbIQ3dKywdIB5aU4kKyQQKpha8drhhIGzLLWODbNs3b3s8YAxKBQAcwXpAThMaGWDvbH0gFloGbmrgQfBzYpd1YjQZbEYARkB6zMwO2SHSAAlZlYIBCdtCRkZpHIrFYahQYQD8UYYFA5EhcfjyGYqHAXnJAsIUHlOOUbHYhMIIHJzsI0Qk4P9SLUBuRqXEXEwAKKfRZcNA8PiCfxWACecAAUgBlAAacFm80W-CU11U6h4TgwUv11yShjgJjMLMqDnN9Dilq+nh8pD8AXgCHdMrCkWisVoAet0R6fXqhWKhjKllZVVxMcavpd4Zg7U6Qaj+2hmdG4zeRF10uu-Aeq0LBfLMEe-V+T2L7zLVu+FBWLdLeq+lc7DYFf39deFVOotMCACNOCh1dq219a+30uC8YWoZsRyuEdjkevR8uvoVMdjyTWt4WiSSydXD4NqZP4AymeZE072ZzuUeZQKheQgA).
+You can see an example of both `React.ReactNode` and `React.ReactElement` with the type-checker in [this TypeScript playground](https://www.typescriptlang.org/play?#code/JYWwDg9gTgLgBAJQKYEMDG8BmUIjgIilQ3wChSB6CxYmAOmXRgDkIATJOdNJMGAZzgwAFpxAR+8YADswAVwGkZMJFEzpOjDKw4AFHGEEBvUnDhphwADZsi0gFw0mDWjqQBuUgF9yaCNMlENzgAXjgACjADfkctFnYkfQhDAEpQgD44AB42YAA3dKMo5P46C2tbJGkvLIpcgt9-QLi3AEEwMFCItJDMrPTTbIQ3dKywdIB5aU4kKyQQKpha8drhhIGzLLWODbNs3b3s8YAxKBQAcwXpAThMaGWDvbH0gFloGbmrgQfBzYpd1YjQZbEYARkB6zMwO2SHSAAlZlYIBCdtCRkZpHIrFYahQYQD8UYYFA5EhcfjyGYqHAXnJAsIUHlOOUbHYhMIIHJzsI0Qk4P9SLUBuRqXEXEwAKKfRZcNA8PiCfxWACecAAUgBlAAacFm80W-CU11U6h4TgwUv11yShjgJjMLMqDnN9Dilq+nh8pD8AXgCHdMrCkWisVoAet0R6fXqhWKhjKllZVVxMcavpd4Zg7U6Qaj+2hmdG4zeRF10uu-Aeq0LBfLMEe-V+T2L7zLVu+FBWLdLeq+lc7DYFf39deFVOotMCACNOCh1dq219a+30uC8YWoZsRyuEdjkevR8uvoVMdjyTWt4WiSSydXD4NqZP4AymeZE072ZzuUeZQKheQgA).
### Style Props {/*typing-style-props*/}
@@ -456,7 +456,7 @@ We recommend the following resources:
- [The TypeScript handbook](https://www.typescriptlang.org/docs/handbook/) is the official documentation for TypeScript, and covers most key language features.
- - [The TypeScript release notes](https://devblogs.microsoft.com/typescript/) covers a each new features in-depth.
+ - [The TypeScript release notes](https://devblogs.microsoft.com/typescript/) cover new features in depth.
- [React TypeScript Cheatsheet](https://react-typescript-cheatsheet.netlify.app/) is a community-maintained cheatsheet for using TypeScript with React, covering a lot of useful edge cases and providing more breadth than this document.
diff --git a/src/content/learn/updating-objects-in-state.md b/src/content/learn/updating-objects-in-state.md
index 923e4e181..93ea93bd2 100644
--- a/src/content/learn/updating-objects-in-state.md
+++ b/src/content/learn/updating-objects-in-state.md
@@ -57,6 +57,7 @@ This example holds an object in state to represent the current pointer position.
```js
import { useState } from 'react';
+
export default function MovingDot() {
const [position, setPosition] = useState({
x: 0,
@@ -127,6 +128,7 @@ Notice how the red dot now follows your pointer when you touch or hover over the
```js
import { useState } from 'react';
+
export default function MovingDot() {
const [position, setPosition] = useState({
x: 0,
@@ -377,7 +379,7 @@ Note that the `...` spread syntax is "shallow"--it only copies things one level
#### Using a single event handler for multiple fields {/*using-a-single-event-handler-for-multiple-fields*/}
-You can also use the `[` and `]` braces inside your object definition to specify a property with dynamic name. Here is the same example, but with a single event handler instead of three different ones:
+You can also use the `[` and `]` braces inside your object definition to specify a property with a dynamic name. Here is the same example, but with a single event handler instead of three different ones:
<Sandpack>
diff --git a/src/content/learn/you-might-not-need-an-effect.md b/src/content/learn/you-might-not-need-an-effect.md
index 66cdc3117..a009793ab 100644
--- a/src/content/learn/you-might-not-need-an-effect.md
+++ b/src/content/learn/you-might-not-need-an-effect.md
@@ -408,9 +408,9 @@ function Game() {
There are two problems with this code.
-One problem is that it is very inefficient: the component (and its children) have to re-render between each `set` call in the chain. In the example above, in the worst case (`setCard` → render → `setGoldCardCount` → render → `setRound` → render → `setIsGameOver` → render) there are three unnecessary re-renders of the tree below.
+The first problem is that it is very inefficient: the component (and its children) have to re-render between each `set` call in the chain. In the example above, in the worst case (`setCard` → render → `setGoldCardCount` → render → `setRound` → render → `setIsGameOver` → render) there are three unnecessary re-renders of the tree below.
-Even if it weren't slow, as your code evolves, you will run into cases where the "chain" you wrote doesn't fit the new requirements. Imagine you are adding a way to step through the history of the game moves. You'd do it by updating each state variable to a value from the past. However, setting the `card` state to a value from the past would trigger the Effect chain again and change the data you're showing. Such code is often rigid and fragile.
+The second problem is that even if it weren't slow, as your code evolves, you will run into cases where the "chain" you wrote doesn't fit the new requirements. Imagine you are adding a way to step through the history of the game moves. You'd do it by updating each state variable to a value from the past. However, setting the `card` state to a value from the past would trigger the Effect chain again and change the data you're showing. Such code is often rigid and fragile.
In this case, it's better to calculate what you can during rendering, and adjust the state in the event handler:
diff --git a/src/content/reference/react-dom/client/createRoot.md b/src/content/reference/react-dom/client/createRoot.md
index afddb4177..b336b6e5e 100644
--- a/src/content/reference/react-dom/client/createRoot.md
+++ b/src/content/reference/react-dom/client/createRoot.md
@@ -45,7 +45,9 @@ An app fully built with React will usually only have one `createRoot` call for i
* **optional** `options`: An object with options for this React root.
- * **optional** `onRecoverableError`: Callback called when React automatically recovers from errors.
+ * <CanaryBadge title="This feature is only available in the Canary channel" /> **optional** `onCaughtError`: Callback called when React catches an error in an Error Boundary. Called with the `error` caught by the Error Boundary, and an `errorInfo` object containing the `componentStack`.
+ * <CanaryBadge title="This feature is only available in the Canary channel" /> **optional** `onUncaughtError`: Callback called when an error is thrown and not caught by an Error Boundary. Called with the `error` that was thrown, and an `errorInfo` object containing the `componentStack`.
+ * **optional** `onRecoverableError`: Callback called when React automatically recovers from errors. Called with an `error` React throws, and an `errorInfo` object containing the `componentStack`. Some recoverable errors may include the original error cause as `error.cause`.
* **optional** `identifierPrefix`: A string prefix React uses for IDs generated by [`useId`.](/reference/react/useId) Useful to avoid conflicts when using multiple roots on the same page.
#### Returns {/*returns*/}
@@ -342,6 +344,797 @@ export default function App({counter}) {
It is uncommon to call `render` multiple times. Usually, your components will [update state](/reference/react/useState) instead.
+### Show a dialog for uncaught errors {/*show-a-dialog-for-uncaught-errors*/}
+
+<Canary>
+
+`onUncaughtError` is only available in the latest React Canary release.
+
+</Canary>
+
+By default, React will log all uncaught errors to the console. To implement your own error reporting, you can provide the optional `onUncaughtError` root option:
+
+```js [[1, 6, "onUncaughtError"], [2, 6, "error", 1], [3, 6, "errorInfo"], [4, 10, "componentStack"]]
+import { createRoot } from 'react-dom/client';
+
+const root = createRoot(
+ document.getElementById('root'),
+ {
+ onUncaughtError: (error, errorInfo) => {
+ console.error(
+ 'Uncaught error',
+ error,
+ errorInfo.componentStack
+ );
+ }
+ }
+);
+root.render(<App />);
+```
+
+The <CodeStep step={1}>onUncaughtError</CodeStep> option is a function called with two arguments:
+
+1. The <CodeStep step={2}>error</CodeStep> that was thrown.
+2. An <CodeStep step={3}>errorInfo</CodeStep> object that contains the <CodeStep step={4}>componentStack</CodeStep> of the error.
+
+You can use the `onUncaughtError` root option to display error dialogs:
+
+<Sandpack>
+
+```html index.html hidden
+<!DOCTYPE html>
+<html>
+<head>
+ <title>My app
+
+
+
+
+
+
+
+
+
+
+
+
This error occurred at:
+
+
Call stack:
+
+
+
+
This error is not dismissible.
+
+
+
+
+
+