`.
- Usually, you will use refs for non-destructive actions like focusing, scrolling, or measuring DOM elements.
-- A component doesn't expose its DOM nodes by default. You can opt into exposing a DOM node by using `forwardRef` and passing the second `ref` argument down to a specific node.
+- A component doesn't expose its DOM nodes by default. You can opt into exposing a DOM node by using the `ref` prop.
- Avoid changing DOM nodes managed by React.
- If you do modify DOM nodes managed by React, modify parts that React has no reason to update.
@@ -1093,7 +1049,7 @@ Make it so that clicking the "Search" button puts focus into the field. Note tha
-You'll need `forwardRef` to opt into exposing a DOM node from your own component like `SearchInput`.
+You'll need to pass `ref` as a prop to opt into exposing a DOM node from your own component like `SearchInput`.
@@ -1178,18 +1134,14 @@ export default function SearchButton({ onClick }) {
```
```js src/SearchInput.js
-import { forwardRef } from 'react';
-
-export default forwardRef(
- function SearchInput(props, ref) {
- return (
-
- );
- }
-);
+export default function SearchInput({ ref }) {
+ return (
+
+ );
+}
```
```css
diff --git a/src/content/learn/passing-data-deeply-with-context.md b/src/content/learn/passing-data-deeply-with-context.md
index 1aea87b35..e81678c8e 100644
--- a/src/content/learn/passing-data-deeply-with-context.md
+++ b/src/content/learn/passing-data-deeply-with-context.md
@@ -468,15 +468,15 @@ import { LevelContext } from './LevelContext.js';
export default function Section({ level, children }) {
return (
);
}
```
-This tells React: "if any component inside this `
` asks for `LevelContext`, give them this `level`." The component will use the value of the nearest `` in the UI tree above it.
+This tells React: "if any component inside this `` asks for `LevelContext`, give them this `level`." The component will use the value of the nearest `` in the UI tree above it.
@@ -514,9 +514,9 @@ import { LevelContext } from './LevelContext.js';
export default function Section({ level, children }) {
return (
);
}
@@ -567,7 +567,7 @@ export const LevelContext = createContext(1);
It's the same result as the original code, but you did not need to pass the `level` prop to each `Heading` component! Instead, it "figures out" its heading level by asking the closest `Section` above:
1. You pass a `level` prop to the ``.
-2. `Section` wraps its children into ``.
+2. `Section` wraps its children into ``.
3. `Heading` asks the closest value of `LevelContext` above with `useContext(LevelContext)`.
## Using and providing context from the same component {/*using-and-providing-context-from-the-same-component*/}
@@ -595,9 +595,9 @@ export default function Section({ children }) {
const level = useContext(LevelContext);
return (
);
}
@@ -643,9 +643,9 @@ export default function Section({ children }) {
const level = useContext(LevelContext);
return (
);
}
@@ -776,9 +776,9 @@ export default function Section({ children, isFancy }) {
'section ' +
(isFancy ? 'fancy' : '')
}>
-
+
{children}
-
+
);
}
@@ -868,7 +868,7 @@ In general, if some information is needed by distant components in different par
* To pass context:
1. Create and export it with `export const MyContext = createContext(defaultValue)`.
2. Pass it to the `useContext(MyContext)` Hook to read it in any child component, no matter how deep.
- 3. Wrap children into `
` to provide it from a parent.
+ 3. Wrap children into `` to provide it from a parent.
* Context passes through any components in the middle.
* Context lets you write components that "adapt to their surroundings".
* Before you use context, try passing props or passing JSX as `children`.
@@ -1022,7 +1022,7 @@ li {
Remove `imageSize` prop from all the components.
-Create and export `ImageSizeContext` from `Context.js`. Then wrap the List into `` to pass the value down, and `useContext(ImageSizeContext)` to read it in the `PlaceImage`:
+Create and export `ImageSizeContext` from `Context.js`. Then wrap the List into `` to pass the value down, and `useContext(ImageSizeContext)` to read it in the `PlaceImage`:
@@ -1036,7 +1036,7 @@ export default function App() {
const [isLarge, setIsLarge] = useState(false);
const imageSize = isLarge ? 150 : 100;
return (
-
-
+
)
}
diff --git a/src/content/learn/react-compiler.md b/src/content/learn/react-compiler.md
index 5362d69e1..7c46673e7 100644
--- a/src/content/learn/react-compiler.md
+++ b/src/content/learn/react-compiler.md
@@ -311,7 +311,7 @@ export default defineConfig({
### Webpack {/*usage-with-webpack*/}
-A community Webpack loader is [now available here](https://github.com/SukkaW/react-compiler-webpack).
+A community webpack loader is [now available here](https://github.com/SukkaW/react-compiler-webpack).
### Expo {/*usage-with-expo*/}
@@ -347,7 +347,7 @@ React Compiler can verify many of the Rules of React statically, and will safely
### 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.
+[React DevTools](/learn/react-developer-tools) (v5.0+) and [React Native DevTools](https://reactnative.dev/docs/react-native-devtools) have 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.
diff --git a/src/content/learn/react-developer-tools.md b/src/content/learn/react-developer-tools.md
index 9202d8412..75406c5c6 100644
--- a/src/content/learn/react-developer-tools.md
+++ b/src/content/learn/react-developer-tools.md
@@ -54,7 +54,7 @@ Reload your website in the browser now to view it in developer tools.
## Mobile (React Native) {/*mobile-react-native*/}
-To inspect apps built with [React Native](https://reactnative.dev/), you can use [React Native DevTools](https://reactnative.dev/docs/debugging/react-native-devtools), the built-in debugger that deeply integrates React Developer Tools. All features work identically to the browser extension, including native element highlighting and selection.
+To inspect apps built with [React Native](https://reactnative.dev/), you can use [React Native DevTools](https://reactnative.dev/docs/react-native-devtools), the built-in debugger that deeply integrates React Developer Tools. All features work identically to the browser extension, including native element highlighting and selection.
[Learn more about debugging in React Native.](https://reactnative.dev/docs/debugging)
diff --git a/src/content/learn/render-and-commit.md b/src/content/learn/render-and-commit.md
index 3f0593599..f9b05e185 100644
--- a/src/content/learn/render-and-commit.md
+++ b/src/content/learn/render-and-commit.md
@@ -70,7 +70,7 @@ Try commenting out the `root.render()` call and see the component disappear!
Once the component has been initially rendered, you can trigger further renders by updating its state with the [`set` function.](/reference/react/useState#setstate) Updating your component's state automatically queues a render. (You can imagine these as a restaurant guest ordering tea, dessert, and all sorts of things after putting in their first order, depending on the state of their thirst or hunger.)
-
+
@@ -84,7 +84,7 @@ After you trigger a render, React calls your components to figure out what to di
This process is recursive: if the updated component returns some other component, React will render _that_ component next, and if that component also returns something, it will render _that_ component next, and so on. The process will continue until there are no more nested components and React knows exactly what should be displayed on screen.
-In the following example, React will call `Gallery()` and `Image()` several times:
+In the following example, React will call `Gallery()` and `Image()` several times:
@@ -148,9 +148,9 @@ The default behavior of rendering all components nested within the updated compo
## Step 3: React commits changes to the DOM {/*step-3-react-commits-changes-to-the-dom*/}
-After rendering (calling) your components, React will modify the DOM.
+After rendering (calling) your components, React will modify the DOM.
-* **For the initial render,** React will use the [`appendChild()`](https://developer.mozilla.org/docs/Web/API/Node/appendChild) DOM API to put all the DOM nodes it has created on screen.
+* **For the initial render,** React will use the [`appendChild()`](https://developer.mozilla.org/docs/Web/API/Node/appendChild) DOM API to put all the DOM nodes it has created on screen.
* **For re-renders,** React will apply the minimal necessary operations (calculated while rendering!) to make the DOM match the latest rendering output.
**React only changes the DOM nodes if there's a difference between renders.** For example, here is a component that re-renders with different props passed from its parent every second. Notice how you can add some text into the ``, updating its `value`, but the text doesn't disappear when the component re-renders:
diff --git a/src/content/learn/setup.md b/src/content/learn/setup.md
new file mode 100644
index 000000000..2c46ee148
--- /dev/null
+++ b/src/content/learn/setup.md
@@ -0,0 +1,28 @@
+---
+title: Setup
+---
+
+
+React integrates with tools like editors, TypeScript, browser extensions, and compilers. This section will help you get your environment set up.
+
+
+
+## Editor Setup {/*editor-setup*/}
+
+See our [recommended editors](/learn/editor-setup) and learn how to set them up to work with React.
+
+## Using TypeScript {/*using-typescript*/}
+
+TypeScript is a popular way to add type definitions to JavaScript codebases. [Learn how to integrate TypeScript into your React projects](/learn/typescript).
+
+## React Developer Tools {/*react-developer-tools*/}
+
+React Developer Tools is a browser extension that can inspect React components, edit props and state, and identify performance problems. Learn how to install it [here](learn/react-developer-tools).
+
+## React Compiler {/*react-compiler*/}
+
+React Compiler is a tool that automatically optimizes your React app. [Learn more](/learn/react-compiler).
+
+## Next steps {/*next-steps*/}
+
+Head to the [Quick Start](/learn) guide for a tour of the most important React concepts you will encounter every day.
diff --git a/src/content/learn/start-a-new-react-project.md b/src/content/learn/start-a-new-react-project.md
deleted file mode 100644
index bd5ba6c50..000000000
--- a/src/content/learn/start-a-new-react-project.md
+++ /dev/null
@@ -1,130 +0,0 @@
----
-title: Start a New React Project
----
-
-
-
-If you want to build a new app or a new website fully with React, we recommend picking one of the React-powered frameworks popular in the community.
-
-
-
-
-You can use React without a framework, however we’ve found that most apps and sites eventually build solutions to common problems such as code-splitting, routing, data fetching, and generating HTML. These problems are common to all UI libraries, not just React.
-
-By starting with a framework, you can get started with React quickly, and avoid essentially building your own framework later.
-
-
-
-#### Can I use React without a framework? {/*can-i-use-react-without-a-framework*/}
-
-You can definitely use React without a framework--that's how you'd [use React for a part of your page.](/learn/add-react-to-an-existing-project#using-react-for-a-part-of-your-existing-page) **However, if you're building a new app or a site fully with React, we recommend using a framework.**
-
-Here's why.
-
-Even if you don't need routing or data fetching at first, you'll likely want to add some libraries for them. As your JavaScript bundle grows with every new feature, you might have to figure out how to split code for every route individually. As your data fetching needs get more complex, you are likely to encounter server-client network waterfalls that make your app feel very slow. As your audience includes more users with poor network conditions and low-end devices, you might need to generate HTML from your components to display content early--either on the server, or during the build time. Changing your setup to run some of your code on the server or during the build can be very tricky.
-
-**These problems are not React-specific. This is why Svelte has SvelteKit, Vue has Nuxt, and so on.** To solve these problems on your own, you'll need to integrate your bundler with your router and with your data fetching library. It's not hard to get an initial setup working, but there are a lot of subtleties involved in making an app that loads quickly even as it grows over time. You'll want to send down the minimal amount of app code but do so in a single client–server roundtrip, in parallel with any data required for the page. You'll likely want the page to be interactive before your JavaScript code even runs, to support progressive enhancement. You may want to generate a folder of fully static HTML files for your marketing pages that can be hosted anywhere and still work with JavaScript disabled. Building these capabilities yourself takes real work.
-
-**React frameworks on this page solve problems like these by default, with no extra work from your side.** They let you start very lean and then scale your app with your needs. Each React framework has a community, so finding answers to questions and upgrading tooling is easier. Frameworks also give structure to your code, helping you and others retain context and skills between different projects. Conversely, with a custom setup it's easier to get stuck on unsupported dependency versions, and you'll essentially end up creating your own framework—albeit one with no community or upgrade path (and if it's anything like the ones we've made in the past, more haphazardly designed).
-
-If your app has unusual constraints not served well by these frameworks, or you prefer to solve these problems yourself, you can roll your own custom setup with React. Grab `react` and `react-dom` from npm, set up your custom build process with a bundler like [Vite](https://vitejs.dev/) or [Parcel](https://parceljs.org/), and add other tools as you need them for routing, static generation or server-side rendering, and more.
-
-
-
-## Production-grade React frameworks {/*production-grade-react-frameworks*/}
-
-These frameworks support all the features you need to deploy and scale your app in production and are working towards supporting our [full-stack architecture vision](#which-features-make-up-the-react-teams-full-stack-architecture-vision). All of the frameworks we recommend are open source with active communities for support, and can be deployed to your own server or a hosting provider. If you’re a framework author interested in being included on this list, [please let us know](https://github.com/reactjs/react.dev/issues/new?assignees=&labels=type%3A+framework&projects=&template=3-framework.yml&title=%5BFramework%5D%3A+).
-
-### Next.js {/*nextjs-pages-router*/}
-
-**[Next.js' Pages Router](https://nextjs.org/) is a full-stack React framework.** It's versatile and lets you create React apps of any size--from a mostly static blog to a complex dynamic application. To create a new Next.js project, run in your terminal:
-
-
-npx create-next-app@latest
-
-
-If you're new to Next.js, check out the [learn Next.js course.](https://nextjs.org/learn)
-
-Next.js is maintained by [Vercel](https://vercel.com/). You can [deploy a Next.js app](https://nextjs.org/docs/app/building-your-application/deploying) to any Node.js or serverless hosting, or to your own server. Next.js also supports a [static export](https://nextjs.org/docs/pages/building-your-application/deploying/static-exports) which doesn't require a server.
-
-### Remix {/*remix*/}
-
-**[Remix](https://remix.run/) is a full-stack React framework with nested routing.** It lets you break your app into nested parts that can load data in parallel and refresh in response to the user actions. To create a new Remix project, run:
-
-
-npx create-remix
-
-
-If you're new to Remix, check out the Remix [blog tutorial](https://remix.run/docs/en/main/tutorials/blog) (short) and [app tutorial](https://remix.run/docs/en/main/tutorials/jokes) (long).
-
-Remix is maintained by [Shopify](https://www.shopify.com/). When you create a Remix project, you need to [pick your deployment target](https://remix.run/docs/en/main/guides/deployment). You can deploy a Remix app to any Node.js or serverless hosting by using or writing an [adapter](https://remix.run/docs/en/main/other-api/adapter).
-
-### Gatsby {/*gatsby*/}
-
-**[Gatsby](https://www.gatsbyjs.com/) is a React framework for fast CMS-backed websites.** Its rich plugin ecosystem and its GraphQL data layer simplify integrating content, APIs, and services into one website. To create a new Gatsby project, run:
-
-
-npx create-gatsby
-
-
-If you're new to Gatsby, check out the [Gatsby tutorial.](https://www.gatsbyjs.com/docs/tutorial/)
-
-Gatsby is maintained by [Netlify](https://www.netlify.com/). You can [deploy a fully static Gatsby site](https://www.gatsbyjs.com/docs/how-to/previews-deploys-hosting) to any static hosting. If you opt into using server-only features, make sure your hosting provider supports them for Gatsby.
-
-### Expo (for native apps) {/*expo*/}
-
-**[Expo](https://expo.dev/) is a React framework that lets you create universal Android, iOS, and web apps with truly native UIs.** It provides an SDK for [React Native](https://reactnative.dev/) that makes the native parts easier to use. To create a new Expo project, run:
-
-
-npx create-expo-app
-
-
-If you're new to Expo, check out the [Expo tutorial](https://docs.expo.dev/tutorial/introduction/).
-
-Expo is maintained by [Expo (the company)](https://expo.dev/about). Building apps with Expo is free, and you can submit them to the Google and Apple app stores without restrictions. Expo additionally provides opt-in paid cloud services.
-
-## Bleeding-edge React frameworks {/*bleeding-edge-react-frameworks*/}
-
-As we've explored how to continue improving React, we realized that integrating React more closely with frameworks (specifically, with routing, bundling, and server technologies) is our biggest opportunity to help React users build better apps. The Next.js team has agreed to collaborate with us in researching, developing, integrating, and testing framework-agnostic bleeding-edge React features like [React Server Components.](/blog/2023/03/22/react-labs-what-we-have-been-working-on-march-2023#react-server-components)
-
-These features are getting closer to being production-ready every day, and we've been in talks with other bundler and framework developers about integrating them. Our hope is that in a year or two, all frameworks listed on this page will have full support for these features. (If you're a framework author interested in partnering with us to experiment with these features, please let us know!)
-
-### Next.js (App Router) {/*nextjs-app-router*/}
-
-**[Next.js's App Router](https://nextjs.org/docs) is a redesign of the Next.js APIs aiming to fulfill the React team’s full-stack architecture vision.** It lets you fetch data in asynchronous components that run on the server or even during the build.
-
-Next.js is maintained by [Vercel](https://vercel.com/). You can [deploy a Next.js app](https://nextjs.org/docs/app/building-your-application/deploying) to any Node.js or serverless hosting, or to your own server. Next.js also supports [static export](https://nextjs.org/docs/app/building-your-application/deploying/static-exports) which doesn't require a server.
-
-
-
-#### Which features make up the React team’s full-stack architecture vision? {/*which-features-make-up-the-react-teams-full-stack-architecture-vision*/}
-
-Next.js's App Router bundler fully implements the official [React Server Components specification](https://github.com/reactjs/rfcs/blob/main/text/0188-server-components.md). This lets you mix build-time, server-only, and interactive components in a single React tree.
-
-For example, you can write a server-only React component as an `async` function that reads from a database or from a file. Then you can pass data down from it to your interactive components:
-
-```js
-// This component runs *only* on the server (or during the build).
-async function Talks({ confId }) {
- // 1. You're on the server, so you can talk to your data layer. API endpoint not required.
- const talks = await db.Talks.findAll({ confId });
-
- // 2. Add any amount of rendering logic. It won't make your JavaScript bundle larger.
- const videos = talks.map(talk => talk.video);
-
- // 3. Pass the data down to the components that will run in the browser.
- return ;
-}
-```
-
-Next.js's App Router also integrates [data fetching with Suspense](/blog/2022/03/29/react-v18#suspense-in-data-frameworks). This lets you specify a loading state (like a skeleton placeholder) for different parts of your user interface directly in your React tree:
-
-```js
-}>
-
-
-```
-
-Server Components and Suspense are React features rather than Next.js features. However, adopting them at the framework level requires buy-in and non-trivial implementation work. At the moment, the Next.js App Router is the most complete implementation. The React team is working with bundler developers to make these features easier to implement in the next generation of frameworks.
-
-
diff --git a/src/content/learn/state-a-components-memory.md b/src/content/learn/state-a-components-memory.md
index 75a1fd0b9..73d46bdab 100644
--- a/src/content/learn/state-a-components-memory.md
+++ b/src/content/learn/state-a-components-memory.md
@@ -1452,7 +1452,7 @@ If your linter is [configured for React](/learn/editor-setup#linting), you shoul
#### Remove unnecessary state {/*remove-unnecessary-state*/}
-When the button is clicked, this example should ask for the user's name and then display an alert greeting them. You tried to use state to keep the name, but for some reason it always shows "Hello, !".
+When the button is clicked, this example should ask for the user's name and then display an alert greeting them. You tried to use state to keep the name, but for some reason the first time it shows "Hello, !", and then "Hello, [name]!" with the previous input every time after.
To fix this code, remove the unnecessary state variable. (We will discuss about [why this didn't work](/learn/state-as-a-snapshot) later.)
diff --git a/src/content/learn/tutorial-tic-tac-toe.md b/src/content/learn/tutorial-tic-tac-toe.md
index 6487e8007..1c61d180a 100644
--- a/src/content/learn/tutorial-tic-tac-toe.md
+++ b/src/content/learn/tutorial-tic-tac-toe.md
@@ -295,7 +295,7 @@ export default function Square() {
}
```
-The _browser_ section should be displaying a square with a X in it like this:
+The _browser_ section should be displaying a square with an X in it like this:
@@ -1325,7 +1325,7 @@ Let's recap what happens when a user clicks the top left square on your board to
1. `handleClick` uses the argument (`0`) to update the first element of the `squares` array from `null` to `X`.
1. The `squares` state of the `Board` component was updated, so the `Board` and all of its children re-render. This causes the `value` prop of the `Square` component with index `0` to change from `null` to `X`.
-In the end the user sees that the upper left square has changed from empty to having a `X` after clicking it.
+In the end the user sees that the upper left square has changed from empty to having an `X` after clicking it.
@@ -1406,7 +1406,7 @@ But wait, there's a problem. Try clicking on the same square multiple times:
The `X` is overwritten by an `O`! While this would add a very interesting twist to the game, we're going to stick to the original rules for now.
-When you mark a square with a `X` or an `O` you aren't first checking to see if the square already has a `X` or `O` value. You can fix this by *returning early*. You'll check to see if the square already has a `X` or an `O`. If the square is already filled, you will `return` in the `handleClick` function early--before it tries to update the board state.
+When you mark a square with an `X` or an `O` you aren't first checking to see if the square already has an `X` or `O` value. You can fix this by *returning early*. You'll check to see if the square already has an `X` or an `O`. If the square is already filled, you will `return` in the `handleClick` function early--before it tries to update the board state.
```js {2,3,4}
function handleClick(i) {
@@ -1556,7 +1556,7 @@ It does not matter whether you define `calculateWinner` before or after the `Boa
-You will call `calculateWinner(squares)` in the `Board` component's `handleClick` function to check if a player has won. You can perform this check at the same time you check if a user has clicked a square that already has a `X` or and `O`. We'd like to return early in both cases:
+You will call `calculateWinner(squares)` in the `Board` component's `handleClick` function to check if a player has won. You can perform this check at the same time you check if a user has clicked a square that already has an `X` or an `O`. We'd like to return early in both cases:
```js {2}
function handleClick(i) {
diff --git a/src/content/reference/react-dom/client/createRoot.md b/src/content/reference/react-dom/client/createRoot.md
index a2bef6bf2..0a3933949 100644
--- a/src/content/reference/react-dom/client/createRoot.md
+++ b/src/content/reference/react-dom/client/createRoot.md
@@ -144,7 +144,7 @@ Usually, you only need to run this code once at startup. It will:
-```html index.html
+```html public/index.html
My app
@@ -344,775 +344,127 @@ 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*/}
-
-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';
+### Error logging in production {/*error-logging-in-production*/}
-const root = createRoot(
- document.getElementById('root'),
- {
- onUncaughtError: (error, errorInfo) => {
- console.error(
- 'Uncaught error',
- error,
- errorInfo.componentStack
- );
- }
- }
-);
-root.render();
-```
-
-The onUncaughtError option is a function called with two arguments:
-
-1. The error that was thrown.
-2. An errorInfo object that contains the componentStack of the error.
+By default, React will log all errors to the console. To implement your own error reporting, you can provide the optional error handler root options `onUncaughtError`, `onCaughtError` and `onRecoverableError`:
-You can use the `onUncaughtError` root option to display error dialogs:
-
-
-
-```html index.html hidden
-
-
-
- My app
-
-
-
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
- This error shows the error dialog:
-
-
- );
-}
-```
-
-
-
-
-### Displaying Error Boundary errors {/*displaying-error-boundary-errors*/}
-
-By default, React will log all errors caught by an Error Boundary to `console.error`. To override this behavior, you can provide the optional `onCaughtError` root option to handle errors caught by an [Error Boundary](/reference/react/Component#catching-rendering-errors-with-an-error-boundary):
-
-```js [[1, 6, "onCaughtError"], [2, 6, "error", 1], [3, 6, "errorInfo"], [4, 10, "componentStack"]]
-import { createRoot } from 'react-dom/client';
-
-const root = createRoot(
- document.getElementById('root'),
- {
- onCaughtError: (error, errorInfo) => {
- console.error(
- 'Caught error',
- error,
- errorInfo.componentStack
- );
- }
- }
-);
-root.render();
```
The onCaughtError option is a function called with two arguments:
-1. The error that was caught by the boundary.
+1. The error that was thrown.
2. An errorInfo object that contains the componentStack of the error.
-You can use the `onCaughtError` root option to display error dialogs or filter known errors from logging:
+Together with `onUncaughtError` and `onRecoverableError`, you can can implement your own error reporting system:
-```html index.html hidden
-
-
-
- My app
-
-
-
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
-
Error Boundary
-
Something went wrong.
-
-
Something went wrong.
;
}
+ return this.props.children;
}
-);
-root.render();
-```
-
-The onRecoverableError option is a function called with two arguments:
-
-1. The error that React throws. Some errors may include the original cause as error.cause.
-2. An errorInfo object that contains the componentStack of the error.
-
-You can use the `onRecoverableError` root option to display error dialogs:
-
-
-
-```html index.html hidden
-
-
-
- My app
-
-
-
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
This component threw an error, but recovered during a second render.
- Since it recovered, no Error Boundary was shown, but onRecoverableError was used to show an error dialog.
-
-
+
+ {triggerUncaughtError && }
+
+ {triggerCaughtError && (
+
+
+
+ )}
);
}
-
-function fallbackRender() {
- return (
-
-
Error Boundary
-
Something went wrong.
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
This error shows the error dialog:
- This error shows the error dialog:
-
-
- );
-}
-```
-
-
-
-
-### Displaying Error Boundary errors {/*displaying-error-boundary-errors*/}
-
-By default, React will log all errors caught by an Error Boundary to `console.error`. To override this behavior, you can provide the optional `onCaughtError` root option for errors caught by an [Error Boundary](/reference/react/Component#catching-rendering-errors-with-an-error-boundary):
-
-```js [[1, 7, "onCaughtError"], [2, 7, "error", 1], [3, 7, "errorInfo"], [4, 11, "componentStack"]]
-import { hydrateRoot } from 'react-dom/client';
+import { Component, useState } from "react";
-const root = hydrateRoot(
- document.getElementById('root'),
- ,
- {
- onCaughtError: (error, errorInfo) => {
- console.error(
- 'Caught error',
- error,
- errorInfo.componentStack
- );
- }
- }
-);
-root.render();
-```
-
-The onCaughtError option is a function called with two arguments:
-
-1. The error that was caught by the boundary.
-2. An errorInfo object that contains the componentStack of the error.
-
-You can use the `onCaughtError` root option to display error dialogs or filter known errors from logging:
-
-
-
-```html index.html hidden
-
-
-
- My app
-
-
-
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
This error will not show the error dialog:This error will show the error dialog:
-
-
-```
-
-```css src/styles.css active
-label, button { display: block; margin-bottom: 20px; }
-html, body { min-height: 300px; }
-
-#error-dialog {
- position: absolute;
- top: 0;
- right: 0;
- bottom: 0;
- left: 0;
- background-color: white;
- padding: 15px;
- opacity: 0.9;
- text-wrap: wrap;
- overflow: scroll;
-}
-
-.text-red {
- color: red;
-}
-
-.-mb-20 {
- margin-bottom: -20px;
-}
-
-.mb-0 {
- margin-bottom: 0;
-}
-
-.mb-10 {
- margin-bottom: 10px;
-}
-
-pre {
- text-wrap: wrap;
+function Boom() {
+ foo.bar = "baz";
}
-pre.nowrap {
- text-wrap: nowrap;
-}
+class ErrorBoundary extends Component {
+ state = { hasError: false };
-.hidden {
- display: none;
-}
-```
-
-```js src/reportError.js hidden
-function reportError({ title, error, componentStack, dismissable }) {
- const errorDialog = document.getElementById("error-dialog");
- const errorTitle = document.getElementById("error-title");
- const errorMessage = document.getElementById("error-message");
- const errorBody = document.getElementById("error-body");
- const errorComponentStack = document.getElementById("error-component-stack");
- const errorStack = document.getElementById("error-stack");
- const errorClose = document.getElementById("error-close");
- const errorCause = document.getElementById("error-cause");
- const errorCauseMessage = document.getElementById("error-cause-message");
- const errorCauseStack = document.getElementById("error-cause-stack");
- const errorNotDismissible = document.getElementById("error-not-dismissible");
-
- // Set the title
- errorTitle.innerText = title;
-
- // Display error message and body
- const [heading, body] = error.message.split(/\n(.*)/s);
- errorMessage.innerText = heading;
- if (body) {
- errorBody.innerText = body;
- } else {
- errorBody.innerText = '';
- }
-
- // Display component stack
- errorComponentStack.innerText = componentStack;
-
- // Display the call stack
- // Since we already displayed the message, strip it, and the first Error: line.
- errorStack.innerText = error.stack.replace(error.message, '').split(/\n(.*)/s)[1];
-
- // Display the cause, if available
- if (error.cause) {
- errorCauseMessage.innerText = error.cause.message;
- errorCauseStack.innerText = error.cause.stack;
- errorCause.classList.remove('hidden');
- } else {
- errorCause.classList.add('hidden');
- }
- // Display the close button, if dismissible
- if (dismissable) {
- errorNotDismissible.classList.add('hidden');
- errorClose.classList.remove("hidden");
- } else {
- errorNotDismissible.classList.remove('hidden');
- errorClose.classList.add("hidden");
+ static getDerivedStateFromError(error) {
+ return { hasError: true };
}
-
- // Show the dialog
- errorDialog.classList.remove("hidden");
-}
-
-export function reportCaughtError({error, cause, componentStack}) {
- reportError({ title: "Caught Error", error, componentStack, dismissable: true});
-}
-export function reportUncaughtError({error, cause, componentStack}) {
- reportError({ title: "Uncaught Error", error, componentStack, dismissable: false });
-}
-
-export function reportRecoverableError({error, cause, componentStack}) {
- reportError({ title: "Recoverable Error", error, componentStack, dismissable: true });
-}
-```
-
-```js src/index.js active
-import { hydrateRoot } from "react-dom/client";
-import App from "./App.js";
-import {reportCaughtError} from "./reportError";
-import "./styles.css";
-
-const container = document.getElementById("root");
-const root = hydrateRoot(container, , {
- onCaughtError: (error, errorInfo) => {
- if (error.message !== 'Known error') {
- reportCaughtError({
- error,
- componentStack: errorInfo.componentStack
- });
+ render() {
+ if (this.state.hasError) {
+ return Something went wrong.
;
}
+ return this.props.children;
}
-});
-```
-
-```js src/App.js
-import { useState } from 'react';
-import { ErrorBoundary } from "react-error-boundary";
+}
export default function App() {
- const [error, setError] = useState(null);
-
- function handleUnknown() {
- setError("unknown");
- }
+ const [triggerUncaughtError, settriggerUncaughtError] = useState(false);
+ const [triggerCaughtError, setTriggerCaughtError] = useState(false);
- function handleKnown() {
- setError("known");
- }
-
return (
<>
- {
- setError(null);
- }}
- >
- {error != null && }
- This error will not show the error dialog:
-
- This error will show the error dialog:
-
-
-
+
+ {triggerUncaughtError && }
+
+ {triggerCaughtError && (
+
+
+
+ )}
);
}
-
-function fallbackRender({ resetErrorBoundary }) {
- return (
-
-
Error Boundary
-
Something went wrong.
-
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
Server
+Server content before hydration.
```
-
-```css src/styles.css active
-label, button { display: block; margin-bottom: 20px; }
-html, body { min-height: 300px; }
-
-#error-dialog {
- position: absolute;
- top: 0;
- right: 0;
- bottom: 0;
- left: 0;
- background-color: white;
- padding: 15px;
- opacity: 0.9;
- text-wrap: wrap;
- overflow: scroll;
-}
-
-.text-red {
- color: red;
-}
-
-.-mb-20 {
- margin-bottom: -20px;
-}
-
-.mb-0 {
- margin-bottom: 0;
-}
-
-.mb-10 {
- margin-bottom: 10px;
-}
-
-pre {
- text-wrap: wrap;
-}
-
-pre.nowrap {
- text-wrap: nowrap;
-}
-
-.hidden {
- display: none;
-}
-```
-
-```js src/reportError.js hidden
-function reportError({ title, error, componentStack, dismissable }) {
- const errorDialog = document.getElementById("error-dialog");
- const errorTitle = document.getElementById("error-title");
- const errorMessage = document.getElementById("error-message");
- const errorBody = document.getElementById("error-body");
- const errorComponentStack = document.getElementById("error-component-stack");
- const errorStack = document.getElementById("error-stack");
- const errorClose = document.getElementById("error-close");
- const errorCause = document.getElementById("error-cause");
- const errorCauseMessage = document.getElementById("error-cause-message");
- const errorCauseStack = document.getElementById("error-cause-stack");
- const errorNotDismissible = document.getElementById("error-not-dismissible");
-
- // Set the title
- errorTitle.innerText = title;
-
- // Display error message and body
- const [heading, body] = error.message.split(/\n(.*)/s);
- errorMessage.innerText = heading;
- if (body) {
- errorBody.innerText = body;
- } else {
- errorBody.innerText = '';
- }
-
- // Display component stack
- errorComponentStack.innerText = componentStack;
-
- // Display the call stack
- // Since we already displayed the message, strip it, and the first Error: line.
- errorStack.innerText = error.stack.replace(error.message, '').split(/\n(.*)/s)[1];
-
- // Display the cause, if available
- if (error.cause) {
- errorCauseMessage.innerText = error.cause.message;
- errorCauseStack.innerText = error.cause.stack;
- errorCause.classList.remove('hidden');
- } else {
- errorCause.classList.add('hidden');
- }
- // Display the close button, if dismissible
- if (dismissable) {
- errorNotDismissible.classList.add('hidden');
- errorClose.classList.remove("hidden");
- } else {
- errorNotDismissible.classList.remove('hidden');
- errorClose.classList.add("hidden");
- }
-
- // Show the dialog
- errorDialog.classList.remove("hidden");
-}
-
-export function reportCaughtError({error, cause, componentStack}) {
- reportError({ title: "Caught Error", error, componentStack, dismissable: true});
-}
-
-export function reportUncaughtError({error, cause, componentStack}) {
- reportError({ title: "Uncaught Error", error, componentStack, dismissable: false });
-}
-
-export function reportRecoverableError({error, cause, componentStack}) {
- reportError({ title: "Recoverable Error", error, componentStack, dismissable: true });
-}
-```
-
-```js src/index.js active
-import { hydrateRoot } from "react-dom/client";
-import App from "./App.js";
-import {reportRecoverableError} from "./reportError";
-import "./styles.css";
-
-const container = document.getElementById("root");
-const root = hydrateRoot(container, , {
- onRecoverableError: (error, errorInfo) => {
- reportRecoverableError({
- error,
- cause: error.cause,
- componentStack: errorInfo.componentStack
- });
- }
-});
-```
-
-```js src/App.js
-import { useState } from 'react';
-import { ErrorBoundary } from "react-error-boundary";
-
-export default function App() {
- const [error, setError] = useState(null);
-
- function handleUnknown() {
- setError("unknown");
- }
-
- function handleKnown() {
- setError("known");
- }
-
- return (
- {typeof window !== 'undefined' ? 'Client' : 'Server'}
- );
-}
-
-function fallbackRender({ resetErrorBoundary }) {
- return (
-
-
Error Boundary
-
Something went wrong.
-
-