`.
- 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.
@@ -1049,7 +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`.
@@ -1134,18 +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/react-compiler.md b/src/content/learn/react-compiler.md
index 0ae499472..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*/}
diff --git a/src/content/learn/react-developer-tools.md b/src/content/learn/react-developer-tools.md
index ef8dbc9b4..ca2b9c981 100644
--- a/src/content/learn/react-developer-tools.md
+++ b/src/content/learn/react-developer-tools.md
@@ -60,7 +60,11 @@ Na koniec odśwież stronę w przeglądarce, aby podejrzeć ją w narzędziach d
## Aplikacje mobilne (React Native) {/*mobile-react-native*/}
+<<<<<<< HEAD
Do inspekcji aplikacji zbudowanych w [React Native](https://reactnative.dev/) możesz wykorzystać [React Native DevTools](https://reactnative.dev/docs/debugging/react-native-devtools), czyli wbudowany debugger głęboko zintegrowany z React Developer Tools. Wszystkie funkcje w nim działają identycznie jak w przypadku rozszerzenia przeglądarkowego, wliczając w to podświetlanie i zaznaczanie natywnych elementów.
+=======
+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.
+>>>>>>> fc29603434ec04621139738f4740caed89d659a7
[Dowiedz się więcej o debuggowaniu w 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 74238163c..e3a4c2632 100644
--- a/src/content/learn/render-and-commit.md
+++ b/src/content/learn/render-and-commit.md
@@ -70,9 +70,15 @@ Spróbuj zakomentować wywołanie `root.render()` i zauważ, że komponent znika
Po początkowym renderowaniu komponentu, możesz wywołać kolejne przerenderowania poprzez aktualizację jego stanu za pomocą [funkcji `set`](/reference/react/useState#setstate). Aktualizacja stanu komponentu automatycznie dodaje renderowanie do kolejki. (Możesz to sobie wyobrazić jako gościa restauracji zamawiającego herbatę, deser i wszelkiego rodzaju rzeczy już po złożeniu pierwszego zamówienia, w zależności od stanu jego pragnienia lub głodu.)
+<<<<<<< HEAD
+=======
+
+
+
+>>>>>>> fc29603434ec04621139738f4740caed89d659a7
## Krok 2: React renderuje twoje komponenty {/*step-2-react-renders-your-components*/}
@@ -84,7 +90,11 @@ Po wywołaniu renderowania, React wywołuje twoje komponenty, aby ustalić, co w
Proces ten jest rekurencyjny: jeśli zaktualizowany komponent zwraca inny komponent, React następnie wyrenderuje _ten_ komponent, a jeśli ten komponent również coś zwraca, wyrenderuje _ten_ komponent, i tak dalej. Proces będzie kontynuowany, aż nie będzie więcej zagnieżdżonych komponentów i React będzie dokładnie wiedział, co powinno być wyświetlane na ekranie.
+<<<<<<< HEAD
W poniższym przykładzie React wywoła `Gallery()` i `Image()` kilkukrotnie:
+=======
+In the following example, React will call `Gallery()` and `Image()` several times:
+>>>>>>> fc29603434ec04621139738f4740caed89d659a7
@@ -148,10 +158,17 @@ Domyślne zachowanie polegające na renderowaniu wszystkich komponentów zagnie
## Krok 3: React aktualizuje zmiany w drzewie DOM {/*step-3-react-commits-changes-to-the-dom*/}
+<<<<<<< HEAD
Po wyrenderowaniu (wywołaniu) twoich komponentów, React zmodyfikuje drzewo DOM.
* **Podczas początkowego renderowania,** React użyje API drzewa DOM o nazwie [`appendChild()`](https://developer.mozilla.org/docs/Web/API/Node/appendChild), aby umieścić na ekranie wszystkie węzły drzewa DOM, które utworzył.
* **Podczas przerenderowań,** React zastosuje minimum niezbędnych operacji (obliczonych podczas renderowania!), aby dopasować drzewo DOM do wyniku najnowszego renderowania.
+=======
+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 re-renders,** React will apply the minimal necessary operations (calculated while rendering!) to make the DOM match the latest rendering output.
+>>>>>>> fc29603434ec04621139738f4740caed89d659a7
**React zmienia węzły drzewa DOM tylko wtedy, gdy występuje różnica pomiędzy renderowaniami.** Na przykład, oto komponent, który przerenderowuje się co sekundę z różnymi właściwościami przekazywanymi z jego rodzica. Zauważ, że możesz dodać tekst do elementu ``, aktualizując jego atrybut `value`, ale tekst nie znika, gdy komponent renderuje się ponownie:
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/state-a-components-memory.md b/src/content/learn/state-a-components-memory.md
index 0d2942f34..5a988d421 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.
-
-
-
-
-
-```
-
-```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
+```js [[1, 6, "onCaughtError"], [2, 6, "error", 1], [3, 6, "errorInfo"], [4, 10, "componentStack", 15]]
import { createRoot } from "react-dom/client";
-import App from "./App.js";
-import {reportUncaughtError} from "./reportError";
-import "./styles.css";
+import { reportCaughtError } from "./reportError";
const container = document.getElementById("root");
const root = createRoot(container, {
- onUncaughtError: (error, errorInfo) => {
- if (error.message !== 'Known error') {
- reportUncaughtError({
+ onCaughtError: (error, errorInfo) => {
+ if (error.message !== "Known error") {
+ reportCaughtError({
error,
- componentStack: errorInfo.componentStack
+ componentStack: errorInfo.componentStack,
});
}
- }
+ },
});
-root.render();
-```
-
-```js src/App.js
-import { useState } from 'react';
-
-export default function App() {
- const [throwError, setThrowError] = useState(false);
-
- if (throwError) {
- foo.bar = 'baz';
- }
-
- return (
-
- 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.
-
-
-
-
-
-```
-
-```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;
+```js src/reportError.js
+function reportError({ type, error, errorInfo }) {
+ // The specific implementation is up to you.
+ // `console.error()` is only used for demonstration purposes.
+ console.error(type, error, "Component Stack: ");
+ console.error("Component Stack: ", errorInfo.componentStack);
}
-.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 = '';
+export function onCaughtErrorProd(error, errorInfo) {
+ if (error.message !== "Known error") {
+ reportError({ type: "Caught", error, errorInfo });
}
-
- // 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 onUncaughtErrorProd(error, errorInfo) {
+ reportError({ type: "Uncaught", error, errorInfo });
}
-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 });
+export function onRecoverableErrorProd(error, errorInfo) {
+ reportError({ type: "Recoverable", error, errorInfo });
}
```
```js src/index.js active
import { createRoot } from "react-dom/client";
import App from "./App.js";
-import {reportCaughtError} from "./reportError";
-import "./styles.css";
+import {
+ onCaughtErrorProd,
+ onRecoverableErrorProd,
+ onUncaughtErrorProd,
+} from "./reportError";
const container = document.getElementById("root");
const root = createRoot(container, {
- onCaughtError: (error, errorInfo) => {
- if (error.message !== 'Known error') {
- reportCaughtError({
- error,
- componentStack: errorInfo.componentStack,
- });
- }
- }
+ // Keep in mind to remove these options in development to leverage
+ // React's default handlers or implement your own overlay for development.
+ // The handlers are only specfied unconditionally here for demonstration purposes.
+ onCaughtError: onCaughtErrorProd,
+ onRecoverableError: onRecoverableErrorProd,
+ onUncaughtError: onUncaughtErrorProd,
});
root.render();
```
```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");
- }
+import { Component, useState } from "react";
- function handleKnown() {
- setError("known");
- }
-
- return (
- <>
- {
- setError(null);
- }}
- >
- {error != null && }
- This error will not show the error dialog:
-
- This error will show the error dialog:
-
-
-
- >
- );
+function Boom() {
+ foo.bar = "baz";
}
-function fallbackRender({ resetErrorBoundary }) {
- return (
-
-
Error Boundary
-
Something went wrong.
-
-
- );
-}
+class ErrorBoundary extends Component {
+ state = { hasError: false };
-function Throw({error}) {
- if (error === "known") {
- throw new Error('Known error')
- } else {
- foo.bar = 'baz';
+ static getDerivedStateFromError(error) {
+ return { hasError: true };
}
-}
-```
-
-```json package.json hidden
-{
- "dependencies": {
- "react": "19.0.0-rc-3edc000d-20240926",
- "react-dom": "19.0.0-rc-3edc000d-20240926",
- "react-scripts": "^5.0.0",
- "react-error-boundary": "4.0.3"
- },
- "main": "/index.js"
-}
-```
-
-
-
-### Displaying a dialog for recoverable errors {/*displaying-a-dialog-for-recoverable-errors*/}
-
-React may automatically render a component a second time to attempt to recover from an error thrown in render. If successful, React will log a recoverable error to the console to notify the developer. To override this behavior, you can provide the optional `onRecoverableError` root option:
-
-```js [[1, 6, "onRecoverableError"], [2, 6, "error", 1], [3, 10, "error.cause"], [4, 6, "errorInfo"], [5, 11, "componentStack"]]
-import { createRoot } from 'react-dom/client';
-const root = createRoot(
- document.getElementById('root'),
- {
- onRecoverableError: (error, errorInfo) => {
- console.error(
- 'Recoverable error',
- error,
- error.cause,
- errorInfo.componentStack,
- );
+ render() {
+ if (this.state.hasError) {
+ return 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.
-
-
-
-
-
-```
-
-```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 { createRoot } from "react-dom/client";
-import App from "./App.js";
-import {reportRecoverableError} from "./reportError";
-import "./styles.css";
-
-const container = document.getElementById("root");
-const root = createRoot(container, {
- onRecoverableError: (error, errorInfo) => {
- reportRecoverableError({
- error,
- cause: error.cause,
- componentStack: errorInfo.componentStack,
- });
- }
-});
-root.render();
-```
-
-```js src/App.js
-import { useState } from 'react';
-import { ErrorBoundary } from "react-error-boundary";
-
-// 🚩 Bug: Never do this. This will force an error.
-let errorThrown = false;
export default function App() {
+ const [triggerUncaughtError, settriggerUncaughtError] = useState(false);
+ const [triggerCaughtError, setTriggerCaughtError] = useState(false);
+
return (
<>
-
- {!errorThrown && }
- 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.
-
- );
-}
-
-function Throw({error}) {
- // Simulate an external value changing during concurrent render.
- errorThrown = true;
- foo.bar = 'baz';
-}
-```
-
-```json package.json hidden
-{
- "dependencies": {
- "react": "19.0.0-rc-3edc000d-20240926",
- "react-dom": "19.0.0-rc-3edc000d-20240926",
- "react-scripts": "^5.0.0",
- "react-error-boundary": "4.0.3"
- },
- "main": "/index.js"
-}
```
-
----
## Troubleshooting {/*troubleshooting*/}
### I've created a root, but nothing is displayed {/*ive-created-a-root-but-nothing-is-displayed*/}
diff --git a/src/content/reference/react-dom/client/hydrateRoot.md b/src/content/reference/react-dom/client/hydrateRoot.md
index c54b6fe11..ca4708845 100644
--- a/src/content/reference/react-dom/client/hydrateRoot.md
+++ b/src/content/reference/react-dom/client/hydrateRoot.md
@@ -374,555 +374,125 @@ export default function App({counter}) {
It is uncommon to call [`root.render`](#root-render) on a hydrated root. Usually, you'll [update state](/reference/react/useState) inside one of the components instead.
-### Show a dialog for uncaught errors {/*show-a-dialog-for-uncaught-errors*/}
+### Error logging in production {/*error-logging-in-production*/}
-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:
+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`:
-```js [[1, 7, "onUncaughtError"], [2, 7, "error", 1], [3, 7, "errorInfo"], [4, 11, "componentStack"]]
-import { hydrateRoot } from 'react-dom/client';
+```js [[1, 6, "onCaughtError"], [2, 6, "error", 1], [3, 6, "errorInfo"], [4, 10, "componentStack", 15]]
+import { hydrateRoot } from "react-dom/client";
+import { reportCaughtError } from "./reportError";
-const root = hydrateRoot(
- document.getElementById('root'),
- ,
- {
- onUncaughtError: (error, errorInfo) => {
- console.error(
- 'Uncaught error',
+const container = document.getElementById("root");
+const root = hydrateRoot(container, {
+ onCaughtError: (error, errorInfo) => {
+ if (error.message !== "Known error") {
+ reportCaughtError({
error,
- errorInfo.componentStack
- );
+ componentStack: errorInfo.componentStack,
+ });
}
- }
-);
-root.render();
+ },
+});
```
-The onUncaughtError option is a function called with two arguments:
+The onCaughtError 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.
-You can use the `onUncaughtError` root option to display error dialogs:
+Together with `onUncaughtError` and `onRecoverableError`, you can implement your own error reporting system:
-```html index.html hidden
-
-
-
- My app
-
-
-
-
-
-
-
-
-
-
-
-
This error occurred at:
-
-
Call stack:
-
-
-
-
This error is not dismissible.
-
-
-This error shows 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;
+```js src/reportError.js
+function reportError({ type, error, errorInfo }) {
+ // The specific implementation is up to you.
+ // `console.error()` is only used for demonstration purposes.
+ console.error(type, error, "Component Stack: ");
+ console.error("Component Stack: ", errorInfo.componentStack);
}
-.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");
+export function onCaughtErrorProd(error, errorInfo) {
+ if (error.message !== "Known error") {
+ reportError({ type: "Caught", error, errorInfo });
}
-
- // 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 onUncaughtErrorProd(error, errorInfo) {
+ reportError({ type: "Uncaught", error, errorInfo });
}
-export function reportRecoverableError({error, cause, componentStack}) {
- reportError({ title: "Recoverable Error", error, componentStack, dismissable: true });
+export function onRecoverableErrorProd(error, errorInfo) {
+ reportError({ type: "Recoverable", error, errorInfo });
}
```
```js src/index.js active
import { hydrateRoot } from "react-dom/client";
import App from "./App.js";
-import {reportUncaughtError} from "./reportError";
-import "./styles.css";
-import {renderToString} from 'react-dom/server';
+import {
+ onCaughtErrorProd,
+ onRecoverableErrorProd,
+ onUncaughtErrorProd,
+} from "./reportError";
const container = document.getElementById("root");
-const root = hydrateRoot(container, , {
- onUncaughtError: (error, errorInfo) => {
- if (error.message !== 'Known error') {
- reportUncaughtError({
- error,
- componentStack: errorInfo.componentStack
- });
- }
- }
+hydrateRoot(container, , {
+ // Keep in mind to remove these options in development to leverage
+ // React's default handlers or implement your own overlay for development.
+ // The handlers are only specfied unconditionally here for demonstration purposes.
+ onCaughtError: onCaughtErrorProd,
+ onRecoverableError: onRecoverableErrorProd,
+ onUncaughtError: onUncaughtErrorProd,
});
```
```js src/App.js
-import { useState } from 'react';
-
-export default function App() {
- const [throwError, setThrowError] = useState(false);
-
- if (throwError) {
- foo.bar = 'baz';
- }
-
- return (
-
- 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.
-
-
- );
-}
-
-function Throw({error}) {
- if (error === "known") {
- throw new Error('Known error')
- } else {
- foo.bar = 'baz';
- }
-}
```
-```json package.json hidden
-{
- "dependencies": {
- "react": "19.0.0-rc-3edc000d-20240926",
- "react-dom": "19.0.0-rc-3edc000d-20240926",
- "react-scripts": "^5.0.0",
- "react-error-boundary": "4.0.3"
- },
- "main": "/index.js"
-}
-```
-
-
-
-### Show a dialog for recoverable hydration mismatch errors {/*show-a-dialog-for-recoverable-hydration-mismatch-errors*/}
-
-When React encounters a hydration mismatch, it will automatically attempt to recover by rendering on the client. By default, React will log hydration mismatch errors to `console.error`. To override this behavior, you can provide the optional `onRecoverableError` root option:
-
-```js [[1, 7, "onRecoverableError"], [2, 7, "error", 1], [3, 11, "error.cause", 1], [4, 7, "errorInfo"], [5, 12, "componentStack"]]
-import { hydrateRoot } from 'react-dom/client';
-
-const root = hydrateRoot(
- document.getElementById('root'),
- ,
- {
- onRecoverableError: (error, errorInfo) => {
- console.error(
- 'Caught error',
- error,
- error.cause,
- errorInfo.componentStack
- );
- }
- }
-);
-```
-
-The onRecoverableError option is a function called with two arguments:
-
-1. The error 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 for hydration mismatches:
-
-
-
-```html index.html hidden
+```html public/index.html hidden
@@ -930,226 +500,12 @@ You can use the `onRecoverableError` root option to display error dialogs for hy
-
-
-
-
-
-
-
-
-
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.
-
-
- );
-}
-
-function Throw({error}) {
- if (error === "known") {
- throw new Error('Known error')
- } else {
- foo.bar = 'baz';
- }
-}
-```
-
-```json package.json hidden
-{
- "dependencies": {
- "react": "19.0.0-rc-3edc000d-20240926",
- "react-dom": "19.0.0-rc-3edc000d-20240926",
- "react-scripts": "^5.0.0",
- "react-error-boundary": "4.0.3"
- },
- "main": "/index.js"
-}
-```
-
## Troubleshooting {/*troubleshooting*/}
diff --git a/src/content/reference/react-dom/components/form.md b/src/content/reference/react-dom/components/form.md
index b3c849e72..115e6a4cd 100644
--- a/src/content/reference/react-dom/components/form.md
+++ b/src/content/reference/react-dom/components/form.md
@@ -214,7 +214,7 @@ export default function App() {
]);
async function sendMessage(formData) {
const sentMessage = await deliverMessage(formData.get("message"));
- setMessages([...messages, { text: sentMessage }]);
+ setMessages((messages) => [...messages, { text: sentMessage }]);
}
return ;
}
diff --git a/src/content/reference/react-dom/components/input.md b/src/content/reference/react-dom/components/input.md
index 9699ce418..b6214249d 100644
--- a/src/content/reference/react-dom/components/input.md
+++ b/src/content/reference/react-dom/components/input.md
@@ -297,7 +297,7 @@ Give a `name` to every ``, for example `
-By default, *any* `