-
+
{isMenuOpen ?
-
-
-
-
-
-
-
- React
-
+
+
+
+
+
+
+
+
+ React
+
+
+
) {
return (
= {};
let content: React.ReactElement[] = [];
Children.forEach(children, (child) => {
- const {props, type} = child;
+ const {props, type} = child as React.ReactElement<{
+ children?: string;
+ id?: string;
+ }>;
switch ((type as any).mdxName) {
case 'Solution': {
challenge.solution = child;
diff --git a/src/components/MDX/Challenges/Navigation.tsx b/src/components/MDX/Challenges/Navigation.tsx
index 736db093c..0511bd05a 100644
--- a/src/components/MDX/Challenges/Navigation.tsx
+++ b/src/components/MDX/Challenges/Navigation.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -108,7 +115,7 @@ export function Navigation({
onClick={handleScrollLeft}
aria-label="Scroll left"
className={cn(
- 'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-l border-gray-20 border-r rtl:rotate-180',
+ 'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-l rtl:rounded-r rtl:rounded-l-none border-gray-20 border-r rtl:border-l rtl:border-r-0',
{
'text-primary dark:text-primary-dark': canScrollLeft,
'text-gray-30': !canScrollLeft,
@@ -120,7 +127,7 @@ export function Navigation({
onClick={handleScrollRight}
aria-label="Scroll right"
className={cn(
- 'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-e rtl:rotate-180',
+ 'bg-secondary-button dark:bg-secondary-button-dark h-8 px-2 rounded-e',
{
'text-primary dark:text-primary-dark': canScrollRight,
'text-gray-30': !canScrollRight,
diff --git a/src/components/MDX/Challenges/index.tsx b/src/components/MDX/Challenges/index.tsx
index 413fd4611..27e3df1ef 100644
--- a/src/components/MDX/Challenges/index.tsx
+++ b/src/components/MDX/Challenges/index.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/CodeBlock/CodeBlock.tsx b/src/components/MDX/CodeBlock/CodeBlock.tsx
index 7eef0abe8..3eeac3945 100644
--- a/src/components/MDX/CodeBlock/CodeBlock.tsx
+++ b/src/components/MDX/CodeBlock/CodeBlock.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -289,7 +296,7 @@ function getSyntaxHighlight(theme: any): HighlightStyle {
function getLineDecorators(
code: string,
- meta: string
+ meta?: string
): Array<{
line: number;
className: string;
@@ -309,7 +316,7 @@ function getLineDecorators(
function getInlineDecorators(
code: string,
- meta: string
+ meta?: string
): Array<{
step: number;
line: number;
@@ -336,6 +343,7 @@ function getInlineDecorators(
line.step === 3,
'bg-green-40 border-green-40 text-green-60 dark:text-green-30':
line.step === 4,
+ // TODO: Some codeblocks use up to 6 steps.
}
),
})
diff --git a/src/components/MDX/CodeBlock/index.tsx b/src/components/MDX/CodeBlock/index.tsx
index 551c1d1b6..d3ed3a065 100644
--- a/src/components/MDX/CodeBlock/index.tsx
+++ b/src/components/MDX/CodeBlock/index.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/CodeDiagram.tsx b/src/components/MDX/CodeDiagram.tsx
index 7a503f068..ba18ae973 100644
--- a/src/components/MDX/CodeDiagram.tsx
+++ b/src/components/MDX/CodeDiagram.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -17,7 +24,14 @@ export function CodeDiagram({children, flip = false}: CodeDiagramProps) {
});
const content = Children.toArray(children).map((child: any) => {
if (child.type?.mdxName === 'pre') {
- return
-
+
+
{text}
diff --git a/src/components/MDX/DiagramGroup.tsx b/src/components/MDX/DiagramGroup.tsx
index 6c5130a3d..8e3bf46c3 100644
--- a/src/components/MDX/DiagramGroup.tsx
+++ b/src/components/MDX/DiagramGroup.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/ErrorDecoder.tsx b/src/components/MDX/ErrorDecoder.tsx
index 198aa939d..423790198 100644
--- a/src/components/MDX/ErrorDecoder.tsx
+++ b/src/components/MDX/ErrorDecoder.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
import {useEffect, useState} from 'react';
import {useErrorDecoderParams} from '../ErrorDecoderContext';
import cn from 'classnames';
@@ -11,7 +18,7 @@ function replaceArgs(
return msg.replace(/%s/g, function () {
const arg = argList[argIdx++];
// arg can be an empty string: ?args[0]=&args[1]=count
- return arg === undefined || arg === '' ? replacer : arg;
+ return arg === undefined ? replacer : arg;
});
}
@@ -69,7 +76,7 @@ function parseQueryString(search: string): Array {
}
export default function ErrorDecoder() {
- const {errorMessage} = useErrorDecoderParams();
+ const {errorMessage, errorCode} = useErrorDecoderParams();
/** error messages that contain %s require reading location.search */
const hasParams = errorMessage?.includes('%s');
const [message, setMessage] = useState(() =>
@@ -82,23 +89,28 @@ export default function ErrorDecoder() {
if (errorMessage == null || !hasParams) {
return;
}
+ const args = parseQueryString(window.location.search);
+ let message = errorMessage;
+ if (errorCode === '418') {
+ // Hydration errors have a %s for the diff, but we don't add that to the args for security reasons.
+ message = message.replace(/%s$/, '');
+
+ // Before React 19.1, the error message didn't have an arg, and was always HTML.
+ if (args.length === 0) {
+ args.push('HTML');
+ } else if (args.length === 1 && args[0] === '') {
+ args[0] = 'HTML';
+ }
+ }
- setMessage(
- urlify(
- replaceArgs(
- errorMessage,
- parseQueryString(window.location.search),
- '[missing argument]'
- )
- )
- );
+ setMessage(urlify(replaceArgs(message, args, '[missing argument]')));
setIsReady(true);
- }, [hasParams, errorMessage]);
+ }, [errorCode, hasParams, errorMessage]);
return (
{message}
diff --git a/src/components/MDX/ExpandableCallout.tsx b/src/components/MDX/ExpandableCallout.tsx
index 415d5d867..ba93d3e27 100644
--- a/src/components/MDX/ExpandableCallout.tsx
+++ b/src/components/MDX/ExpandableCallout.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -8,8 +15,17 @@ import {IconNote} from '../Icon/IconNote';
import {IconWarning} from '../Icon/IconWarning';
import {IconPitfall} from '../Icon/IconPitfall';
import {IconCanary} from '../Icon/IconCanary';
+import {IconRocket} from '../Icon/IconRocket';
-type CalloutVariants = 'deprecated' | 'pitfall' | 'note' | 'wip' | 'canary';
+type CalloutVariants =
+ | 'deprecated'
+ | 'pitfall'
+ | 'note'
+ | 'wip'
+ | 'canary'
+ | 'experimental'
+ | 'major'
+ | 'rsc';
interface ExpandableCalloutProps {
children: React.ReactNode;
@@ -43,6 +59,15 @@ const variantMap = {
overlayGradient:
'linear-gradient(rgba(245, 249, 248, 0), rgba(245, 249, 248, 1)',
},
+ experimental: {
+ title: 'Experimental Feature',
+ Icon: IconCanary,
+ containerClasses:
+ 'bg-green-5 dark:bg-green-60 dark:bg-opacity-20 text-primary dark:text-primary-dark text-lg',
+ textColor: 'text-green-60 dark:text-green-40',
+ overlayGradient:
+ 'linear-gradient(rgba(245, 249, 248, 0), rgba(245, 249, 248, 1)',
+ },
pitfall: {
title: 'Pitfall',
Icon: IconPitfall,
@@ -59,6 +84,22 @@ const variantMap = {
overlayGradient:
'linear-gradient(rgba(249, 247, 243, 0), rgba(249, 247, 243, 1)',
},
+ major: {
+ title: 'React 19',
+ Icon: IconRocket,
+ containerClasses: 'bg-blue-10 dark:bg-blue-60 dark:bg-opacity-20',
+ textColor: 'text-blue-50 dark:text-blue-40',
+ overlayGradient:
+ 'linear-gradient(rgba(249, 247, 243, 0), rgba(249, 247, 243, 1)',
+ },
+ rsc: {
+ title: 'React Server Components',
+ Icon: null,
+ containerClasses: 'bg-blue-10 dark:bg-blue-60 dark:bg-opacity-20',
+ textColor: 'text-blue-50 dark:text-blue-40',
+ overlayGradient:
+ 'linear-gradient(rgba(249, 247, 243, 0), rgba(249, 247, 243, 1)',
+ },
};
function ExpandableCallout({children, type = 'note'}: ExpandableCalloutProps) {
@@ -72,9 +113,11 @@ function ExpandableCallout({children, type = 'note'}: ExpandableCalloutProps) {
variant.containerClasses
)}>
-
diff --git a/src/components/MDX/ExpandableExample.tsx b/src/components/MDX/ExpandableExample.tsx
index 1e709e483..c11cd6c3c 100644
--- a/src/components/MDX/ExpandableExample.tsx
+++ b/src/components/MDX/ExpandableExample.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Heading.tsx b/src/components/MDX/Heading.tsx
index a9f3efc38..5890a3a48 100644
--- a/src/components/MDX/Heading.tsx
+++ b/src/components/MDX/Heading.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/InlineCode.tsx b/src/components/MDX/InlineCode.tsx
index 0e8db0165..17e4683b9 100644
--- a/src/components/MDX/InlineCode.tsx
+++ b/src/components/MDX/InlineCode.tsx
@@ -1,8 +1,16 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
import cn from 'classnames';
+import type {HTMLAttributes} from 'react';
interface InlineCodeProps {
isLink?: boolean;
@@ -11,7 +19,7 @@ interface InlineCodeProps {
function InlineCode({
isLink,
...props
-}: JSX.IntrinsicElements['code'] & InlineCodeProps) {
+}: HTMLAttributes
& InlineCodeProps) {
return (
in case of RTL languages to avoid like `()console.log` to be rendered as `console.log()`
diff --git a/src/components/MDX/Intro.tsx b/src/components/MDX/Intro.tsx
index 0522df678..b0bee624d 100644
--- a/src/components/MDX/Intro.tsx
+++ b/src/components/MDX/Intro.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/LanguagesContext.tsx b/src/components/MDX/LanguagesContext.tsx
index 776a11c0d..cd9f88816 100644
--- a/src/components/MDX/LanguagesContext.tsx
+++ b/src/components/MDX/LanguagesContext.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Link.tsx b/src/components/MDX/Link.tsx
index 7bf041e56..8a47c401f 100644
--- a/src/components/MDX/Link.tsx
+++ b/src/components/MDX/Link.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/MDXComponents.tsx b/src/components/MDX/MDXComponents.tsx
index 6f99121f7..7a258370c 100644
--- a/src/components/MDX/MDXComponents.tsx
+++ b/src/components/MDX/MDXComponents.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -5,6 +12,7 @@
import {Children, useContext, useMemo} from 'react';
import * as React from 'react';
import cn from 'classnames';
+import type {HTMLAttributes} from 'react';
import CodeBlock from './CodeBlock';
import {CodeDiagram} from './CodeDiagram';
@@ -36,6 +44,7 @@ import {finishedTranslations} from 'utils/finishedTranslations';
import ErrorDecoder from './ErrorDecoder';
import {IconCanary} from '../Icon/IconCanary';
+import {IconExperimental} from 'components/Icon/IconExperimental';
function CodeStep({children, step}: {children: any; step: number}) {
return (
@@ -59,21 +68,21 @@ function CodeStep({children, step}: {children: any; step: number}) {
);
}
-const P = (p: JSX.IntrinsicElements['p']) => (
+const P = (p: HTMLAttributes) => (
);
-const Strong = (strong: JSX.IntrinsicElements['strong']) => (
+const Strong = (strong: HTMLAttributes) => (
) => (
) => (
) => (
);
@@ -97,6 +106,18 @@ const Canary = ({children}: {children: React.ReactNode}) => (
{children}
);
+const Experimental = ({children}: {children: React.ReactNode}) => (
+ {children}
+);
+
+const NextMajor = ({children}: {children: React.ReactNode}) => (
+ {children}
+);
+
+const RSC = ({children}: {children: React.ReactNode}) => (
+ {children}
+);
+
const CanaryBadge = ({title}: {title: string}) => (
(
);
-const Blockquote = ({
- children,
- ...props
-}: JSX.IntrinsicElements['blockquote']) => {
+const ExperimentalBadge = ({title}: {title: string}) => (
+
+
+);
+
+const NextMajorBadge = ({title}: {title: string}) => (
+
+ React 19
+
+);
+
+const RSCBadge = ({title}: {title: string}) => (
+
+ RSC
+
+);
+
+const Blockquote = ({children, ...props}: HTMLAttributes) => {
return (
));
return (
-
+
{sequential ? (
@@ -325,7 +377,7 @@ function IllustrationBlock({
)}
+
);
}
@@ -482,7 +534,13 @@ export const MDXComponents = {
MathI,
Note,
Canary,
+ Experimental,
+ ExperimentalBadge,
CanaryBadge,
+ NextMajor,
+ NextMajorBadge,
+ RSC,
+ RSCBadge,
PackageImport,
ReadBlogPost,
Recap,
diff --git a/src/components/MDX/PackageImport.tsx b/src/components/MDX/PackageImport.tsx
index 5e2da820e..222353ff5 100644
--- a/src/components/MDX/PackageImport.tsx
+++ b/src/components/MDX/PackageImport.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Recap.tsx b/src/components/MDX/Recap.tsx
index d91ed48b4..293304367 100644
--- a/src/components/MDX/Recap.tsx
+++ b/src/components/MDX/Recap.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Sandpack/ClearButton.tsx b/src/components/MDX/Sandpack/ClearButton.tsx
new file mode 100644
index 000000000..be7451ab3
--- /dev/null
+++ b/src/components/MDX/Sandpack/ClearButton.tsx
@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ */
+
+import * as React from 'react';
+import {IconClose} from '../../Icon/IconClose';
+export interface ClearButtonProps {
+ onClear: () => void;
+}
+
+export function ClearButton({onClear}: ClearButtonProps) {
+ return (
+
+ Clear
+
+ );
+}
diff --git a/src/components/MDX/Sandpack/Console.tsx b/src/components/MDX/Sandpack/Console.tsx
index b5276fc13..3417e11f1 100644
--- a/src/components/MDX/Sandpack/Console.tsx
+++ b/src/components/MDX/Sandpack/Console.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Sandpack/CustomPreset.tsx b/src/components/MDX/Sandpack/CustomPreset.tsx
index c133e2a83..4a241c87c 100644
--- a/src/components/MDX/Sandpack/CustomPreset.tsx
+++ b/src/components/MDX/Sandpack/CustomPreset.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -28,6 +35,7 @@ export const CustomPreset = memo(function CustomPreset({
const {activeFile} = sandpack;
const lineCountRef = useRef<{[key: string]: number}>({});
if (!lineCountRef.current[activeFile]) {
+ // eslint-disable-next-line react-compiler/react-compiler
lineCountRef.current[activeFile] = code.split('\n').length;
}
const lineCount = lineCountRef.current[activeFile];
diff --git a/src/components/MDX/Sandpack/DownloadButton.tsx b/src/components/MDX/Sandpack/DownloadButton.tsx
index 94cf13ddc..b51627d89 100644
--- a/src/components/MDX/Sandpack/DownloadButton.tsx
+++ b/src/components/MDX/Sandpack/DownloadButton.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Sandpack/ErrorMessage.tsx b/src/components/MDX/Sandpack/ErrorMessage.tsx
index 7c67ee461..3dbeb113b 100644
--- a/src/components/MDX/Sandpack/ErrorMessage.tsx
+++ b/src/components/MDX/Sandpack/ErrorMessage.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Sandpack/LoadingOverlay.tsx b/src/components/MDX/Sandpack/LoadingOverlay.tsx
index cd3f38fca..1945f0c6f 100644
--- a/src/components/MDX/Sandpack/LoadingOverlay.tsx
+++ b/src/components/MDX/Sandpack/LoadingOverlay.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
import {useState} from 'react';
import {
@@ -17,7 +24,7 @@ export const LoadingOverlay = ({
clientId: string;
dependenciesLoading: boolean;
forceLoading: boolean;
-} & React.HTMLAttributes): JSX.Element | null => {
+} & React.HTMLAttributes): React.ReactNode | null => {
const loadingOverlayState = useLoadingOverlayState(
clientId,
dependenciesLoading,
@@ -64,6 +71,7 @@ export const LoadingOverlay = ({
transition: `opacity ${FADE_ANIMATION_DURATION}ms ease-out`,
}}>
+ {/* @ts-ignore: the OpenInCodeSandboxButton type from '@codesandbox/sandpack-react/unstyled' is incompatible with JSX in React 19 */}
diff --git a/src/components/MDX/Sandpack/NavigationBar.tsx b/src/components/MDX/Sandpack/NavigationBar.tsx
index 26ed5783d..3fe743a2d 100644
--- a/src/components/MDX/Sandpack/NavigationBar.tsx
+++ b/src/components/MDX/Sandpack/NavigationBar.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -17,7 +24,8 @@ import {
useSandpackNavigation,
} from '@codesandbox/sandpack-react/unstyled';
import {OpenInCodeSandboxButton} from './OpenInCodeSandboxButton';
-import {ResetButton} from './ResetButton';
+import {ReloadButton} from './ReloadButton';
+import {ClearButton} from './ClearButton';
import {DownloadButton} from './DownloadButton';
import {IconChevron} from '../../Icon/IconChevron';
import {Listbox} from '@headlessui/react';
@@ -95,7 +103,7 @@ export function NavigationBar({providedFiles}: {providedFiles: Array
}) {
// Note: in a real useEvent, onContainerResize would be omitted.
}, [isMultiFile, onContainerResize]);
- const handleReset = () => {
+ const handleClear = () => {
/**
* resetAllFiles must come first, otherwise
* the previous content will appear for a second
@@ -103,19 +111,22 @@ export function NavigationBar({providedFiles}: {providedFiles: Array}) {
*
* Plus, it should only prompt if there's any file changes
*/
- if (
- sandpack.editorState === 'dirty' &&
- confirm('Reset all your edits too?')
- ) {
+ if (sandpack.editorState === 'dirty' && confirm('Clear all your edits?')) {
sandpack.resetAllFiles();
}
+ refresh();
+ };
+ const handleReload = () => {
refresh();
};
return (
+ {/* If Prettier reformats this block, the two @ts-ignore directives will no longer be adjacent to the problematic lines, causing TypeScript errors */}
+ {/* prettier-ignore */}
+ {/* @ts-ignore: the Listbox type from '@headlessui/react' is incompatible with JSX in React 19 */}
@@ -129,8 +140,10 @@ export function NavigationBar({providedFiles}: {providedFiles: Array}) {
'w-[fit-content]',
showDropdown ? 'invisible' : ''
)}>
+ {/* @ts-ignore: the FileTabs type from '@codesandbox/sandpack-react/unstyled' is incompatible with JSX in React 19 */}
+ {/* @ts-ignore: the Listbox type from '@headlessui/react' is incompatible with JSX in React 19 */}
{({open}) => (
// If tabs don't fit, display the dropdown instead.
@@ -160,10 +173,10 @@ export function NavigationBar({providedFiles}: {providedFiles: Array}) {
- {isMultiFile && showDropdown && (
-
- {visibleFiles.map((filePath: string) => (
-
+ {/* @ts-ignore: the Listbox type from '@headlessui/react' is incompatible with JSX in React 19 */}
+ {isMultiFile && showDropdown && (
+ {/* @ts-ignore: the Listbox type from '@headlessui/react' is incompatible with JSX in React 19 */}
+ {visibleFiles.map((filePath: string) => (
{({active}) => (
}) {
className="px-3 flex items-center justify-end text-start"
translate="yes">
{
setShowLoading(true);
diff --git a/src/components/MDX/Sandpack/ReloadButton.tsx b/src/components/MDX/Sandpack/ReloadButton.tsx
new file mode 100644
index 000000000..71a25ea47
--- /dev/null
+++ b/src/components/MDX/Sandpack/ReloadButton.tsx
@@ -0,0 +1,29 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ */
+
+import * as React from 'react';
+import {IconRestart} from '../../Icon/IconRestart';
+export interface ReloadButtonProps {
+ onReload: () => void;
+}
+
+export function ReloadButton({onReload}: ReloadButtonProps) {
+ return (
+
+ Reload
+
+ );
+}
diff --git a/src/components/MDX/Sandpack/ResetButton.tsx b/src/components/MDX/Sandpack/ResetButton.tsx
deleted file mode 100644
index 0d1e22c80..000000000
--- a/src/components/MDX/Sandpack/ResetButton.tsx
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (c) Facebook, Inc. and its affiliates.
- */
-
-import * as React from 'react';
-import {IconRestart} from '../../Icon/IconRestart';
-export interface ResetButtonProps {
- onReset: () => void;
-}
-
-export function ResetButton({onReset}: ResetButtonProps) {
- return (
-
-
- );
-}
diff --git a/src/components/MDX/Sandpack/SandpackRoot.tsx b/src/components/MDX/Sandpack/SandpackRoot.tsx
index a47fa6860..48d8daee5 100644
--- a/src/components/MDX/Sandpack/SandpackRoot.tsx
+++ b/src/components/MDX/Sandpack/SandpackRoot.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -71,6 +78,13 @@ function SandpackRoot(props: SandpackProps) {
const codeSnippets = Children.toArray(children) as React.ReactElement[];
const files = createFileMap(codeSnippets);
+ if ('/index.html' in files) {
+ throw new Error(
+ 'You cannot use `index.html` file in sandboxes. ' +
+ 'Only `public/index.html` is respected by Sandpack and CodeSandbox (where forks are created).'
+ );
+ }
+
files['/src/styles.css'] = {
code: [sandboxStyle, files['/src/styles.css']?.code ?? ''].join('\n\n'),
hidden: !files['/src/styles.css']?.visible,
diff --git a/src/components/MDX/Sandpack/Themes.tsx b/src/components/MDX/Sandpack/Themes.tsx
index 3923470ca..8aa34dc95 100644
--- a/src/components/MDX/Sandpack/Themes.tsx
+++ b/src/components/MDX/Sandpack/Themes.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Sandpack/createFileMap.ts b/src/components/MDX/Sandpack/createFileMap.ts
index 615d34c9a..049face93 100644
--- a/src/components/MDX/Sandpack/createFileMap.ts
+++ b/src/components/MDX/Sandpack/createFileMap.ts
@@ -1,13 +1,81 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
import type {SandpackFile} from '@codesandbox/sandpack-react/unstyled';
+import type {PropsWithChildren, ReactElement, HTMLAttributes} from 'react';
export const AppJSPath = `/src/App.js`;
export const StylesCSSPath = `/src/styles.css`;
export const SUPPORTED_FILES = [AppJSPath, StylesCSSPath];
+/**
+ * Tokenize meta attributes while ignoring brace-wrapped metadata (e.g. {expectedErrors: …}).
+ */
+function splitMeta(meta: string): string[] {
+ const tokens: string[] = [];
+ let current = '';
+ let depth = 0;
+ const trimmed = meta.trim();
+
+ for (let ii = 0; ii < trimmed.length; ii++) {
+ const char = trimmed[ii];
+
+ if (char === '{') {
+ if (depth === 0 && current) {
+ tokens.push(current);
+ current = '';
+ }
+ depth += 1;
+ continue;
+ }
+
+ if (char === '}') {
+ if (depth > 0) {
+ depth -= 1;
+ }
+ if (depth === 0) {
+ current = '';
+ }
+ if (depth < 0) {
+ throw new Error(`Unexpected closing brace in meta: ${meta}`);
+ }
+ continue;
+ }
+
+ if (depth > 0) {
+ continue;
+ }
+
+ if (/\s/.test(char)) {
+ if (current) {
+ tokens.push(current);
+ current = '';
+ }
+ continue;
+ }
+
+ current += char;
+ }
+
+ if (current) {
+ tokens.push(current);
+ }
+
+ if (depth !== 0) {
+ throw new Error(`Unclosed brace in meta: ${meta}`);
+ }
+
+ return tokens;
+}
+
export const createFileMap = (codeSnippets: any) => {
return codeSnippets.reduce(
(result: Record, codeSnippet: React.ReactElement) => {
@@ -17,18 +85,29 @@ export const createFileMap = (codeSnippets: any) => {
) {
return result;
}
- const {props} = codeSnippet.props.children;
+ const {props} = (
+ codeSnippet.props as PropsWithChildren<{
+ children: ReactElement<
+ HTMLAttributes & {meta?: string}
+ >;
+ }>
+ ).children;
let filePath; // path in the folder structure
let fileHidden = false; // if the file is available as a tab
let fileActive = false; // if the file tab is shown by default
if (props.meta) {
- const [name, ...params] = props.meta.split(' ');
- filePath = '/' + name;
- if (params.includes('hidden')) {
+ const tokens = splitMeta(props.meta);
+ const name = tokens.find(
+ (token) => token.includes('/') || token.includes('.')
+ );
+ if (name) {
+ filePath = name.startsWith('/') ? name : `/${name}`;
+ }
+ if (tokens.includes('hidden')) {
fileHidden = true;
}
- if (params.includes('active')) {
+ if (tokens.includes('active')) {
fileActive = true;
}
} else {
@@ -43,6 +122,18 @@ export const createFileMap = (codeSnippets: any) => {
}
}
+ if (!filePath) {
+ if (props.className === 'language-js') {
+ filePath = AppJSPath;
+ } else if (props.className === 'language-css') {
+ filePath = StylesCSSPath;
+ } else {
+ throw new Error(
+ `Code block is missing a filename: ${props.children}`
+ );
+ }
+ }
+
if (result[filePath]) {
throw new Error(
`File ${filePath} was defined multiple times. Each file snippet should have a unique path name`
diff --git a/src/components/MDX/Sandpack/index.tsx b/src/components/MDX/Sandpack/index.tsx
index 6755ba8de..08e7dd6f0 100644
--- a/src/components/MDX/Sandpack/index.tsx
+++ b/src/components/MDX/Sandpack/index.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/Sandpack/runESLint.tsx b/src/components/MDX/Sandpack/runESLint.tsx
index 5fea2f110..a0b835461 100644
--- a/src/components/MDX/Sandpack/runESLint.tsx
+++ b/src/components/MDX/Sandpack/runESLint.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
// @ts-nocheck
import {Linter} from 'eslint/lib/linter/linter';
diff --git a/src/components/MDX/Sandpack/template.ts b/src/components/MDX/Sandpack/template.ts
index 9ead18a14..358c8616e 100644
--- a/src/components/MDX/Sandpack/template.ts
+++ b/src/components/MDX/Sandpack/template.ts
@@ -1,7 +1,14 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
export const template = {
'/src/index.js': {
hidden: true,
- code: `import React, { StrictMode } from "react";
+ code: `import { StrictMode } from "react";
import { createRoot } from "react-dom/client";
import "./styles.css";
@@ -28,8 +35,8 @@ root.render(
eject: 'react-scripts eject',
},
dependencies: {
- react: '^18.0.0',
- 'react-dom': '^18.0.0',
+ react: '^19.1.0',
+ 'react-dom': '^19.1.0',
'react-scripts': '^5.0.0',
},
},
diff --git a/src/components/MDX/Sandpack/useSandpackLint.tsx b/src/components/MDX/Sandpack/useSandpackLint.tsx
index ec05fbe0d..479b53ee0 100644
--- a/src/components/MDX/Sandpack/useSandpackLint.tsx
+++ b/src/components/MDX/Sandpack/useSandpackLint.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/SandpackWithHTMLOutput.tsx b/src/components/MDX/SandpackWithHTMLOutput.tsx
index 51ce28dc1..c5149deb9 100644
--- a/src/components/MDX/SandpackWithHTMLOutput.tsx
+++ b/src/components/MDX/SandpackWithHTMLOutput.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
import {Children, memo} from 'react';
import InlineCode from './InlineCode';
import Sandpack from './Sandpack';
diff --git a/src/components/MDX/SimpleCallout.tsx b/src/components/MDX/SimpleCallout.tsx
index ae259bcf5..0e124baa7 100644
--- a/src/components/MDX/SimpleCallout.tsx
+++ b/src/components/MDX/SimpleCallout.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/TeamMember.tsx b/src/components/MDX/TeamMember.tsx
index eaf74187e..2d0c65537 100644
--- a/src/components/MDX/TeamMember.tsx
+++ b/src/components/MDX/TeamMember.tsx
@@ -1,11 +1,19 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
import * as React from 'react';
-import Image from 'next/image';
+import Image from 'next/legacy/image';
import {IconTwitter} from '../Icon/IconTwitter';
import {IconThreads} from '../Icon/IconThreads';
+import {IconBsky} from '../Icon/IconBsky';
import {IconGitHub} from '../Icon/IconGitHub';
import {ExternalLink} from '../ExternalLink';
import {H3} from './Heading';
@@ -19,6 +27,7 @@ interface TeamMemberProps {
photo: string;
twitter?: string;
threads?: string;
+ bsky?: string;
github?: string;
personal?: string;
}
@@ -33,14 +42,13 @@ export function TeamMember({
github,
twitter,
threads,
+ bsky,
personal,
}: TeamMemberProps) {
if (name == null || title == null || permalink == null || children == null) {
+ const identifier = name ?? title ?? permalink ?? 'unknown';
throw new Error(
- 'Expected name, title, permalink, and children for ' + name ??
- title ??
- permalink ??
- 'unknown'
+ `Expected name, title, permalink, and children for ${identifier}`
);
}
return (
@@ -62,11 +70,11 @@ export function TeamMember({
{title && {title}
}
{children}
-
+
{twitter && (
)}
+ {bsky && (
+
+
+
+
+ )}
{github && (
).props
+ .children === 'string'
) {
- message = children.props.children;
+ message = (children as React.ReactElement<{children: string}>).props
+ .children;
} else {
throw Error('Expected TerminalBlock children to be a plain string.');
}
@@ -71,7 +80,7 @@ function TerminalBlock({level = 'info', children}: TerminalBlockProps) {
diff --git a/src/components/MDX/TocContext.tsx b/src/components/MDX/TocContext.tsx
index 8aeead370..924e6e09e 100644
--- a/src/components/MDX/TocContext.tsx
+++ b/src/components/MDX/TocContext.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/MDX/YouWillLearnCard.tsx b/src/components/MDX/YouWillLearnCard.tsx
index d46a70277..20fc3b5fe 100644
--- a/src/components/MDX/YouWillLearnCard.tsx
+++ b/src/components/MDX/YouWillLearnCard.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
diff --git a/src/components/PageHeading.tsx b/src/components/PageHeading.tsx
index 659295d0a..760542750 100644
--- a/src/components/PageHeading.tsx
+++ b/src/components/PageHeading.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -8,10 +15,12 @@ import {H1} from './MDX/Heading';
import type {RouteTag, RouteItem} from './Layout/getRouteMeta';
import * as React from 'react';
import {IconCanary} from './Icon/IconCanary';
+import {IconExperimental} from './Icon/IconExperimental';
interface PageHeadingProps {
title: string;
- canary?: boolean;
+ version?: 'experimental' | 'canary';
+ experimental?: boolean;
status?: string;
description?: string;
tags?: RouteTag[];
@@ -21,8 +30,7 @@ interface PageHeadingProps {
function PageHeading({
title,
status,
- canary,
- description,
+ version,
tags = [],
breadcrumbs,
}: PageHeadingProps) {
@@ -32,19 +40,20 @@ function PageHeading({
{breadcrumbs ?
: null}
{title}
- {canary && (
+ {version === 'canary' && (
—{status} : ''}
- {description && (
-
- {description}
-
- )}
{tags?.length > 0 && (
{tags.map((tag) => (
diff --git a/src/components/Search.tsx b/src/components/Search.tsx
index cff7f8852..24b066d70 100644
--- a/src/components/Search.tsx
+++ b/src/components/Search.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -9,6 +16,8 @@ import {lazy, useEffect} from 'react';
import * as React from 'react';
import {createPortal} from 'react-dom';
import {siteConfig} from 'siteConfig';
+import type {ComponentType, PropsWithChildren} from 'react';
+import type {DocSearchModalProps} from '@docsearch/react/modal';
export interface SearchProps {
appId?: string;
@@ -83,9 +92,10 @@ const options = {
};
const DocSearchModal: any = lazy(() =>
- // @ts-ignore
import('@docsearch/react/modal').then((mod) => ({
- default: mod.DocSearchModal,
+ default: mod.DocSearchModal as ComponentType<
+ PropsWithChildren
+ >,
}))
);
@@ -94,7 +104,17 @@ 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});
diff --git a/src/components/Seo.tsx b/src/components/Seo.tsx
index 628085744..906041020 100644
--- a/src/components/Seo.tsx
+++ b/src/components/Seo.tsx
@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
/*
* Copyright (c) Facebook, Inc. and its affiliates.
*/
@@ -124,7 +131,14 @@ export const Seo = withRouter(
)}
- {name} {isPacked ? '✔' : '❌'}
+ {name} {isPacked ? '✅' : '❌'}
);
}
@@ -631,7 +631,7 @@ We think there's never been a better time to learn React.
## Who worked on this? {/*who-worked-on-this*/}
-On the React team, [Rachel Nabors](https://twitter.com/rachelnabors/) led the project (and provided the illustrations), and [Dan Abramov](https://twitter.com/dan_abramov) designed the curriculum. They co-authored most of the content together as well.
+On the React team, [Rachel Nabors](https://twitter.com/rachelnabors/) led the project (and provided the illustrations), and [Dan Abramov](https://bsky.app/profile/danabra.mov) designed the curriculum. They co-authored most of the content together as well.
Of course, no project this large happens in isolation. We have a lot of people to thank!
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 aeb677f31..1bc78149d 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
@@ -97,9 +97,9 @@ The Transition Tracing API lets you detect when [React Transitions](/reference/r
* * *
In addition to this update, our team has made recent guest appearances on community podcasts and livestreams to speak more on our work and answer questions.
-* [Dan Abramov](https://twitter.com/dan_abramov) and [Joe Savona](https://twitter.com/en_JS) were interviewed by [Kent C. Dodds on his YouTube channel](https://www.youtube.com/watch?v=h7tur48JSaw), where they discussed concerns around React Server Components.
-* [Dan Abramov](https://twitter.com/dan_abramov) and [Joe Savona](https://twitter.com/en_JS) were guests on the [JSParty podcast](https://jsparty.fm/267) and shared their thoughts about the future of React.
+* [Dan Abramov](https://bsky.app/profile/danabra.mov) and [Joe Savona](https://twitter.com/en_JS) were interviewed by [Kent C. Dodds on his YouTube channel](https://www.youtube.com/watch?v=h7tur48JSaw), where they discussed concerns around React Server Components.
+* [Dan Abramov](https://bsky.app/profile/danabra.mov) and [Joe Savona](https://twitter.com/en_JS) were guests on the [JSParty podcast](https://jsparty.fm/267) and shared their thoughts about the future of React.
-Thanks to [Andrew Clark](https://twitter.com/acdlite), [Dan Abramov](https://twitter.com/dan_abramov), [Dave McCabe](https://twitter.com/mcc_abe), [Luna Wei](https://twitter.com/lunaleaps), [Matt Carroll](https://twitter.com/mattcarrollcode), [Sean Keegan](https://twitter.com/DevRelSean), [Sebastian Silbermann](https://twitter.com/sebsilbermann), [Seth Webster](https://twitter.com/sethwebster), and [Sophie Alpert](https://twitter.com/sophiebits) for reviewing this post.
+Thanks to [Andrew Clark](https://twitter.com/acdlite), [Dan Abramov](https://bsky.app/profile/danabra.mov), [Dave McCabe](https://twitter.com/mcc_abe), [Luna Wei](https://twitter.com/lunaleaps), [Matt Carroll](https://twitter.com/mattcarrollcode), [Sean Keegan](https://twitter.com/DevRelSean), [Sebastian Silbermann](https://twitter.com/sebsilbermann), [Seth Webster](https://twitter.com/sethwebster), and [Sophie Alpert](https://twitter.com/sophiebits) for reviewing this post.
Thanks for reading, and see you in the next update!
diff --git a/src/content/blog/2023/05/03/react-canaries.md b/src/content/blog/2023/05/03/react-canaries.md
index 19d9960b0..c2e1a823e 100644
--- a/src/content/blog/2023/05/03/react-canaries.md
+++ b/src/content/blog/2023/05/03/react-canaries.md
@@ -5,7 +5,7 @@ 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)
+May 3, 2023 by [Dan Abramov](https://bsky.app/profile/danabra.mov), [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 fee21f4ec..9ec330e6b 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
@@ -5,7 +5,7 @@ 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).
+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://bsky.app/profile/danabra.mov).
---
@@ -107,7 +107,7 @@ Activity is still under research and our remaining work is to finalize the primi
In addition to this update, our team has presented at conferences and made appearances on podcasts to speak more on our work and answer questions.
-- [Sathya Gunasekaran](/community/team#sathya-gunasekaran) spoke about the React Compiler at the [React India](https://www.youtube.com/watch?v=kjOacmVsLSE) conference
+- [Sathya Gunasekaran](https://github.com/gsathya) spoke about the React Compiler at the [React India](https://www.youtube.com/watch?v=kjOacmVsLSE) conference
- [Dan Abramov](/community/team#dan-abramov) gave a talk at [RemixConf](https://www.youtube.com/watch?v=zMf_xeGPn6s) titled “React from Another Dimension” which explores an alternative history of how React Server Components and Actions could have been created
diff --git a/src/content/blog/2024/04/25/react-19-upgrade-guide.md b/src/content/blog/2024/04/25/react-19-upgrade-guide.md
index 4d4355a47..cb83a6176 100644
--- a/src/content/blog/2024/04/25/react-19-upgrade-guide.md
+++ b/src/content/blog/2024/04/25/react-19-upgrade-guide.md
@@ -1,26 +1,18 @@
---
-title: "React 19 Beta Upgrade Guide"
+title: "React 19 Upgrade Guide"
author: Ricky Hanlon
date: 2024/04/25
-description: 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 beta.
+description: 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 apps and libraries to React 19.
---
April 25, 2024 by [Ricky Hanlon](https://twitter.com/rickhanlonii)
---
-
-
-This beta release is for libraries to prepare for React 19. App developers should upgrade to 18.3.0 and wait for React 19 stable as we work with libraries and make changes based on feedback.
-
-
-
-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.
-
-To help make the upgrade easier, today we are also publishing React 18.3.
+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.
@@ -32,20 +24,21 @@ To help make the upgrade to React 19 easier, we've published a `react@18.3` rele
We recommend upgrading to React 18.3 first to help identify any issues before upgrading to React 19.
-For a list of changes in 18.3 see the [Release Notes](https://github.com/facebook/react/blob/main/CHANGELOG.md).
+For a list of changes in 18.3 see the [Release Notes](https://github.com/facebook/react/blob/main/CHANGELOG.md#1830-april-25-2024).
-In this post, we will guide you through the steps for upgrading libraries to React 19 beta:
+In this post, we will guide you through the steps for upgrading to React 19:
- [Installing](#installing)
+- [Codemods](#codemods)
- [Breaking changes](#breaking-changes)
- [New deprecations](#new-deprecations)
- [Notable changes](#notable-changes)
- [TypeScript changes](#typescript-changes)
- [Changelog](#changelog)
-If you'd like to help us test React 19, follow the steps in this upgrade guide and [report any issues](https://github.com/facebook/react/issues/new?assignees=&labels=React+19&projects=&template=19.md&title=%5BReact+19%5D) you encounter. For a list of new features added to React 19 beta, see the [React 19 release post](/blog/2024/04/25/react-19).
+If you'd like to help us test React 19, follow the steps in this upgrade guide and [report any issues](https://github.com/facebook/react/issues/new?assignees=&labels=React+19&projects=&template=19.md&title=%5BReact+19%5D) you encounter. For a list of new features added to React 19, see the [React 19 release post](/blog/2024/12/05/react-19).
---
## Installing {/*installing*/}
@@ -77,26 +70,58 @@ We expect most apps will not be affected since the transform is enabled in most
To install the latest version of React and React DOM:
```bash
-npm install react@beta react-dom@beta
+npm install --save-exact react@^19.0.0 react-dom@^19.0.0
```
-If you're using TypeScript, you also need to update the types. Once React 19 is released as stable, you can install the types as usual from `@types/react` and `@types/react-dom`. During the beta period, the types are available in different packages which need to be enforced in your `package.json`:
+Or, if you're using Yarn:
-```json
-{
- "dependencies": {
- "@types/react": "npm:types-react@beta",
- "@types/react-dom": "npm:types-react-dom@beta"
- },
- "overrides": {
- "@types/react": "npm:types-react@beta",
- "@types/react-dom": "npm:types-react-dom@beta"
- }
-}
+```bash
+yarn add --exact react@^19.0.0 react-dom@^19.0.0
+```
+
+If you're using TypeScript, you also need to update the types.
+```bash
+npm install --save-exact @types/react@^19.0.0 @types/react-dom@^19.0.0
+```
+
+Or, if you're using Yarn:
+```bash
+yarn add --exact @types/react@^19.0.0 @types/react-dom@^19.0.0
```
We're also including a codemod for the most common replacements. See [TypeScript changes](#typescript-changes) below.
+## Codemods {/*codemods*/}
+
+To help with the upgrade, we've worked with the team at [codemod.com](https://codemod.com) to publish codemods that will automatically update your code to many of the new APIs and patterns in React 19.
+
+All codemods are available in the [`react-codemod` repo](https://github.com/reactjs/react-codemod) and the Codemod team have joined in helping maintain the codemods. To run these codemods, we recommend using the `codemod` command instead of the `react-codemod` because it runs faster, handles more complex code migrations, and provides better support for TypeScript.
+
+
+
+
+#### Run all React 19 codemods {/*run-all-react-19-codemods*/}
+
+Run all codemods listed in this guide with the React 19 `codemod` recipe:
+
+```bash
+npx codemod@latest react/19/migration-recipe
+```
+
+This will run the following codemods from `react-codemod`:
+- [`replace-reactdom-render`](https://github.com/reactjs/react-codemod?tab=readme-ov-file#replace-reactdom-render)
+- [`replace-string-ref`](https://github.com/reactjs/react-codemod?tab=readme-ov-file#replace-string-ref)
+- [`replace-act-import`](https://github.com/reactjs/react-codemod?tab=readme-ov-file#replace-act-import)
+- [`replace-use-form-state`](https://github.com/reactjs/react-codemod?tab=readme-ov-file#replace-use-form-state)
+- [`prop-types-typescript`](https://github.com/reactjs/react-codemod#react-proptypes-to-prop-types)
+
+This does not include the TypeScript changes. See [TypeScript changes](#typescript-changes) below.
+
+
+
+Changes that include a codemod include the command below.
+
+For a list of all available codemods, see the [`react-codemod` repo](https://github.com/reactjs/react-codemod).
## Breaking changes {/*breaking-changes*/}
@@ -128,7 +153,7 @@ For more info, see the docs for [`createRoot`](https://react.dev/reference/react
### Removed deprecated React APIs {/*removed-deprecated-react-apis*/}
#### Removed: `propTypes` and `defaultProps` for functions {/*removed-proptypes-and-defaultprops*/}
-`PropTypes` were deprecated in [April 2017 (v15.5.0)](https://legacy.reactjs.org/blog/2017/04/07/react-v15.5.0.html#new-deprecation-warnings).
+`PropTypes` were deprecated in [April 2017 (v15.5.0)](https://legacy.reactjs.org/blog/2017/04/07/react-v15.5.0.html#new-deprecation-warnings).
In React 19, we're removing the `propType` checks from the React package, and using them will be silently ignored. If you're using `propTypes`, we recommend migrating to TypeScript or another type-checking solution.
@@ -158,6 +183,16 @@ function Heading({text = 'Hello, world!'}: Props) {
}
```
+
+
+Codemod `propTypes` to TypeScript with:
+
+```bash
+npx codemod@latest react/prop-types-typescript
+```
+
+
+
#### Removed: Legacy Context using `contextTypes` and `getChildContext` {/*removed-removing-legacy-context*/}
Legacy Context was deprecated in [October 2018 (v16.6.0)](https://legacy.reactjs.org/blog/2018/10/23/react-v-16-6.html).
@@ -253,7 +288,11 @@ class MyComponent extends React.Component {
-To help with the migration, we will be publishing a [react-codemod](https://github.com/reactjs/react-codemod/#string-refs) to automatically replace string refs with `ref` callbacks. Follow [this PR](https://github.com/reactjs/react-codemod/pull/309) for updates and to try it out.
+Codemod string refs with `ref` callbacks:
+
+```bash
+npx codemod@latest react/19/replace-string-ref
+```
@@ -309,7 +348,7 @@ npm install react-shallow-renderer --save-dev
##### Please reconsider shallow rendering {/*please-reconsider-shallow-rendering*/}
-Shallow rendering depends on React internals and can block you from future upgrades. We recommend migrating your tests to [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@testing-library/react-native](https://callstack.github.io/react-native-testing-library/docs/getting-started).
+Shallow rendering depends on React internals and can block you from future upgrades. We recommend migrating your tests to [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@testing-library/react-native](https://testing-library.com/docs/react-native-testing-library/intro).
@@ -340,6 +379,16 @@ All other `test-utils` functions have been removed. These utilities were uncommo
See the [warning page](https://react.dev/warnings/react-dom-test-utils) for alternatives.
+
+
+Codemod `ReactDOMTestUtils.act` to `React.act`:
+
+```bash
+npx codemod@latest react/19/replace-act-import
+```
+
+
+
#### Removed: `ReactDOM.render` {/*removed-reactdom-render*/}
`ReactDOM.render` was deprecated in [March 2022 (v18.0.0)](https://react.dev/blog/2022/03/08/react-18-upgrade-guide). In React 19, we're removing `ReactDOM.render` and you'll need to migrate to using [`ReactDOM.createRoot`](https://react.dev/reference/react-dom/client/createRoot):
@@ -355,6 +404,16 @@ const root = createRoot(document.getElementById('root'));
root.render(
+
+Codemod `ReactDOM.render` to `ReactDOMClient.createRoot`:
+
+```bash
+npx codemod@latest react/19/replace-reactdom-render
+```
+
+
+
#### Removed: `ReactDOM.hydrate` {/*removed-reactdom-hydrate*/}
`ReactDOM.hydrate` was deprecated in [March 2022 (v18.0.0)](https://react.dev/blog/2022/03/08/react-18-upgrade-guide). In React 19, we're removing `ReactDOM.hydrate` you'll need to migrate to using [`ReactDOM.hydrateRoot`](https://react.dev/reference/react-dom/client/hydrateRoot),
@@ -369,6 +428,15 @@ import {hydrateRoot} from 'react-dom/client';
hydrateRoot(document.getElementById('root'),
+
+Codemod `ReactDOM.hydrate` to `ReactDOMClient.hydrateRoot`:
+
+```bash
+npx codemod@latest react/19/replace-reactdom-render
+```
+
+
#### Removed: `unmountComponentAtNode` {/*removed-unmountcomponentatnode*/}
@@ -385,8 +453,18 @@ root.unmount();
For more see `root.unmount()` for [`createRoot`](https://react.dev/reference/react-dom/client/createRoot#root-unmount) and [`hydrateRoot`](https://react.dev/reference/react-dom/client/hydrateRoot#root-unmount).
+
+
+Codemod `unmountComponentAtNode` to `root.unmount`:
+
+```bash
+npx codemod@latest react/19/replace-reactdom-render
+```
+
+
#### Removed: `ReactDOM.findDOMNode` {/*removed-reactdom-finddomnode*/}
+
`ReactDOM.findDOMNode` was [deprecated in October 2018 (v16.6.0)](https://legacy.reactjs.org/blog/2018/10/23/react-v-16-6.html#deprecations-in-strictmode).
We're removing `findDOMNode` because it was a legacy escape hatch that was slow to execute, fragile to refactoring, only returned the first child, and broke abstraction levels (see more [here](https://legacy.reactjs.org/docs/strict-mode.html#warning-about-deprecated-finddomnode-usage)). You can replace `ReactDOM.findDOMNode` with [DOM refs](/learn/manipulating-the-dom-with-refs):
@@ -441,7 +519,7 @@ We are deprecating `react-test-renderer` because it implements its own renderer
The test renderer was created before there were more viable testing strategies available like [React Testing Library](https://testing-library.com), and we now recommend using a modern testing library instead.
-In React 19, `react-test-renderer` logs a deprecation warning, and has switched to concurrent rendering. We recommend migrating your tests to [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@testing-library/react-native](https://callstack.github.io/react-native-testing-library/docs/getting-started) for a modern and well supported testing experience.
+In React 19, `react-test-renderer` logs a deprecation warning, and has switched to concurrent rendering. We recommend migrating your tests to [@testing-library/react](https://testing-library.com/docs/react-testing-library/intro/) or [@testing-library/react-native](https://testing-library.com/docs/react-native-testing-library/intro) for a modern and well supported testing experience.
## Notable changes {/*notable-changes*/}
@@ -453,6 +531,24 @@ When double rendering in Strict Mode in development, `useMemo` and `useCallback`
As with all Strict Mode behaviors, these features are designed to proactively surface bugs in your components during development so you can fix them before they are shipped to production. For example, during development, Strict Mode will double-invoke ref callback functions on initial mount, to simulate what happens when a mounted component is replaced by a Suspense fallback.
+### Improvements to Suspense {/*improvements-to-suspense*/}
+
+In React 19, when a component suspends, React will immediately commit the fallback of the nearest Suspense boundary without waiting for the entire sibling tree to render. After the fallback commits, React schedules another render for the suspended siblings to "pre-warm" lazy requests in the rest of the tree:
+
+
+
+Previously, when a component suspended, the suspended siblings were rendered and then the fallback was committed.
+
+
+
+
+
+In React 19, when a component suspends, the fallback is committed and then the suspended siblings are rendered.
+
+
+
+This change means Suspense fallbacks display faster, while still warming lazy requests in the suspended tree.
+
### UMD builds removed {/*umd-builds-removed*/}
UMD was widely used in the past as a convenient way to load React without a build step. Now, there are modern alternatives for loading modules as scripts in HTML documents. Starting with React 19, React will no longer produce UMD builds to reduce the complexity of its testing and release process.
@@ -634,12 +730,12 @@ const reducer = (state: State, action: Action) => state;
### 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**: Error for javascript URLs in `src` and `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-dom**: Remove `unstable_runWithPriority` [#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*/}
@@ -651,7 +747,7 @@ const reducer = (state: State, action: Action) => state;
- **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.
+For a full list of changes, please see the [Changelog](https://github.com/facebook/react/blob/main/CHANGELOG.md#1900-december-5-2024).
---
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..7cb7d42ee
--- /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).
+
+---
+
+
+
+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.
+
+
+
+---
+
+At React Conf 2024, we announced the [React 19 RC](/blog/2024/12/05/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/2024/12/05/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://bsky.app/profile/danabra.mov)
+- [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:
+
+
+
+### React Compiler is now in RC! {/*react-compiler-is-now-in-rc*/}
+
+Please see the [RC blog post](/blog/2025/04/21/react-compiler-rc) for details.
+
+
+
+
+
+The React team is excited to share new updates:
+
+
+
+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:
+
+
+npm install -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta
+
+
+Or, if you're using Yarn:
+
+
+yarn add -D babel-plugin-react-compiler@beta eslint-plugin-react-compiler@beta
+
+
+You can watch [Sathya Gunasekaran's](https://twitter.com/_gsathya) talk at React India here:
+
+
+npm install -D eslint-plugin-react-compiler@beta
+
+
+Or, if you're using Yarn:
+
+
+yarn add -D eslint-plugin-react-compiler@beta
+
+
+After installation you can enable the linter by [adding it to your ESLint config](/learn/react-compiler/installation#eslint-integration). 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](/reference/react-compiler/configuration#react-17-18).
+
+## 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.](/reference/react-compiler/compiling-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/2024/04/25/react-19.md b/src/content/blog/2024/12/05/react-19.md
similarity index 92%
rename from src/content/blog/2024/04/25/react-19.md
rename to src/content/blog/2024/12/05/react-19.md
index 1ccffa1c8..65bf42757 100644
--- a/src/content/blog/2024/04/25/react-19.md
+++ b/src/content/blog/2024/12/05/react-19.md
@@ -1,27 +1,33 @@
---
-title: "React 19 Beta"
+title: "React v19"
author: The React Team
-date: 2024/04/25
-description: React 19 Beta 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.
+date: 2024/12/05
+description: React 19 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)
+December 05, 2024 by [The React Team](/community/team)
---
-
-This beta release is for libraries to prepare for React 19. App developers should upgrade to 18.3.0 and wait for React 19 stable as we work with libraries and make changes based on feedback.
+### React 19 is now stable! {/*react-19-is-now-stable*/}
+
+Additions since this post was originally shared with the React 19 RC in April:
+
+- **Pre-warming for suspended trees**: see [Improvements to Suspense](/blog/2024/04/25/react-19-upgrade-guide#improvements-to-suspense).
+- **React DOM static APIs**: see [New React DOM Static APIs](#new-react-dom-static-apis).
+
+_The date for this post has been updated to reflect the stable release date._
-React 19 Beta is now available on npm!
+React v19 is now available on npm!
-In our [React 19 Beta Upgrade Guide](/blog/2024/04/25/react-19-upgrade-guide), we shared step-by-step instructions for upgrading your app to React 19 Beta. In this post, we'll give an overview of the new features in React 19, and how you can adopt them.
+In our [React 19 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)
@@ -288,7 +294,7 @@ A component was suspended by an uncached promise. Creating promises inside a Cli
-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.
+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.
@@ -318,6 +324,30 @@ The `use` API can only be called in render, similar to hooks. Unlike hooks, `use
For more information, see the docs for [`use`](/reference/react/use).
+## New React DOM Static APIs {/*new-react-dom-static-apis*/}
+
+We've added two new APIs to `react-dom/static` for static site generation:
+- [`prerender`](/reference/react-dom/static/prerender)
+- [`prerenderToNodeStream`](/reference/react-dom/static/prerenderToNodeStream)
+
+These new APIs improve on `renderToString` by waiting for data to load for static HTML generation. They are designed to work with streaming environments like Node.js Streams and Web Streams. For example, in a Web Stream environment, you can prerender a React tree to static HTML with `prerender`:
+
+```js
+import { prerender } from 'react-dom/static';
+
+async function handler(request) {
+ const {prelude} = await prerender(
-`refs` passed to classes are not passed as props since they reference the component instance.
+`ref`s passed to classes are not passed as props since they reference the component instance.
@@ -510,8 +540,7 @@ Due to the introduction of ref cleanup functions, returning anything else from a
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).
+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*/}
@@ -778,5 +807,4 @@ Thanks to [Joey Arhar](https://github.com/josepharhar) for driving the design an
#### 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.
-
-
+_Note: this post was originally published 04/25/2024 and has been updated to 12/05/2024 with the stable release._
diff --git a/src/content/blog/2025/02/14/sunsetting-create-react-app.md b/src/content/blog/2025/02/14/sunsetting-create-react-app.md
new file mode 100644
index 000000000..9ced6231c
--- /dev/null
+++ b/src/content/blog/2025/02/14/sunsetting-create-react-app.md
@@ -0,0 +1,320 @@
+---
+title: "Sunsetting Create React App"
+author: Matt Carroll and Ricky Hanlon
+date: 2025/02/14
+description: Today, we’re deprecating Create React App for new apps, and encouraging existing apps to migrate to a framework, or to migrate to a build tool like Vite, Parcel, or RSBuild. We’re also providing docs for when a framework isn’t a good fit for your project, you want to build your own framework, or you just want to learn how React works by building a React app from scratch.
+---
+
+February 14, 2025 by [Matt Carroll](https://twitter.com/mattcarrollcode) and [Ricky Hanlon](https://bsky.app/profile/ricky.fm)
+
+---
+
+
+
+Today, we’re deprecating [Create React App](https://create-react-app.dev/) for new apps, and encouraging existing apps to migrate to a [framework](#how-to-migrate-to-a-framework), or to [migrate to a build tool](#how-to-migrate-to-a-build-tool) like Vite, Parcel, or RSBuild.
+
+We’re also providing docs for when a framework isn’t a good fit for your project, you want to build your own framework, or you just want to learn how React works by [building a React app from scratch](/learn/build-a-react-app-from-scratch).
+
+
+
+-----
+
+When we released Create React App in 2016, there was no clear way to build a new React app.
+
+To create a React app, you had to install a bunch of tools and wire them up together yourself to support basic features like JSX, linting, and hot reloading. This was very tricky to do correctly, so the [community](https://github.com/react-boilerplate/react-boilerplate) [created](https://github.com/kriasoft/react-starter-kit) [boilerplates](https://github.com/petehunt/react-boilerplate) for [common](https://github.com/gaearon/react-hot-boilerplate) [setups](https://github.com/erikras/react-redux-universal-hot-example). However, boilerplates were difficult to update and fragmentation made it difficult for React to release new features.
+
+Create React App solved these problems by combining several tools into a single recommended configuration. This allowed apps a simple way to upgrade to new tooling features, and allowed the React team to deploy non-trivial tooling changes (Fast Refresh support, React Hooks lint rules) to the broadest possible audience.
+
+This model became so popular that there's an entire category of tools working this way today.
+
+## Deprecating Create React App {/*deprecating-create-react-app*/}
+
+Although Create React App makes it easy to get started, [there are several limitations](#limitations-of-build-tools) that make it difficult to build high performant production apps. In principle, we could solve these problems by essentially evolving it into a [framework](#why-we-recommend-frameworks).
+
+However, since Create React App currently has no active maintainers, and there are many existing frameworks that solve these problems already, we’ve decided to deprecate Create React App.
+
+Starting today, if you install a new app, you will see a deprecation warning:
+
+
+
+
+create-react-app is deprecated.
+{'\n\n'}
+You can find a list of up-to-date React frameworks on react.dev
+For more info see: react.dev/link/cra
+{'\n\n'}
+This error message will only be shown once per install.
+
+
+
+
+We've also added a deprecation notice to the Create React App [website](https://create-react-app.dev/) and GitHub [repo](https://github.com/facebook/create-react-app). Create React App will continue working in maintenance mode, and we've published a new version of Create React App to work with React 19.
+
+## How to Migrate to a Framework {/*how-to-migrate-to-a-framework*/}
+We recommend [creating new React apps](/learn/creating-a-react-app) with a framework. All the frameworks we recommend support client-side rendering ([CSR](https://developer.mozilla.org/en-US/docs/Glossary/CSR)) and single-page apps ([SPA](https://developer.mozilla.org/en-US/docs/Glossary/SPA)), and can be deployed to a CDN or static hosting service without a server.
+
+For existing apps, these guides will help you migrate to a client-only SPA:
+
+* [Next.js’ Create React App migration guide](https://nextjs.org/docs/app/building-your-application/upgrading/from-create-react-app)
+* [React Router’s framework adoption guide](https://reactrouter.com/upgrading/component-routes).
+* [Expo webpack to Expo Router migration guide](https://docs.expo.dev/router/migrate/from-expo-webpack/)
+
+## How to Migrate to a Build Tool {/*how-to-migrate-to-a-build-tool*/}
+
+If your app has unusual constraints, or you prefer to solve these problems by building your own framework, or you just want to learn how react works from scratch, you can roll your own custom setup with React using Vite, Parcel or Rsbuild.
+
+For existing apps, these guides will help you migrate to a build tool:
+
+* [Vite Create React App migration guide](https://www.robinwieruch.de/vite-create-react-app/)
+* [Parcel Create React App migration guide](https://parceljs.org/migration/cra/)
+* [Rsbuild Create React App migration guide](https://rsbuild.dev/guide/migration/cra)
+
+To help get started with Vite, Parcel or Rsbuild, we've added new docs for [Building a React App from Scratch](/learn/build-a-react-app-from-scratch).
+
+
+
+#### Do I need a framework? {/*do-i-need-a-framework*/}
+
+Most apps would benefit from a framework, but there are valid cases to build a React app from scratch. A good rule of thumb is if your app needs routing, you would probably benefit from a framework.
+
+Just like Svelte has Sveltekit, Vue has Nuxt, and Solid has SolidStart, [React recommends using a framework](#why-we-recommend-frameworks) that fully integrates routing into features like data-fetching and code-splitting out of the box. This avoids the pain of needing to write your own complex configurations and essentially build a framework yourself.
+
+However, you can always [build a React app from scratch](/learn/build-a-react-app-from-scratch) using a build tool like Vite, Parcel, or Rsbuild.
+
+
+
+Continue reading to learn more about the [limitations of build tools](#limitations-of-build-tools) and [why we recommend frameworks](#why-we-recommend-frameworks).
+
+## Limitations of Build Tools {/*limitations-of-build-tools*/}
+
+Create React App and build tools like it make it easy to get started building a React app. After running `npx create-react-app my-app`, you get a fully configured React app with a development server, linting, and a production build.
+
+For example, if you're building an internal admin tool, you can start with a landing page:
+
+```js
+export default function App() {
+ return (
+
+
Welcome to the Admin Tool!
+
+ )
+}
+```
+
+This allows you to immediately start coding in React with features like JSX, default linting rules, and a bundler to run in both development and production. However, this setup is missing the tools you need to build a real production app.
+
+Most production apps need solutions to problems like routing, data fetching, and code splitting.
+
+### Routing {/*routing*/}
+
+Create React App does not include a specific routing solution. If you're just getting started, one option is to use `useState` to switch between routes. But doing this means that you can't share links to your app - every link would go to the same page - and structuring your app becomes difficult over time:
+
+```js
+import {useState} from 'react';
+
+import Home from './Home';
+import Dashboard from './Dashboard';
+
+export default function App() {
+ // ❌ Routing in state does not create URLs
+ const [route, setRoute] = useState('home');
+ return (
+
+ {route === 'home' &&
+ )
+}
+```
+
+This is why most apps that use Create React App solve add routing with a routing library like [React Router](https://reactrouter.com/) or [Tanstack Router](https://tanstack.com/router/latest). With a routing library, you can add additional routes to the app, which provides opinions on the structure of your app, and allows you to start sharing links to routes. For example, with React Router you can define routes:
+
+```js
+import {RouterProvider, createBrowserRouter} from 'react-router';
+
+import Home from './Home';
+import Dashboard from './Dashboard';
+
+// ✅ Each route has it's own URL
+const router = createBrowserRouter([
+ {path: '/', element:
+ {data.map(item =>
{item.name}
)}
+
+ {loaderData.map(item =>
{item.name}
)}
+
+
+ Accessibility
+ Asset loading
+ Authentication
+ Caching
+
+
+ Error handling
+ Mutating data
+ Navigations
+ Optimistic updates
+
+
+ Progressive enhancement
+ Server-side rendering
+ Static site generation
+ Streaming
+
+
+
+#### Server rendering is optional {/*server-rendering-is-optional*/}
+
+The frameworks we recommend all provide the option to create a [client-side rendered (CSR)](https://developer.mozilla.org/en-US/docs/Glossary/CSR) app.
+
+In some cases, CSR is the right choice for a page, but many times it's not. Even if most of your app is client-side, there are often individual pages that could benefit from server rendering features like [static-site generation (SSG)](https://developer.mozilla.org/en-US/docs/Glossary/SSG) or [server-side rendering (SSR)](https://developer.mozilla.org/en-US/docs/Glossary/SSR), for example a Terms of Service page, or documentation.
+
+Server rendering generally sends less JavaScript to the client, and a full HTML document which produces a faster [First Contentful Paint (FCP)](https://web.dev/articles/fcp) by reducing [Total Blocking Time (TBD)](https://web.dev/articles/tbt), which can also lower [Interaction to Next Paint (INP)](https://web.dev/articles/inp). This is why the [Chrome team has encouraged](https://web.dev/articles/rendering-on-the-web) developers to consider static or server-side render over a full client-side approach to achieve the best possible performance.
+
+There are tradeoffs to using a server, and it is not always the best option for every page. Generating pages on the server incurs additional cost and takes time to generate which can increase [Time to First Byte (TTFB)](https://web.dev/articles/ttfb). The best performing apps are able to pick the right rendering strategy on a per-page basis, based on the tradeoffs of each strategy.
+
+Frameworks provide the option to use a server on any page if you want to, but do not force you to use a server. This allows you to pick the right rendering strategy for each page in your app.
+
+#### What About Server Components {/*server-components*/}
+
+The frameworks we recommend also include support for React Server Components.
+
+Server Components help solve these problems by moving routing and data fetching to the server, and allowing code splitting to be done for client components based on the data you render, instead of just the route rendered, and reducing the amount of JavaScript shipped for the best possible [loading sequence](https://www.patterns.dev/vanilla/loading-sequence).
+
+Server Components do not require a server. They can be run at build time on your CI server to create a static-site generated app (SSG) app, at runtime on a web server for a server-side rendered (SSR) app.
+
+See [Introducing zero-bundle size React Server Components](/blog/2020/12/21/data-fetching-with-react-server-components) and [the docs](/reference/rsc/server-components) for more info.
+
+
+
+
+
+#### Server Rendering is not just for SEO {/*server-rendering-is-not-just-for-seo*/}
+
+A common misunderstanding is that server rendering is only for [SEO](https://developer.mozilla.org/en-US/docs/Glossary/SEO).
+
+While server rendering can improve SEO, it also improves performance by reducing the amount of JavaScript the user needs to download and parse before they can see the content on the screen.
+
+This is why the Chrome team [has encouraged](https://web.dev/articles/rendering-on-the-web) developers to consider static or server-side render over a full client-side approach to achieve the best possible performance.
+
+
+
+---
+
+_Thank you to [Dan Abramov](https://bsky.app/profile/danabra.mov) for creating Create React App, and [Joe Haddad](https://github.com/Timer), [Ian Schmitz](https://github.com/ianschmitz), [Brody McKee](https://github.com/mrmckeb), and [many others](https://github.com/facebook/create-react-app/graphs/contributors) for maintaining Create React App over the years. Thank you to [Brooks Lybrand](https://bsky.app/profile/brookslybrand.bsky.social), [Dan Abramov](https://bsky.app/profile/danabra.mov), [Devon Govett](https://bsky.app/profile/devongovett.bsky.social), [Eli White](https://x.com/Eli_White), [Jack Herrington](https://bsky.app/profile/jherr.dev), [Joe Savona](https://x.com/en_JS), [Lauren Tan](https://bsky.app/profile/no.lol), [Lee Robinson](https://x.com/leeerob), [Mark Erikson](https://bsky.app/profile/acemarke.dev), [Ryan Florence](https://x.com/ryanflorence), [Sophie Alpert](https://bsky.app/profile/sophiebits.com), [Tanner Linsley](https://bsky.app/profile/tannerlinsley.com), and [Theo Browne](https://x.com/theo) for reviewing and providing feedback on this post._
+
diff --git a/src/content/blog/2025/04/21/react-compiler-rc.md b/src/content/blog/2025/04/21/react-compiler-rc.md
new file mode 100644
index 000000000..2ebbf3bae
--- /dev/null
+++ b/src/content/blog/2025/04/21/react-compiler-rc.md
@@ -0,0 +1,128 @@
+---
+title: "React Compiler RC"
+author: Lauren Tan and Mofei Zhang
+date: 2025/04/21
+description: We are releasing the compiler's first Release Candidate (RC) today.
+
+---
+
+April 21, 2025 by [Lauren Tan](https://x.com/potetotes) and [Mofei Zhang](https://x.com/zmofei).
+
+---
+
+
+
+The React team is excited to share new updates:
+
+
+
+1. We're publishing React Compiler RC today, in preparation of the compiler's stable release.
+2. We're merging `eslint-plugin-react-compiler` into `eslint-plugin-react-hooks`.
+3. We've added support for swc and are working with oxc to support Babel-free builds.
+
+---
+
+[React Compiler](https://react.dev/learn/react-compiler) is a build-time tool that optimizes your React app through automatic memoization. Last year, we published React Compiler’s [first beta](https://react.dev/blog/2024/10/21/react-compiler-beta-release) and received lots of great feedback and contributions. We’re excited about the wins we’ve seen from folks adopting the compiler (see case studies from [Sanity Studio](https://github.com/reactwg/react-compiler/discussions/33) and [Wakelet](https://github.com/reactwg/react-compiler/discussions/52)) and are working towards a stable release.
+
+We are releasing the compiler's first Release Candidate (RC) today. The RC is intended to be a stable and near-final version of the compiler, and safe to try out in production.
+
+## Use React Compiler RC today {/*use-react-compiler-rc-today*/}
+To install the RC:
+
+npm
+
+{`npm install --save-dev --save-exact babel-plugin-react-compiler@rc`}
+
+
+pnpm
+
+{`pnpm add --save-dev --save-exact babel-plugin-react-compiler@rc`}
+
+
+yarn
+
+{`yarn add --dev --exact babel-plugin-react-compiler@rc`}
+
+
+As part of the RC, we've been making React Compiler easier to add to your projects and added optimizations to how the compiler generates memoization. React Complier now supports optional chains and array indices as dependencies. We're exploring how to infer even more dependencies like equality checks and string interpolation. These improvements ultimately result in fewer re-renders and more responsive UIs.
+
+We have also heard from the community that the ref-in-render validation sometimes has false positives. Since as a general philosophy we want you to be able to fully trust in the compiler's error messages and hints, we are turning it off by default for now. We will keep working to improve this validation, and we will re-enable it in a follow up release.
+
+You can find more details on using the Compiler in [our docs](https://react.dev/learn/react-compiler).
+
+## Feedback {/*feedback*/}
+During the RC period, we encourage all React users to try the compiler and provide feedback in the React repo. Please [open an issue](https://github.com/facebook/react/issues) if you encounter any bugs or unexpected behavior. If you have a general question or suggestion, please post them in the [React Compiler Working Group](https://github.com/reactwg/react-compiler/discussions).
+
+## Backwards Compatibility {/*backwards-compatibility*/}
+As noted in the Beta announcement, React Compiler is compatible with React 17 and up. If you are not yet on React 19, you can use 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](https://react.dev/learn/react-compiler#using-react-compiler-with-react-17-or-18).
+
+## Migrating from eslint-plugin-react-compiler to eslint-plugin-react-hooks {/*migrating-from-eslint-plugin-react-compiler-to-eslint-plugin-react-hooks*/}
+If you have already installed eslint-plugin-react-compiler, you can now remove it and use `eslint-plugin-react-hooks@rc`. Many thanks to [@michaelfaith](https://bsky.app/profile/michael.faith) for contributing to this improvement!
+
+To install:
+
+npm
+
+{`npm install --save-dev eslint-plugin-react-hooks@rc`}
+
+
+pnpm
+
+{`pnpm add --save-dev eslint-plugin-react-hooks@rc`}
+
+
+yarn
+
+{`yarn add --dev eslint-plugin-react-hooks@rc`}
+
+
+```js
+// eslint.config.js
+import * as reactHooks from 'eslint-plugin-react-hooks';
+
+export default [
+ // Flat Config (eslint 9+)
+ reactHooks.configs.recommended,
+
+ // Legacy Config
+ reactHooks.configs['recommended-latest']
+];
+```
+
+To enable the React Compiler rule, add `'react-hooks/react-compiler': 'error'` to your ESLint configuration.
+
+The linter does not require the compiler to be installed, so there's no risk in upgrading eslint-plugin-react-hooks. We recommend everyone upgrade today.
+
+## swc support (experimental) {/*swc-support-experimental*/}
+React Compiler can be installed across [several build tools](/learn/react-compiler#installation) such as Babel, Vite, and Rsbuild.
+
+In addition to those tools, we have been collaborating with Kang Dongyoon ([@kdy1dev](https://x.com/kdy1dev)) from the [swc](https://swc.rs/) team on adding additional support for React Compiler as an swc plugin. While this work isn't done, Next.js build performance should now be considerably faster when the [React Compiler is enabled in your Next.js app](https://nextjs.org/docs/app/api-reference/config/next-config-js/reactCompiler).
+
+We recommend using Next.js [15.3.1](https://github.com/vercel/next.js/releases/tag/v15.3.1) or greater to get the best build performance.
+
+Vite users can continue to use [vite-plugin-react](https://github.com/vitejs/vite-plugin-react) to enable the compiler, by adding it as a [Babel plugin](https://react.dev/learn/react-compiler#usage-with-vite). We are also working with the [oxc](https://oxc.rs/) team to [add support for the compiler](https://github.com/oxc-project/oxc/issues/10048). Once [rolldown](https://github.com/rolldown/rolldown) is officially released and supported in Vite and oxc support is added for React Compiler, we'll update the docs with information on how to migrate.
+
+## Upgrading React Compiler {/*upgrading-react-compiler*/}
+React Compiler works best when the auto-memoization applied is strictly for performance. Future versions of the compiler may change how memoization is applied, for example it could become more granular and precise.
+
+However, because product code may sometimes break the [rules of React](https://react.dev/reference/rules) in ways that aren't always statically detectable in JavaScript, changing memoization can occasionally have unexpected results. For example, a previously memoized value might be used as a dependency for a useEffect somewhere in the component tree. Changing how or whether this value is memoized can cause over or under-firing of that useEffect. While we encourage [useEffect only for synchronization](https://react.dev/learn/synchronizing-with-effects), your codebase may have useEffects that cover other use-cases such as effects that needs to only run in response to specific values changing.
+
+In other words, changing memoization may under rare circumstances cause unexpected behavior. For this reason, we recommend following the Rules of React and employing continuous end-to-end testing of your app so you can upgrade the compiler with confidence and identify any rules of React violations that might cause issues.
+
+If you don't have good test coverage, we recommend pinning the compiler to an exact version (eg `19.1.0`) rather than a SemVer range (eg `^19.1.0`). You can do this by passing the `--save-exact` (npm/pnpm) or `--exact` flags (yarn) when upgrading the compiler. You should then do any upgrades of the compiler manually, taking care to check that your app still works as expected.
+
+## Roadmap to Stable {/*roadmap-to-stable*/}
+*This is not a final roadmap, and is subject to change.*
+
+After a period of final feedback from the community on the RC, we plan on a Stable Release for the compiler.
+
+* ✅ Experimental: Released at React Conf 2024, primarily for feedback from application developers.
+* ✅ Public Beta: Available today, for feedback from library authors.
+* ✅ 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.
+
+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. Each upgrade will continue to improve performance and add better handling of diverse JavaScript and React patterns.
+
+---
+
+Thanks to [Joe Savona](https://x.com/en_JS), [Jason Bonta](https://x.com/someextent), [Jimmy Lai](https://x.com/feedthejim), and [Kang Dongyoon](https://x.com/kdy1dev) (@kdy1dev) for reviewing and editing this post.
diff --git a/src/content/blog/2025/04/23/react-labs-view-transitions-activity-and-more.md b/src/content/blog/2025/04/23/react-labs-view-transitions-activity-and-more.md
new file mode 100644
index 000000000..c7f740091
--- /dev/null
+++ b/src/content/blog/2025/04/23/react-labs-view-transitions-activity-and-more.md
@@ -0,0 +1,14366 @@
+---
+title: "React Labs: View Transitions, Activity, and more"
+author: Ricky Hanlon
+date: 2025/04/23
+description: In React Labs posts, we write about projects in active research and development. In this post, we're sharing two new experimental features that are ready to try today, and updates on other areas we're working on now.
+---
+
+April 23, 2025 by [Ricky Hanlon](https://twitter.com/rickhanlonii)
+
+---
+
+
+
+In React Labs posts, we write about projects in active research and development. In this post, we're sharing two new experimental features that are ready to try today, and updates on other areas we're working on now.
+
+
+
+
+
+
+React Conf 2025 is scheduled for October 7–8 in Henderson, Nevada!
+
+We're looking for speakers to help us create talks about the features covered in this post. If you're interested in speaking at ReactConf, [please apply here](https://forms.reform.app/react-conf/call-for-speakers/) (no talk proposal required).
+
+For more info on tickets, free streaming, sponsoring, and more, see [the React Conf website](https://conf.react.dev).
+
+
+
+Today, we're excited to release documentation for two new experimental features that are ready for testing:
+
+- [View Transitions](#view-transitions)
+- [Activity](#activity)
+
+We're also sharing updates on new features currently in development:
+- [React Performance Tracks](#react-performance-tracks)
+- [Compiler IDE Extension](#compiler-ide-extension)
+- [Automatic Effect Dependencies](#automatic-effect-dependencies)
+- [Fragment Refs](#fragment-refs)
+- [Concurrent Stores](#concurrent-stores)
+
+---
+
+# New Experimental Features {/*new-experimental-features*/}
+
+View Transitions and Activity are now ready for testing in `react@experimental`. These features have been tested in production and are stable, but the final API may still change as we incorporate feedback.
+
+You can try them by upgrading React packages to the most recent experimental version:
+
+- `react@experimental`
+- `react-dom@experimental`
+
+Read on to learn how to use these features in your app, or check out the newly published docs:
+
+- [``](/reference/react/ViewTransition): A component that lets you activate an animation for a Transition.
+- [`addTransitionType`](/reference/react/addTransitionType): A function that allows you to specify the cause of a Transition.
+- [``](/reference/react/Activity): A component that lets you hide and show parts of the UI.
+
+## View Transitions {/*view-transitions*/}
+
+React View Transitions are a new experimental feature that makes it easier to add animations to UI transitions in your app. Under-the-hood, these animations use the new [`startViewTransition`](https://developer.mozilla.org/en-US/docs/Web/API/Document/startViewTransition) API available in most modern browsers.
+
+To opt-in to animating an element, wrap it in the new `` component:
+
+```js
+// "what" to animate.
+
+ animate me
+
+```
+
+This new component lets you declaratively define "what" to animate when an animation is activated.
+
+You can define "when" to animate by using one of these three triggers for a View Transition:
+
+```js
+// "when" to animate.
+
+// Transitions
+startTransition(() => setState(...));
+
+// Deferred Values
+const deferred = useDeferredValue(value);
+
+// Suspense
+Loading...
+
+```
+
+By default, these animations use the [default CSS animations for View Transitions](https://developer.mozilla.org/en-US/docs/Web/API/View_Transition_API/Using#customizing_your_animations) applied (typically a smooth cross-fade). You can use [view transition pseudo-selectors](https://developer.mozilla.org/en-US/docs/Web/API/View_Transition_API/Using#the_view_transition_pseudo-element_tree) to define "how" the animation runs. For example, you can use `*` to change the default animation for all transitions:
+
+```
+// "how" to animate.
+::view-transition-old(*) {
+ animation: 300ms ease-out fade-out;
+}
+::view-transition-new(*) {
+ animation: 300ms ease-in fade-in;
+}
+```
+
+When the DOM updates due to an animation trigger—like `startTransition`, `useDeferredValue`, or a `Suspense` fallback switching to content—React will use [declarative heuristics](/reference/react/ViewTransition#viewtransition) to automatically determine which `` components to activate for the animation. The browser will then run the animation that's defined in CSS.
+
+If you're familiar with the browser's View Transition API and want to know how React supports it, check out [How does `` Work](/reference/react/ViewTransition#how-does-viewtransition-work) in the docs.
+
+In this post, let's take a look at a few examples of how to use View Transitions.
+
+We'll start with this app, which doesn't animate any of the following interactions:
+- Click a video to view the details.
+- Click "back" to go back to the feed.
+- Type in the list to filter the videos.
+
+
+
+```js src/App.js active
+import TalkDetails from './Details'; import Home from './Home'; import {useRouter} from './router';
+
+export default function App() {
+ const {url} = useRouter();
+
+ // 🚩This version doesn't include any animations yet
+ return url === '/' ? {details.title}
+ {details.description}
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+ }
+ >
+
+
+
+
+
+ );
+}
+
+```
+
+```js src/Home.js
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+
{count} Videos }>
+
+
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+ );
+}
+
+```
+
+```js src/Icons.js
+export function ChevronLeft() {
+ return (
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js
+import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+ return (
+
+
+
+ {heading}
+ {isPending &&
+
+
+
+
+ );
+}
+```
+
+```js src/LikeButton.js
+import {useState} from 'react';
+import {Heart} from './Icons';
+
+// A hack since we don't actually have a backend.
+// Unlike local state, this survives videos being filtered.
+const likedVideos = new Set();
+
+export default function LikeButton({video}) {
+ const [isLiked, setIsLiked] = useState(() => likedVideos.has(video.id));
+ const [animate, setAnimate] = useState(false);
+ return (
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js
+import { useState } from "react";
+import LikeButton from "./LikeButton";
+import { useRouter } from "./router";
+import { PauseIcon, PlayIcon } from "./Icons";
+import { startTransition } from "react";
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Thumbnail({ video, children }) {
+ return (
+
+ {children}
+
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ );
+}
+```
+
+
+```js src/data.js hidden
+const videos = [
+ {
+ id: '1',
+ title: 'First video',
+ description: 'Video description',
+ image: 'blue',
+ },
+ {
+ id: '2',
+ title: 'Second video',
+ description: 'Video description',
+ image: 'red',
+ },
+ {
+ id: '3',
+ title: 'Third video',
+ description: 'Video description',
+ image: 'green',
+ },
+ {
+ id: '4',
+ title: 'Fourth video',
+ description: 'Video description',
+ image: 'purple',
+ },
+ {
+ id: '5',
+ title: 'Fifth video',
+ description: 'Video description',
+ image: 'yellow',
+ },
+ {
+ id: '6',
+ title: 'Sixth video',
+ description: 'Video description',
+ image: 'gray',
+ },
+];
+
+let videosCache = new Map();
+let videoCache = new Map();
+let videoDetailsCache = new Map();
+const VIDEO_DELAY = 1;
+const VIDEO_DETAILS_DELAY = 1000;
+export function fetchVideos() {
+ if (videosCache.has(0)) {
+ return videosCache.get(0);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos);
+ }, VIDEO_DELAY);
+ });
+ videosCache.set(0, promise);
+ return promise;
+}
+
+export function fetchVideo(id) {
+ if (videoCache.has(id)) {
+ return videoCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DELAY);
+ });
+ videoCache.set(id, promise);
+ return promise;
+}
+
+export function fetchVideoDetails(id) {
+ if (videoDetailsCache.has(id)) {
+ return videoDetailsCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DETAILS_DELAY);
+ });
+ videoDetailsCache.set(id, promise);
+ return promise;
+}
+```
+
+```js src/router.js
+import {
+ useState,
+ createContext,
+ use,
+ useTransition,
+ useLayoutEffect,
+ useEffect,
+} from "react";
+
+const RouterContext = createContext({ url: "/", params: {} });
+
+export function useRouter() {
+ return use(RouterContext);
+}
+
+export function useIsNavPending() {
+ return use(RouterContext).isPending;
+}
+
+export function Router({ children }) {
+ const [routerState, setRouterState] = useState({
+ pendingNav: () => {},
+ url: document.location.pathname,
+ });
+ const [isPending, startTransition] = useTransition();
+
+ function go(url) {
+ setRouterState({
+ url,
+ pendingNav() {
+ window.history.pushState({}, "", url);
+ },
+ });
+ }
+ function navigate(url) {
+ // Update router state in transition.
+ startTransition(() => {
+ go(url);
+ });
+ }
+
+ function navigateBack(url) {
+ // Update router state in transition.
+ startTransition(() => {
+ go(url);
+ });
+ }
+
+ useEffect(() => {
+ function handlePopState() {
+ // This should not animate because restoration has to be synchronous.
+ // Even though it's a transition.
+ startTransition(() => {
+ setRouterState({
+ url: document.location.pathname + document.location.search,
+ pendingNav() {
+ // Noop. URL has already updated.
+ },
+ });
+ });
+ }
+ window.addEventListener("popstate", handlePopState);
+ return () => {
+ window.removeEventListener("popstate", handlePopState);
+ };
+ }, []);
+ const pendingNav = routerState.pendingNav;
+ useLayoutEffect(() => {
+ pendingNav();
+ }, [pendingNav]);
+
+ return (
+
+ {children}
+
+ );
+}
+```
+
+```css src/styles.css
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+
+
+#### View Transitions do not replace CSS and JS driven animations {/*view-transitions-do-not-replace-css-and-js-driven-animations*/}
+
+View Transitions are meant to be used for UI transitions such as navigation, expanding, opening, or re-ordering. They are not meant to replace all the animations in your app.
+
+In our example app above, notice that there are already animations when you click the "like" button and in the Suspense fallback glimmer. These are good use cases for CSS animations because they are animating a specific element.
+
+
+
+### Animating navigations {/*animating-navigations*/}
+
+Our app includes a Suspense-enabled router, with [page transitions already marked as Transitions](/reference/react/useTransition#building-a-suspense-enabled-router), which means navigations are performed with `startTransition`:
+
+```js
+function navigate(url) {
+ startTransition(() => {
+ go(url);
+ });
+}
+```
+
+`startTransition` is a View Transition trigger, so we can add `
` to animate between pages:
+
+```js
+// "what" to animate
+
+ {url === '/' ?
+```
+
+When the `url` changes, the `` and new route are rendered. Since the `` was updated inside of `startTransition`, the `` is activated for an animation.
+
+
+By default, View Transitions include the browser default cross-fade animation. Adding this to our example, we now have a cross-fade whenever we navigate between pages:
+
+
+
+```js src/App.js active
+import {unstable_ViewTransition as ViewTransition} from 'react'; import Details from './Details'; import Home from './Home'; import {useRouter} from './router';
+
+export default function App() {
+ const {url} = useRouter();
+
+ // Use ViewTransition to animate between pages.
+ // No additional CSS needed by default.
+ return (
+
+ {url === '/' ?
+ );
+}
+```
+
+```js src/Details.js hidden
+import { fetchVideo, fetchVideoDetails } from "./data";
+import { Thumbnail, VideoControls } from "./Videos";
+import { useRouter } from "./router";
+import Layout from "./Layout";
+import { use, Suspense } from "react";
+import { ChevronLeft } from "./Icons";
+
+function VideoInfo({ id }) {
+ const details = use(fetchVideoDetails(id));
+ return (
+ <>
+ {details.title}
+ {details.description}
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+ }
+ >
+
+
+
+
+
+ );
+}
+
+```
+
+```js src/Home.js hidden
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+
{count} Videos
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js
+import {unstable_ViewTransition as ViewTransition} from 'react'; import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+
+ return (
+
+
+
+ {heading}
+ {isPending &&
+
+ {/* Opt-out of ViewTransition for the content. */}
+ {/* Content can define it's own ViewTransition. */}
+
+
+
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js hidden
+import { useState } from "react";
+import LikeButton from "./LikeButton";
+import { useRouter } from "./router";
+import { PauseIcon, PlayIcon } from "./Icons";
+import { startTransition } from "react";
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Thumbnail({ video, children }) {
+ return (
+
+ {children}
+
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ {children}
+
+ );
+}
+
+const RouterContext = createContext({ url: "/", params: {} });
+
+export function useRouter() {
+ return use(RouterContext);
+}
+
+export function useIsNavPending() {
+ return use(RouterContext).isPending;
+}
+```
+
+```css src/styles.css hidden
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+Since our router already updates the route using `startTransition`, this one line change to add `` activates with the default cross-fade animation.
+
+If you're curious how this works, see the docs for [How does `` work?](/reference/react/ViewTransition#how-does-viewtransition-work)
+
+
+
+#### Opting out of `` animations {/*opting-out-of-viewtransition-animations*/}
+
+In this example, we're wrapping the root of the app in `` for simplicity, but this means that all transitions in the app will be animated, which can lead to unexpected animations.
+
+To fix, we're wrapping route children with `"none"` so each page can control its own animation:
+
+```js
+// Layout.js
+
+ {children}
+
+```
+
+In practice, navigations should be done via "enter" and "exit" props, or by using Transition Types.
+
+
+
+### Customizing animations {/*customizing-animations*/}
+
+By default, `` includes the default cross-fade from the browser.
+
+To customize animations, you can provide props to the `` component to specify which animations to use, based on [how the `` activates](/reference/react/ViewTransition#props).
+
+For example, we can slow down the `default` cross fade animation:
+
+```js
+
+
+```
+
+And define `slow-fade` in CSS using [view transition classes](/reference/react/ViewTransition#view-transition-class):
+
+```css
+::view-transition-old(.slow-fade) {
+ animation-duration: 500ms;
+}
+
+::view-transition-new(.slow-fade) {
+ animation-duration: 500ms;
+}
+```
+
+Now, the cross fade is slower:
+
+
+
+```js src/App.js active
+import { unstable_ViewTransition as ViewTransition } from "react";
+import Details from "./Details";
+import Home from "./Home";
+import { useRouter } from "./router";
+
+export default function App() {
+ const { url } = useRouter();
+
+ // Define a default animation of .slow-fade.
+ // See animations.css for the animation definition.
+ return (
+
+ {url === '/' ?
+ );
+}
+```
+
+```js src/Details.js hidden
+import { fetchVideo, fetchVideoDetails } from "./data";
+import { Thumbnail, VideoControls } from "./Videos";
+import { useRouter } from "./router";
+import Layout from "./Layout";
+import { use, Suspense } from "react";
+import { ChevronLeft } from "./Icons";
+
+function VideoInfo({ id }) {
+ const details = use(fetchVideoDetails(id));
+ return (
+ <>
+ {details.title}
+ {details.description}
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+
+
+
+
+ );
+}
+
+```
+
+```js src/Home.js hidden
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+ {count} Videos }>
+
+
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+ );
+}
+
+```
+
+```js src/Icons.js hidden
+export function ChevronLeft() {
+ return (
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js hidden
+import {unstable_ViewTransition as ViewTransition} from 'react'; import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+
+ return (
+
+
+
+ {heading}
+ {isPending &&
+
+ {/* Opt-out of ViewTransition for the content. */}
+ {/* Content can define it's own ViewTransition. */}
+
+
+
+
+ );
+}
+```
+
+```js src/LikeButton.js hidden
+import {useState} from 'react';
+import {Heart} from './Icons';
+
+// A hack since we don't actually have a backend.
+// Unlike local state, this survives videos being filtered.
+const likedVideos = new Set();
+
+export default function LikeButton({video}) {
+ const [isLiked, setIsLiked] = useState(() => likedVideos.has(video.id));
+ const [animate, setAnimate] = useState(false);
+ return (
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js hidden
+import { useState } from "react";
+import LikeButton from "./LikeButton";
+import { useRouter } from "./router";
+import { PauseIcon, PlayIcon } from "./Icons";
+import { startTransition } from "react";
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Thumbnail({ video, children }) {
+ return (
+
+ {children}
+
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ );
+}
+```
+
+
+```js src/data.js hidden
+const videos = [
+ {
+ id: '1',
+ title: 'First video',
+ description: 'Video description',
+ image: 'blue',
+ },
+ {
+ id: '2',
+ title: 'Second video',
+ description: 'Video description',
+ image: 'red',
+ },
+ {
+ id: '3',
+ title: 'Third video',
+ description: 'Video description',
+ image: 'green',
+ },
+ {
+ id: '4',
+ title: 'Fourth video',
+ description: 'Video description',
+ image: 'purple',
+ },
+ {
+ id: '5',
+ title: 'Fifth video',
+ description: 'Video description',
+ image: 'yellow',
+ },
+ {
+ id: '6',
+ title: 'Sixth video',
+ description: 'Video description',
+ image: 'gray',
+ },
+];
+
+let videosCache = new Map();
+let videoCache = new Map();
+let videoDetailsCache = new Map();
+const VIDEO_DELAY = 1;
+const VIDEO_DETAILS_DELAY = 1000;
+export function fetchVideos() {
+ if (videosCache.has(0)) {
+ return videosCache.get(0);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos);
+ }, VIDEO_DELAY);
+ });
+ videosCache.set(0, promise);
+ return promise;
+}
+
+export function fetchVideo(id) {
+ if (videoCache.has(id)) {
+ return videoCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DELAY);
+ });
+ videoCache.set(id, promise);
+ return promise;
+}
+
+export function fetchVideoDetails(id) {
+ if (videoDetailsCache.has(id)) {
+ return videoDetailsCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DETAILS_DELAY);
+ });
+ videoDetailsCache.set(id, promise);
+ return promise;
+}
+```
+
+```js src/router.js hidden
+import {
+ useState,
+ createContext,
+ use,
+ useTransition,
+ useLayoutEffect,
+ useEffect,
+} from "react";
+
+const RouterContext = createContext({ url: "/", params: {} });
+
+export function useRouter() {
+ return use(RouterContext);
+}
+
+export function useIsNavPending() {
+ return use(RouterContext).isPending;
+}
+
+export function Router({ children }) {
+ const [routerState, setRouterState] = useState({
+ pendingNav: () => {},
+ url: document.location.pathname,
+ });
+ const [isPending, startTransition] = useTransition();
+
+ function go(url) {
+ setRouterState({
+ url,
+ pendingNav() {
+ window.history.pushState({}, "", url);
+ },
+ });
+ }
+ function navigate(url) {
+ // Update router state in transition.
+ startTransition(() => {
+ go(url);
+ });
+ }
+
+ function navigateBack(url) {
+ // Update router state in transition.
+ startTransition(() => {
+ go(url);
+ });
+ }
+
+ useEffect(() => {
+ function handlePopState() {
+ // This should not animate because restoration has to be synchronous.
+ // Even though it's a transition.
+ startTransition(() => {
+ setRouterState({
+ url: document.location.pathname + document.location.search,
+ pendingNav() {
+ // Noop. URL has already updated.
+ },
+ });
+ });
+ }
+ window.addEventListener("popstate", handlePopState);
+ return () => {
+ window.removeEventListener("popstate", handlePopState);
+ };
+ }, []);
+ const pendingNav = routerState.pendingNav;
+ useLayoutEffect(() => {
+ pendingNav();
+ }, [pendingNav]);
+
+ return (
+
+ {children}
+
+ );
+}
+```
+
+```css src/styles.css hidden
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+
+```css src/animations.css
+/* Define .slow-fade using view transition classes */
+::view-transition-old(.slow-fade) {
+ animation-duration: 500ms;
+}
+
+::view-transition-new(.slow-fade) {
+ animation-duration: 500ms;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+import './animations.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+See [Styling View Transitions](/reference/react/ViewTransition#styling-view-transitions) for a full guide on styling `
`.
+
+### Shared Element Transitions {/*shared-element-transitions*/}
+
+When two pages include the same element, often you want to animate it from one page to the next.
+
+To do this you can add a unique `name` to the ``:
+
+```js
+
+
+```
+
+Now the video thumbnail animates between the two pages:
+
+
+
+```js src/App.js
+import { unstable_ViewTransition as ViewTransition } from "react";
+import Details from "./Details";
+import Home from "./Home";
+import { useRouter } from "./router";
+
+export default function App() {
+ const { url } = useRouter();
+
+ // Keeping our default slow-fade.
+ // This allows the content not in the shared
+ // element transition to cross-fade.
+ return (
+
+ {url === "/" ?
+ );
+}
+```
+
+```js src/Details.js hidden
+import { fetchVideo, fetchVideoDetails } from "./data";
+import { Thumbnail, VideoControls } from "./Videos";
+import { useRouter } from "./router";
+import Layout from "./Layout";
+import { use, Suspense } from "react";
+import { ChevronLeft } from "./Icons";
+
+function VideoInfo({ id }) {
+ const details = use(fetchVideoDetails(id));
+ return (
+ <>
+ {details.title}
+ {details.description}
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+ }
+ >
+
+
+
+
+
+ );
+}
+
+```
+
+```js src/Home.js hidden
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+
{count} Videos
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js hidden
+import {unstable_ViewTransition as ViewTransition} from 'react'; import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+
+ return (
+
+
+
+ {heading}
+ {isPending &&
+
+ {/* Opt-out of ViewTransition for the content. */}
+ {/* Content can define it's own ViewTransition. */}
+
+
+
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js active
+import { useState, unstable_ViewTransition as ViewTransition } from "react"; import LikeButton from "./LikeButton"; import { useRouter } from "./router"; import { PauseIcon, PlayIcon } from "./Icons"; import { startTransition } from "react";
+
+export function Thumbnail({ video, children }) {
+ // Add a name to animate with a shared element transition.
+ // This uses the default animation, no additional css needed.
+ return (
+
+
+ {children}
+
+
+ );
+}
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ {children}
+
+ );
+}
+```
+
+```css src/styles.css hidden
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+
+```css src/animations.css
+/* No additional animations needed */
+
+
+
+
+
+
+
+
+
+/* Previously defined animations below */
+
+
+
+
+
+::view-transition-old(.slow-fade) {
+ animation-duration: 500ms;
+}
+
+::view-transition-new(.slow-fade) {
+ animation-duration: 500ms;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+import './animations.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+By default, React automatically generates a unique `name` for each element activated for a transition (see [How does `` work](/reference/react/ViewTransition#how-does-viewtransition-work)). When React sees a transition where a `` with a `name` is removed and a new `` with the same `name` is added, it will activate a shared element transition.
+
+For more info, see the docs for [Animating a Shared Element](/reference/react/ViewTransition#animating-a-shared-element).
+
+### Animating based on cause {/*animating-based-on-cause*/}
+
+Sometimes, you may want elements to animate differently based on how it was triggered. For this use case, we've added a new API called `addTransitionType` to specify the cause of a transition:
+
+```js {4,11}
+function navigate(url) {
+ startTransition(() => {
+ // Transition type for the cause "nav forward"
+ addTransitionType('nav-forward');
+ go(url);
+ });
+}
+function navigateBack(url) {
+ startTransition(() => {
+ // Transition type for the cause "nav backward"
+ addTransitionType('nav-back');
+ go(url);
+ });
+}
+```
+
+With transition types, you can provide custom animations via props to ``. Let's add a shared element transition to the header for "6 Videos" and "Back":
+
+```js {4,5}
+
+ {heading}
+
+```
+
+Here we pass a `share` prop to define how to animate based on the transition type. When the share transition activates from `nav-forward`, the view transition class `slide-forward` is applied. When it's from `nav-back`, the `slide-back` animation is activated. Let's define these animations in CSS:
+
+```css
+::view-transition-old(.slide-forward) {
+ /* when sliding forward, the "old" page should slide out to left. */
+ animation: ...
+}
+
+::view-transition-new(.slide-forward) {
+ /* when sliding forward, the "new" page should slide in from right. */
+ animation: ...
+}
+
+::view-transition-old(.slide-back) {
+ /* when sliding back, the "old" page should slide out to right. */
+ animation: ...
+}
+
+::view-transition-new(.slide-back) {
+ /* when sliding back, the "new" page should slide in from left. */
+ animation: ...
+}
+```
+
+Now we can animate the header along with thumbnail based on navigation type:
+
+
+
+```js src/App.js hidden
+import { unstable_ViewTransition as ViewTransition } from "react";
+import Details from "./Details";
+import Home from "./Home";
+import { useRouter } from "./router";
+
+export default function App() {
+ const { url } = useRouter();
+
+ // Keeping our default slow-fade.
+ return (
+
+ {url === "/" ?
+ );
+}
+```
+
+```js src/Details.js hidden
+import { fetchVideo, fetchVideoDetails } from "./data";
+import { Thumbnail, VideoControls } from "./Videos";
+import { useRouter } from "./router";
+import Layout from "./Layout";
+import { use, Suspense } from "react";
+import { ChevronLeft } from "./Icons";
+
+function VideoInfo({ id }) {
+ const details = use(fetchVideoDetails(id));
+ return (
+ <>
+ {details.title}
+ {details.description}
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+
+
+
+
+ );
+}
+
+```
+
+```js src/Home.js hidden
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+ {count} Videos
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js active
+import {unstable_ViewTransition as ViewTransition} from 'react'; import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+ return (
+
+
+
+ {/* Custom classes based on transition type. */}
+
+ {heading}
+
+ {isPending &&
+
+ {/* Opt-out of ViewTransition for the content. */}
+ {/* Content can define it's own ViewTransition. */}
+
+
+
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js hidden
+import { useState, unstable_ViewTransition as ViewTransition } from "react";
+import LikeButton from "./LikeButton";
+import { useRouter } from "./router";
+import { PauseIcon, PlayIcon } from "./Icons";
+import { startTransition } from "react";
+
+export function Thumbnail({ video, children }) {
+ // Add a name to animate with a shared element transition.
+ // This uses the default animation, no additional css needed.
+ return (
+
+
+ {children}
+
+
+ );
+}
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ {children}
+
+ );
+}
+
+const RouterContext = createContext({ url: "/", params: {} });
+
+export function useRouter() {
+ return use(RouterContext);
+}
+
+export function useIsNavPending() {
+ return use(RouterContext).isPending;
+}
+
+```
+
+```css src/styles.css hidden
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+
+```css src/animations.css
+/* Animations for view transition classed added by transition type */
+::view-transition-old(.slide-forward) {
+ /* when sliding forward, the "old" page should slide out to left. */
+ animation: 150ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-left;
+}
+
+::view-transition-new(.slide-forward) {
+ /* when sliding forward, the "new" page should slide in from right. */
+ animation: 210ms cubic-bezier(0, 0, 0.2, 1) 150ms both fade-in,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-right;
+}
+
+::view-transition-old(.slide-back) {
+ /* when sliding back, the "old" page should slide out to right. */
+ animation: 150ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-right;
+}
+
+::view-transition-new(.slide-back) {
+ /* when sliding back, the "new" page should slide in from left. */
+ animation: 210ms cubic-bezier(0, 0, 0.2, 1) 150ms both fade-in,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-left;
+}
+
+/* New keyframes to support our animations above. */
+@keyframes fade-in {
+ from {
+ opacity: 0;
+ }
+}
+
+@keyframes fade-out {
+ to {
+ opacity: 0;
+ }
+}
+
+@keyframes slide-to-right {
+ to {
+ transform: translateX(50px);
+ }
+}
+
+@keyframes slide-from-right {
+ from {
+ transform: translateX(50px);
+ }
+ to {
+ transform: translateX(0);
+ }
+}
+
+@keyframes slide-to-left {
+ to {
+ transform: translateX(-50px);
+ }
+}
+
+@keyframes slide-from-left {
+ from {
+ transform: translateX(-50px);
+ }
+ to {
+ transform: translateX(0);
+ }
+}
+
+/* Previously defined animations. */
+
+/* Default .slow-fade. */
+::view-transition-old(.slow-fade) {
+ animation-duration: 500ms;
+}
+
+::view-transition-new(.slow-fade) {
+ animation-duration: 500ms;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+import './animations.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+### Animating Suspense Boundaries {/*animating-suspense-boundaries*/}
+
+Suspense will also activate View Transitions.
+
+To animate the fallback to content, we can wrap `Suspense` with ``:
+
+```js
+
+
+```
+
+By adding this, the fallback will cross-fade into the content. Click a video and see the video info animate in:
+
+
+
+```js src/App.js hidden
+import { unstable_ViewTransition as ViewTransition } from "react";
+import Details from "./Details";
+import Home from "./Home";
+import { useRouter } from "./router";
+
+export default function App() {
+ const { url } = useRouter();
+
+ // Default slow-fade animation.
+ return (
+
+ {url === "/" ?
+ );
+}
+```
+
+```js src/Details.js active
+import { use, Suspense, unstable_ViewTransition as ViewTransition } from "react"; import { fetchVideo, fetchVideoDetails } from "./data"; import { Thumbnail, VideoControls } from "./Videos"; import { useRouter } from "./router"; import Layout from "./Layout"; import { ChevronLeft } from "./Icons";
+
+function VideoDetails({ id }) {
+ // Cross-fade the fallback to content.
+ return (
+
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+ }
+ >
+
+
+
+
+
+ );
+}
+
+function VideoInfo({ id }) {
+ const details = use(fetchVideoDetails(id));
+ return (
+
+
{details.title}
+
{details.description}
+
+ );
+}
+```
+
+```js src/Home.js hidden
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+
{count} Videos }>
+
+
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+ );
+}
+
+```
+
+```js src/Icons.js hidden
+export function ChevronLeft() {
+ return (
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js hidden
+import {unstable_ViewTransition as ViewTransition} from 'react';
+import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+ return (
+
+
+
+ {/* Custom classes based on transition type. */}
+
+ {heading}
+
+ {isPending &&
+
+ {/* Opt-out of ViewTransition for the content. */}
+ {/* Content can define it's own ViewTransition. */}
+
+
+
+
+ );
+}
+```
+
+```js src/LikeButton.js hidden
+import {useState} from 'react';
+import {Heart} from './Icons';
+
+// A hack since we don't actually have a backend.
+// Unlike local state, this survives videos being filtered.
+const likedVideos = new Set();
+
+export default function LikeButton({video}) {
+ const [isLiked, setIsLiked] = useState(() => likedVideos.has(video.id));
+ const [animate, setAnimate] = useState(false);
+ return (
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js hidden
+import { useState, unstable_ViewTransition as ViewTransition } from "react";
+import LikeButton from "./LikeButton";
+import { useRouter } from "./router";
+import { PauseIcon, PlayIcon } from "./Icons";
+import { startTransition } from "react";
+
+export function Thumbnail({ video, children }) {
+ // Add a name to animate with a shared element transition.
+ // This uses the default animation, no additional css needed.
+ return (
+
+
+ {children}
+
+
+ );
+}
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ );
+}
+```
+
+
+```js src/data.js hidden
+const videos = [
+ {
+ id: '1',
+ title: 'First video',
+ description: 'Video description',
+ image: 'blue',
+ },
+ {
+ id: '2',
+ title: 'Second video',
+ description: 'Video description',
+ image: 'red',
+ },
+ {
+ id: '3',
+ title: 'Third video',
+ description: 'Video description',
+ image: 'green',
+ },
+ {
+ id: '4',
+ title: 'Fourth video',
+ description: 'Video description',
+ image: 'purple',
+ },
+ {
+ id: '5',
+ title: 'Fifth video',
+ description: 'Video description',
+ image: 'yellow',
+ },
+ {
+ id: '6',
+ title: 'Sixth video',
+ description: 'Video description',
+ image: 'gray',
+ },
+];
+
+let videosCache = new Map();
+let videoCache = new Map();
+let videoDetailsCache = new Map();
+const VIDEO_DELAY = 1;
+const VIDEO_DETAILS_DELAY = 1000;
+export function fetchVideos() {
+ if (videosCache.has(0)) {
+ return videosCache.get(0);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos);
+ }, VIDEO_DELAY);
+ });
+ videosCache.set(0, promise);
+ return promise;
+}
+
+export function fetchVideo(id) {
+ if (videoCache.has(id)) {
+ return videoCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DELAY);
+ });
+ videoCache.set(id, promise);
+ return promise;
+}
+
+export function fetchVideoDetails(id) {
+ if (videoDetailsCache.has(id)) {
+ return videoDetailsCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DETAILS_DELAY);
+ });
+ videoDetailsCache.set(id, promise);
+ return promise;
+}
+```
+
+```js src/router.js hidden
+import {useState, createContext, use, useTransition, useLayoutEffect, useEffect, unstable_addTransitionType as addTransitionType} from "react";
+
+export function Router({ children }) {
+ const [isPending, startTransition] = useTransition();
+ const [routerState, setRouterState] = useState({pendingNav: () => {}, url: document.location.pathname});
+ function navigate(url) {
+ startTransition(() => {
+ // Transition type for the cause "nav forward"
+ addTransitionType('nav-forward');
+ go(url);
+ });
+ }
+ function navigateBack(url) {
+ startTransition(() => {
+ // Transition type for the cause "nav backward"
+ addTransitionType('nav-back');
+ go(url);
+ });
+ }
+
+ function go(url) {
+ setRouterState({
+ url,
+ pendingNav() {
+ window.history.pushState({}, "", url);
+ },
+ });
+ }
+
+ useEffect(() => {
+ function handlePopState() {
+ // This should not animate because restoration has to be synchronous.
+ // Even though it's a transition.
+ startTransition(() => {
+ setRouterState({
+ url: document.location.pathname + document.location.search,
+ pendingNav() {
+ // Noop. URL has already updated.
+ },
+ });
+ });
+ }
+ window.addEventListener("popstate", handlePopState);
+ return () => {
+ window.removeEventListener("popstate", handlePopState);
+ };
+ }, []);
+ const pendingNav = routerState.pendingNav;
+ useLayoutEffect(() => {
+ pendingNav();
+ }, [pendingNav]);
+
+ return (
+
+ {children}
+
+ );
+}
+
+const RouterContext = createContext({ url: "/", params: {} });
+
+export function useRouter() {
+ return use(RouterContext);
+}
+
+export function useIsNavPending() {
+ return use(RouterContext).isPending;
+}
+
+```
+
+```css src/styles.css hidden
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+
+```css src/animations.css
+/* Slide the fallback down */
+::view-transition-old(.slide-down) {
+ animation: 150ms ease-out both fade-out, 150ms ease-out both slide-down;
+}
+
+/* Slide the content up */
+::view-transition-new(.slide-up) {
+ animation: 210ms ease-in 150ms both fade-in, 400ms ease-in both slide-up;
+}
+
+/* Define the new keyframes */
+@keyframes slide-up {
+ from {
+ transform: translateY(10px);
+ }
+ to {
+ transform: translateY(0);
+ }
+}
+
+@keyframes slide-down {
+ from {
+ transform: translateY(0);
+ }
+ to {
+ transform: translateY(10px);
+ }
+}
+
+/* Previously defined animations below */
+
+/* Animations for view transition classed added by transition type */
+::view-transition-old(.slide-forward) {
+ /* when sliding forward, the "old" page should slide out to left. */
+ animation: 150ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-left;
+}
+
+::view-transition-new(.slide-forward) {
+ /* when sliding forward, the "new" page should slide in from right. */
+ animation: 210ms cubic-bezier(0, 0, 0.2, 1) 150ms both fade-in,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-right;
+}
+
+::view-transition-old(.slide-back) {
+ /* when sliding back, the "old" page should slide out to right. */
+ animation: 150ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-right;
+}
+
+::view-transition-new(.slide-back) {
+ /* when sliding back, the "new" page should slide in from left. */
+ animation: 210ms cubic-bezier(0, 0, 0.2, 1) 150ms both fade-in,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-left;
+}
+
+/* Keyframes to support our animations above. */
+@keyframes fade-in {
+ from {
+ opacity: 0;
+ }
+}
+
+@keyframes fade-out {
+ to {
+ opacity: 0;
+ }
+}
+
+@keyframes slide-to-right {
+ to {
+ transform: translateX(50px);
+ }
+}
+
+@keyframes slide-from-right {
+ from {
+ transform: translateX(50px);
+ }
+ to {
+ transform: translateX(0);
+ }
+}
+
+@keyframes slide-to-left {
+ to {
+ transform: translateX(-50px);
+ }
+}
+
+@keyframes slide-from-left {
+ from {
+ transform: translateX(-50px);
+ }
+ to {
+ transform: translateX(0);
+ }
+}
+
+/* Default .slow-fade. */
+::view-transition-old(.slow-fade) {
+ animation-duration: 500ms;
+}
+
+::view-transition-new(.slow-fade) {
+ animation-duration: 500ms;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+import './animations.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+We can also provide custom animations using an `exit` on the fallback, and `enter` on the content:
+
+```js {3,8}
+
+
+
+
+```
+
+Here's how we'll define `slide-down` and `slide-up` with CSS:
+
+```css {1, 6}
+::view-transition-old(.slide-down) {
+ /* Slide the fallback down */
+ animation: ...;
+}
+
+::view-transition-new(.slide-up) {
+ /* Slide the content up */
+ animation: ...;
+}
+```
+
+Now, the Suspense content replaces the fallback with a sliding animation:
+
+
+
+```js src/App.js hidden
+import { unstable_ViewTransition as ViewTransition } from "react";
+import Details from "./Details";
+import Home from "./Home";
+import { useRouter } from "./router";
+
+export default function App() {
+ const { url } = useRouter();
+
+ // Default slow-fade animation.
+ return (
+
+ {url === "/" ?
+ );
+}
+```
+
+```js src/Details.js active
+import { use, Suspense, unstable_ViewTransition as ViewTransition } from "react"; import { fetchVideo, fetchVideoDetails } from "./data"; import { Thumbnail, VideoControls } from "./Videos"; import { useRouter } from "./router"; import Layout from "./Layout"; import { ChevronLeft } from "./Icons";
+
+function VideoDetails({ id }) {
+ return (
+
+
+
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+ {
+ navigateBack("/");
+ }}
+ >
+
+ }
+ >
+
+
+
+
+
+ );
+}
+
+function VideoInfo({ id }) {
+ const details = use(fetchVideoDetails(id));
+ return (
+ <>
+
{details.title}
+
{details.description}
+
+ );
+}
+```
+
+```js src/Home.js hidden
+import { Video } from "./Videos";
+import Layout from "./Layout";
+import { fetchVideos } from "./data";
+import { useId, useState, use } from "react";
+import { IconSearch } from "./Icons";
+
+function SearchInput({ value, onChange }) {
+ const id = useId();
+ return (
+
+ );
+}
+
+function filterVideos(videos, query) {
+ const keywords = query
+ .toLowerCase()
+ .split(" ")
+ .filter((s) => s !== "");
+ if (keywords.length === 0) {
+ return videos;
+ }
+ return videos.filter((video) => {
+ const words = (video.title + " " + video.description)
+ .toLowerCase()
+ .split(" ");
+ return keywords.every((kw) => words.some((w) => w.includes(kw)));
+ });
+}
+
+export default function Home() {
+ const videos = use(fetchVideos());
+ const count = videos.length;
+ const [searchText, setSearchText] = useState("");
+ const foundVideos = filterVideos(videos, searchText);
+ return (
+
{count} Videos }>
+
+
+ {foundVideos.length === 0 && (
+
No results
+ )}
+
+ {foundVideos.map((video) => (
+
+
+
+ );
+}
+
+```
+
+```js src/Icons.js hidden
+export function ChevronLeft() {
+ return (
+
+
+
+
+ );
+}
+
+export function PauseIcon() {
+ return (
+
+
+ );
+}
+
+export function PlayIcon() {
+ return (
+
+
+ );
+}
+export function Heart({liked, animate}) {
+ return (
+ <>
+
+
+
+
+ {liked ? (
+
+
+ );
+}
+
+export function IconSearch(props) {
+ return (
+
+
+ );
+}
+```
+
+```js src/Layout.js hidden
+import {unstable_ViewTransition as ViewTransition} from 'react';
+import { useIsNavPending } from "./router";
+
+export default function Page({ heading, children }) {
+ const isPending = useIsNavPending();
+ return (
+
+
+
+ {/* Custom classes based on transition type. */}
+
+ {heading}
+
+ {isPending &&
+
+ {/* Opt-out of ViewTransition for the content. */}
+ {/* Content can define it's own ViewTransition. */}
+
+
+
+
+ );
+}
+```
+
+```js src/LikeButton.js hidden
+import {useState} from 'react';
+import {Heart} from './Icons';
+
+// A hack since we don't actually have a backend.
+// Unlike local state, this survives videos being filtered.
+const likedVideos = new Set();
+
+export default function LikeButton({video}) {
+ const [isLiked, setIsLiked] = useState(() => likedVideos.has(video.id));
+ const [animate, setAnimate] = useState(false);
+ return (
+
{
+ const nextIsLiked = !isLiked;
+ if (nextIsLiked) {
+ likedVideos.add(video.id);
+ } else {
+ likedVideos.delete(video.id);
+ }
+ setAnimate(true);
+ setIsLiked(nextIsLiked);
+ }}>
+
+ );
+}
+```
+
+```js src/Videos.js hidden
+import { useState, unstable_ViewTransition as ViewTransition } from "react";
+import LikeButton from "./LikeButton";
+import { useRouter } from "./router";
+import { PauseIcon, PlayIcon } from "./Icons";
+import { startTransition } from "react";
+
+export function Thumbnail({ video, children }) {
+ // Add a name to animate with a shared element transition.
+ // This uses the default animation, no additional css needed.
+ return (
+
+
+ {children}
+
+
+ );
+}
+
+export function VideoControls() {
+ const [isPlaying, setIsPlaying] = useState(false);
+
+ return (
+
+ startTransition(() => {
+ setIsPlaying((p) => !p);
+ })
+ }
+ >
+ {isPlaying ?
+ );
+}
+
+export function Video({ video }) {
+ const { navigate } = useRouter();
+
+ return (
+
+
{
+ e.preventDefault();
+ navigate(`/video/${video.id}`);
+ }}
+ >
+
+
+
+
{video.title}
+
{video.description}
+
+
+
+
+ );
+}
+```
+
+
+```js src/data.js hidden
+const videos = [
+ {
+ id: '1',
+ title: 'First video',
+ description: 'Video description',
+ image: 'blue',
+ },
+ {
+ id: '2',
+ title: 'Second video',
+ description: 'Video description',
+ image: 'red',
+ },
+ {
+ id: '3',
+ title: 'Third video',
+ description: 'Video description',
+ image: 'green',
+ },
+ {
+ id: '4',
+ title: 'Fourth video',
+ description: 'Video description',
+ image: 'purple',
+ },
+ {
+ id: '5',
+ title: 'Fifth video',
+ description: 'Video description',
+ image: 'yellow',
+ },
+ {
+ id: '6',
+ title: 'Sixth video',
+ description: 'Video description',
+ image: 'gray',
+ },
+];
+
+let videosCache = new Map();
+let videoCache = new Map();
+let videoDetailsCache = new Map();
+const VIDEO_DELAY = 1;
+const VIDEO_DETAILS_DELAY = 1000;
+export function fetchVideos() {
+ if (videosCache.has(0)) {
+ return videosCache.get(0);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos);
+ }, VIDEO_DELAY);
+ });
+ videosCache.set(0, promise);
+ return promise;
+}
+
+export function fetchVideo(id) {
+ if (videoCache.has(id)) {
+ return videoCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DELAY);
+ });
+ videoCache.set(id, promise);
+ return promise;
+}
+
+export function fetchVideoDetails(id) {
+ if (videoDetailsCache.has(id)) {
+ return videoDetailsCache.get(id);
+ }
+ const promise = new Promise((resolve) => {
+ setTimeout(() => {
+ resolve(videos.find((video) => video.id === id));
+ }, VIDEO_DETAILS_DELAY);
+ });
+ videoDetailsCache.set(id, promise);
+ return promise;
+}
+```
+
+```js src/router.js hidden
+import {useState, createContext, use, useTransition, useLayoutEffect, useEffect, unstable_addTransitionType as addTransitionType} from "react";
+
+export function Router({ children }) {
+ const [isPending, startTransition] = useTransition();
+ const [routerState, setRouterState] = useState({pendingNav: () => {}, url: document.location.pathname});
+ function navigate(url) {
+ startTransition(() => {
+ // Transition type for the cause "nav forward"
+ addTransitionType('nav-forward');
+ go(url);
+ });
+ }
+ function navigateBack(url) {
+ startTransition(() => {
+ // Transition type for the cause "nav backward"
+ addTransitionType('nav-back');
+ go(url);
+ });
+ }
+
+ function go(url) {
+ setRouterState({
+ url,
+ pendingNav() {
+ window.history.pushState({}, "", url);
+ },
+ });
+ }
+
+ useEffect(() => {
+ function handlePopState() {
+ // This should not animate because restoration has to be synchronous.
+ // Even though it's a transition.
+ startTransition(() => {
+ setRouterState({
+ url: document.location.pathname + document.location.search,
+ pendingNav() {
+ // Noop. URL has already updated.
+ },
+ });
+ });
+ }
+ window.addEventListener("popstate", handlePopState);
+ return () => {
+ window.removeEventListener("popstate", handlePopState);
+ };
+ }, []);
+ const pendingNav = routerState.pendingNav;
+ useLayoutEffect(() => {
+ pendingNav();
+ }, [pendingNav]);
+
+ return (
+
+ {children}
+
+ );
+}
+
+const RouterContext = createContext({ url: "/", params: {} });
+
+export function useRouter() {
+ return use(RouterContext);
+}
+
+export function useIsNavPending() {
+ return use(RouterContext).isPending;
+}
+
+```
+
+```css src/styles.css hidden
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Rg.woff2) format("woff2");
+ font-weight: 400;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Md.woff2) format("woff2");
+ font-weight: 500;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 600;
+ font-style: normal;
+ font-display: swap;
+}
+
+@font-face {
+ font-family: Optimistic Text;
+ src: url(https://react.dev/fonts/Optimistic_Text_W_Bd.woff2) format("woff2");
+ font-weight: 700;
+ font-style: normal;
+ font-display: swap;
+}
+
+* {
+ box-sizing: border-box;
+}
+
+html {
+ background-image: url(https://react.dev/images/meta-gradient-dark.png);
+ background-size: 100%;
+ background-position: -100%;
+ background-color: rgb(64 71 86);
+ background-repeat: no-repeat;
+ height: 100%;
+ width: 100%;
+}
+
+body {
+ font-family: Optimistic Text, -apple-system, ui-sans-serif, system-ui, sans-serif, Apple Color Emoji, Segoe UI Emoji, Segoe UI Symbol, Noto Color Emoji;
+ padding: 10px 0 10px 0;
+ margin: 0;
+ display: flex;
+ justify-content: center;
+}
+
+#root {
+ flex: 1 1;
+ height: auto;
+ background-color: #fff;
+ border-radius: 10px;
+ max-width: 450px;
+ min-height: 600px;
+ padding-bottom: 10px;
+}
+
+h1 {
+ margin-top: 0;
+ font-size: 22px;
+}
+
+h2 {
+ margin-top: 0;
+ font-size: 20px;
+}
+
+h3 {
+ margin-top: 0;
+ font-size: 18px;
+}
+
+h4 {
+ margin-top: 0;
+ font-size: 16px;
+}
+
+h5 {
+ margin-top: 0;
+ font-size: 14px;
+}
+
+h6 {
+ margin-top: 0;
+ font-size: 12px;
+}
+
+code {
+ font-size: 1.2em;
+}
+
+ul {
+ padding-inline-start: 20px;
+}
+
+.sr-only {
+ position: absolute;
+ width: 1px;
+ height: 1px;
+ padding: 0;
+ margin: -1px;
+ overflow: hidden;
+ clip: rect(0, 0, 0, 0);
+ white-space: nowrap;
+ border-width: 0;
+}
+
+.absolute {
+ position: absolute;
+}
+
+.overflow-visible {
+ overflow: visible;
+}
+
+.visible {
+ overflow: visible;
+}
+
+.fit {
+ width: fit-content;
+}
+
+
+/* Layout */
+.page {
+ display: flex;
+ flex-direction: column;
+ height: 100%;
+}
+
+.top-hero {
+ height: 200px;
+ display: flex;
+ justify-content: center;
+ align-items: center;
+ background-image: conic-gradient(
+ from 90deg at -10% 100%,
+ #2b303b 0deg,
+ #2b303b 90deg,
+ #16181d 1turn
+ );
+}
+
+.bottom {
+ flex: 1;
+ overflow: auto;
+}
+
+.top-nav {
+ display: flex;
+ align-items: center;
+ justify-content: space-between;
+ margin-bottom: 0;
+ padding: 0 12px;
+ top: 0;
+ width: 100%;
+ height: 44px;
+ color: #23272f;
+ font-weight: 700;
+ font-size: 20px;
+ z-index: 100;
+ cursor: default;
+}
+
+.content {
+ padding: 0 12px;
+ margin-top: 4px;
+}
+
+
+.loader {
+ color: #23272f;
+ font-size: 3px;
+ width: 1em;
+ margin-right: 18px;
+ height: 1em;
+ border-radius: 50%;
+ position: relative;
+ text-indent: -9999em;
+ animation: loading-spinner 1.3s infinite linear;
+ animation-delay: 200ms;
+ transform: translateZ(0);
+}
+
+@keyframes loading-spinner {
+ 0%,
+ 100% {
+ box-shadow: 0 -3em 0 0.2em,
+ 2em -2em 0 0em, 3em 0 0 -1em,
+ 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 0;
+ }
+ 12.5% {
+ box-shadow: 0 -3em 0 0, 2em -2em 0 0.2em,
+ 3em 0 0 0, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 25% {
+ box-shadow: 0 -3em 0 -0.5em,
+ 2em -2em 0 0, 3em 0 0 0.2em,
+ 2em 2em 0 0, 0 3em 0 -1em,
+ -2em 2em 0 -1em, -3em 0 0 -1em,
+ -2em -2em 0 -1em;
+ }
+ 37.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 0, 2em 2em 0 0.2em, 0 3em 0 0em,
+ -2em 2em 0 -1em, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 50% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 0em, 0 3em 0 0.2em,
+ -2em 2em 0 0, -3em 0em 0 -1em, -2em -2em 0 -1em;
+ }
+ 62.5% {
+ box-shadow: 0 -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 0,
+ -2em 2em 0 0.2em, -3em 0 0 0, -2em -2em 0 -1em;
+ }
+ 75% {
+ box-shadow: 0em -3em 0 -1em, 2em -2em 0 -1em,
+ 3em 0em 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0.2em, -2em -2em 0 0;
+ }
+ 87.5% {
+ box-shadow: 0em -3em 0 0, 2em -2em 0 -1em,
+ 3em 0 0 -1em, 2em 2em 0 -1em, 0 3em 0 -1em,
+ -2em 2em 0 0, -3em 0em 0 0, -2em -2em 0 0.2em;
+ }
+}
+
+/* LikeButton */
+.like-button {
+ outline-offset: 2px;
+ position: relative;
+ display: flex;
+ align-items: center;
+ justify-content: center;
+ width: 2.5rem;
+ height: 2.5rem;
+ cursor: pointer;
+ border-radius: 9999px;
+ border: none;
+ outline: none 2px;
+ color: #5e687e;
+ background: none;
+}
+
+.like-button:focus {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+}
+
+.like-button:active {
+ color: #a6423a;
+ background-color: rgba(166, 66, 58, .05);
+ transform: scaleX(0.95) scaleY(0.95);
+}
+
+.like-button:hover {
+ background-color: #f6f7f9;
+}
+
+.like-button.liked {
+ color: #a6423a;
+}
+
+/* Icons */
+@keyframes circle {
+ 0% {
+ transform: scale(0);
+ stroke-width: 16px;
+ }
+
+ 50% {
+ transform: scale(.5);
+ stroke-width: 16px;
+ }
+
+ to {
+ transform: scale(1);
+ stroke-width: 0;
+ }
+}
+
+.circle {
+ color: rgba(166, 66, 58, .5);
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4,0,.2,1);
+}
+
+.circle.liked.animate {
+ animation: circle .3s forwards;
+}
+
+.heart {
+ width: 1.5rem;
+ height: 1.5rem;
+}
+
+.heart.liked {
+ transform-origin: center;
+ transition-property: all;
+ transition-duration: .15s;
+ transition-timing-function: cubic-bezier(.4, 0, .2, 1);
+}
+
+.heart.liked.animate {
+ animation: scale .35s ease-in-out forwards;
+}
+
+.control-icon {
+ color: hsla(0, 0%, 100%, .5);
+ filter: drop-shadow(0 20px 13px rgba(0, 0, 0, .03)) drop-shadow(0 8px 5px rgba(0, 0, 0, .08));
+}
+
+.chevron-left {
+ margin-top: 2px;
+ rotate: 90deg;
+}
+
+
+/* Video */
+.thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 8rem;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.thumbnail.blue {
+ background-image: conic-gradient(at top right, #c76a15, #087ea4, #2b3491);
+}
+
+.thumbnail.red {
+ background-image: conic-gradient(at top right, #c76a15, #a6423a, #2b3491);
+}
+
+.thumbnail.green {
+ background-image: conic-gradient(at top right, #c76a15, #388f7f, #2b3491);
+}
+
+.thumbnail.purple {
+ background-image: conic-gradient(at top right, #c76a15, #575fb7, #2b3491);
+}
+
+.thumbnail.yellow {
+ background-image: conic-gradient(at top right, #c76a15, #FABD62, #2b3491);
+}
+
+.thumbnail.gray {
+ background-image: conic-gradient(at top right, #c76a15, #4E5769, #2b3491);
+}
+
+.video {
+ display: flex;
+ flex-direction: row;
+ gap: 0.75rem;
+ align-items: center;
+}
+
+.video .link {
+ display: flex;
+ flex-direction: row;
+ flex: 1 1 0;
+ gap: 0.125rem;
+ outline-offset: 4px;
+ cursor: pointer;
+}
+
+.video .info {
+ display: flex;
+ flex-direction: column;
+ justify-content: center;
+ margin-left: 8px;
+ gap: 0.125rem;
+}
+
+.video .info:hover {
+ text-decoration: underline;
+}
+
+.video-title {
+ font-size: 15px;
+ line-height: 1.25;
+ font-weight: 700;
+ color: #23272f;
+}
+
+.video-description {
+ color: #5e687e;
+ font-size: 13px;
+}
+
+/* Details */
+.details .thumbnail {
+ position: relative;
+ aspect-ratio: 16 / 9;
+ display: flex;
+ overflow: hidden;
+ flex-direction: column;
+ justify-content: center;
+ align-items: center;
+ border-radius: 0.5rem;
+ outline-offset: 2px;
+ width: 100%;
+ vertical-align: middle;
+ background-color: #ffffff;
+ background-size: cover;
+ user-select: none;
+}
+
+.video-details-title {
+ margin-top: 8px;
+}
+
+.video-details-speaker {
+ display: flex;
+ gap: 8px;
+ margin-top: 10px
+}
+
+.back {
+ display: flex;
+ align-items: center;
+ margin-left: -5px;
+ cursor: pointer;
+}
+
+.back:hover {
+ text-decoration: underline;
+}
+
+.info-title {
+ font-size: 1.5rem;
+ font-weight: 700;
+ line-height: 1.25;
+ margin: 8px 0 0 0 ;
+}
+
+.info-description {
+ margin: 8px 0 0 0;
+}
+
+.controls {
+ cursor: pointer;
+}
+
+.fallback {
+ background: #f6f7f8 linear-gradient(to right, #e6e6e6 5%, #cccccc 25%, #e6e6e6 35%) no-repeat;
+ background-size: 800px 104px;
+ display: block;
+ line-height: 1.25;
+ margin: 8px 0 0 0;
+ border-radius: 5px;
+ overflow: hidden;
+
+ animation: 1s linear 1s infinite shimmer;
+ animation-delay: 300ms;
+ animation-duration: 1s;
+ animation-fill-mode: forwards;
+ animation-iteration-count: infinite;
+ animation-name: shimmer;
+ animation-timing-function: linear;
+}
+
+
+.fallback.title {
+ width: 130px;
+ height: 30px;
+
+}
+
+.fallback.description {
+ width: 150px;
+ height: 21px;
+}
+
+@keyframes shimmer {
+ 0% {
+ background-position: -468px 0;
+ }
+
+ 100% {
+ background-position: 468px 0;
+ }
+}
+
+.search {
+ margin-bottom: 10px;
+}
+.search-input {
+ width: 100%;
+ position: relative;
+}
+
+.search-icon {
+ position: absolute;
+ top: 0;
+ bottom: 0;
+ inset-inline-start: 0;
+ display: flex;
+ align-items: center;
+ padding-inline-start: 1rem;
+ pointer-events: none;
+ color: #99a1b3;
+}
+
+.search-input input {
+ display: flex;
+ padding-inline-start: 2.75rem;
+ padding-top: 10px;
+ padding-bottom: 10px;
+ width: 100%;
+ text-align: start;
+ background-color: rgb(235 236 240);
+ outline: 2px solid transparent;
+ cursor: pointer;
+ border: none;
+ align-items: center;
+ color: rgb(35 39 47);
+ border-radius: 9999px;
+ vertical-align: middle;
+ font-size: 15px;
+}
+
+.search-input input:hover, .search-input input:active {
+ background-color: rgb(235 236 240/ 0.8);
+ color: rgb(35 39 47/ 0.8);
+}
+
+/* Home */
+.video-list {
+ position: relative;
+}
+
+.video-list .videos {
+ display: flex;
+ flex-direction: column;
+ gap: 1rem;
+ overflow-y: auto;
+ height: 100%;
+}
+```
+
+
+```css src/animations.css
+/* Slide the fallback down */
+::view-transition-old(.slide-down) {
+ animation: 150ms ease-out both fade-out, 150ms ease-out both slide-down;
+}
+
+/* Slide the content up */
+::view-transition-new(.slide-up) {
+ animation: 210ms ease-in 150ms both fade-in, 400ms ease-in both slide-up;
+}
+
+/* Define the new keyframes */
+@keyframes slide-up {
+ from {
+ transform: translateY(10px);
+ }
+ to {
+ transform: translateY(0);
+ }
+}
+
+@keyframes slide-down {
+ from {
+ transform: translateY(0);
+ }
+ to {
+ transform: translateY(10px);
+ }
+}
+
+/* Previously defined animations below */
+
+/* Animations for view transition classed added by transition type */
+::view-transition-old(.slide-forward) {
+ /* when sliding forward, the "old" page should slide out to left. */
+ animation: 150ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-left;
+}
+
+::view-transition-new(.slide-forward) {
+ /* when sliding forward, the "new" page should slide in from right. */
+ animation: 210ms cubic-bezier(0, 0, 0.2, 1) 150ms both fade-in,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-right;
+}
+
+::view-transition-old(.slide-back) {
+ /* when sliding back, the "old" page should slide out to right. */
+ animation: 150ms cubic-bezier(0.4, 0, 1, 1) both fade-out,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-to-right;
+}
+
+::view-transition-new(.slide-back) {
+ /* when sliding back, the "new" page should slide in from left. */
+ animation: 210ms cubic-bezier(0, 0, 0.2, 1) 150ms both fade-in,
+ 400ms cubic-bezier(0.4, 0, 0.2, 1) both slide-from-left;
+}
+
+/* Keyframes to support our animations above. */
+@keyframes fade-in {
+ from {
+ opacity: 0;
+ }
+}
+
+@keyframes fade-out {
+ to {
+ opacity: 0;
+ }
+}
+
+@keyframes slide-to-right {
+ to {
+ transform: translateX(50px);
+ }
+}
+
+@keyframes slide-from-right {
+ from {
+ transform: translateX(50px);
+ }
+ to {
+ transform: translateX(0);
+ }
+}
+
+@keyframes slide-to-left {
+ to {
+ transform: translateX(-50px);
+ }
+}
+
+@keyframes slide-from-left {
+ from {
+ transform: translateX(-50px);
+ }
+ to {
+ transform: translateX(0);
+ }
+}
+
+/* Default .slow-fade. */
+::view-transition-old(.slow-fade) {
+ animation-duration: 500ms;
+}
+
+::view-transition-new(.slow-fade) {
+ animation-duration: 500ms;
+}
+```
+
+```js src/index.js hidden
+import React, {StrictMode} from 'react';
+import {createRoot} from 'react-dom/client';
+import './styles.css';
+import './animations.css';
+
+import App from './App';
+import {Router} from './router';
+
+const root = createRoot(document.getElementById('root'));
+root.render(
+
+
+
+
+);
+```
+
+```json package.json hidden
+{
+ "dependencies": {
+ "react": "experimental",
+ "react-dom": "experimental",
+ "react-scripts": "latest"
+ },
+ "scripts": {
+ "start": "react-scripts start",
+ "build": "react-scripts build",
+ "test": "react-scripts test --env=jsdom",
+ "eject": "react-scripts eject"
+ }
+}
+```
+
+
+
+
+### Animating Lists {/*animating-lists*/}
+
+You can also use `
` to animate lists of items as they re-order, like in a searchable list of items:
+
+```js {3,5}
+
+ {filteredVideos.map((video) => (
+
+
+ ))}
+
+```
+
+To activate the ViewTransition, we can use `useDeferredValue`:
+
+```js {2}
+const [searchText, setSearchText] = useState('');
+const deferredSearchText = useDeferredValue(searchText);
+const filteredVideos = filterVideos(videos, deferredSearchText);
+```
+
+Now the items animate as you type in the search bar:
+
+
+
+```js src/App.js hidden
+import { unstable_ViewTransition as ViewTransition } from "react";
+import Details from "./Details";
+import Home from "./Home";
+import { useRouter } from "./router";
+
+export default function App() {
+ const { url } = useRouter();
+
+ // Default slow-fade animation.
+ return (
+
+ {url === "/" ?
+ );
+}
+```
+
+```js src/Details.js hidden
+import { use, Suspense, unstable_ViewTransition as ViewTransition } from "react";
+import { fetchVideo, fetchVideoDetails } from "./data";
+import { Thumbnail, VideoControls } from "./Videos";
+import { useRouter } from "./router";
+import Layout from "./Layout";
+import { ChevronLeft } from "./Icons";
+
+function VideoDetails({id}) {
+ // Animate from Suspense fallback to content
+ return (
+
+
+ }
+ >
+ {/* Animate the content up */}
+
+
+
+ );
+}
+
+function VideoInfoFallback() {
+ return (
+ <>
+
+
+
+ );
+}
+
+export default function Details() {
+ const { url, navigateBack } = useRouter();
+ const videoId = url.split("/").pop();
+ const video = use(fetchVideo(videoId));
+
+ return (
+
{
+ navigateBack("/");
+ }}
+ >
+ 
+ 
+ 
+ 
+