reactjs · yousufkalim · Oct 23, 2023 · Sep 25, 2023 · Sep 26, 2023 · Sep 26, 2023
diff --git a/package.json b/package.json
@@ -36,7 +36,7 @@
     "next-remote-watch": "^1.0.0",
     "parse-numeric-range": "^1.2.0",
     "react": "^0.0.0-experimental-16d053d59-20230506",
-    "react-collapsed": "npm:@gaearon/[email protected]",
+    "react-collapsed": "4.0.4",
     "react-dom": "^0.0.0-experimental-16d053d59-20230506",
     "remark-frontmatter": "^4.0.1",
     "remark-gfm": "^3.0.1"

diff --git a/public/images/docs/diagrams/conditional_render_tree.dark.png b/public/images/docs/diagrams/conditional_render_tree.dark.png
diff --git a/public/images/docs/diagrams/conditional_render_tree.png b/public/images/docs/diagrams/conditional_render_tree.png
diff --git a/public/images/docs/diagrams/generic_dependency_tree.dark.png b/public/images/docs/diagrams/generic_dependency_tree.dark.png
diff --git a/public/images/docs/diagrams/generic_dependency_tree.png b/public/images/docs/diagrams/generic_dependency_tree.png
diff --git a/public/images/docs/diagrams/generic_render_tree.dark.png b/public/images/docs/diagrams/generic_render_tree.dark.png
diff --git a/public/images/docs/diagrams/generic_render_tree.png b/public/images/docs/diagrams/generic_render_tree.png
diff --git a/public/images/docs/diagrams/module_dependency_tree.dark.png b/public/images/docs/diagrams/module_dependency_tree.dark.png
diff --git a/public/images/docs/diagrams/module_dependency_tree.png b/public/images/docs/diagrams/module_dependency_tree.png
diff --git a/public/images/docs/diagrams/render_tree.dark.png b/public/images/docs/diagrams/render_tree.dark.png
diff --git a/public/images/docs/diagrams/render_tree.png b/public/images/docs/diagrams/render_tree.png
diff --git a/src/components/Layout/Sidebar/SidebarRouteTree.tsx b/src/components/Layout/Sidebar/SidebarRouteTree.tsx
@@ -7,7 +7,7 @@ import {useRef, useLayoutEffect, Fragment} from 'react';
 import cn from 'classnames';
 import {useRouter} from 'next/router';
 import {SidebarLink} from './SidebarLink';
-import useCollapse from 'react-collapsed';
+import {useCollapse} from 'react-collapsed';
 import usePendingRoute from 'hooks/usePendingRoute';
 import type {RouteItem} from 'components/Layout/getRouteMeta';
 

diff --git a/src/components/Seo.tsx b/src/components/Seo.tsx
@@ -22,6 +22,7 @@ const deployedTranslations = [
   'zh-hans',
   'es',
   'fr',
+  'ja',
   // We'll add more languages when they have enough content.
   // Please DO NOT edit this list without a discussion in the reactjs/react.dev repo.
   // It must be the same between all translations.

diff --git a/src/content/blog/2022/06/15/react-labs-what-we-have-been-working-on-june-2022.md b/src/content/blog/2022/06/15/react-labs-what-we-have-been-working-on-june-2022.md
@@ -8,7 +8,7 @@ June 15, 2022 by [Andrew Clark](https://twitter.com/acdlite), [Dan Abramov](http
 
 <Intro>
 
-[React 18](https://reactjs.org/blog/2022/03/29/react-v18) was years in the making, and with it brought valuable lessons for the React team. Its release was the result of many years of research and exploring many paths. Some of those paths were successful; many more were dead-ends that led to new insights. One lesson we’ve learned is that it’s frustrating for the community to wait for new features without having insight into these paths that we’re exploring.
+[React 18](https://react.dev/blog/2022/03/29/react-v18) was years in the making, and with it brought valuable lessons for the React team. Its release was the result of many years of research and exploring many paths. Some of those paths were successful; many more were dead-ends that led to new insights. One lesson we’ve learned is that it’s frustrating for the community to wait for new features without having insight into these paths that we’re exploring.
 
 </Intro>
 

diff --git a/src/content/community/conferences.md b/src/content/community/conferences.md
@@ -61,7 +61,6 @@ October 27th 2023. In-person in Verona, Italy and online (hybrid event)
 
 [Website](https://2023.reactjsday.it/) - [Twitter](https://twitter.com/reactjsday) - [Facebook](https://www.facebook.com/GrUSP/) - [YouTube](https://www.youtube.com/c/grusp)
 
-
 ### React Summit US 2023 {/*react-summit-us-2023*/}
 November 13 & 15, 2023. In-person in New York, US + remote first interactivity (hybrid event)
 
@@ -72,6 +71,11 @@ December 8 & 12, 2023. In-person in Berlin, Germany + remote first interactivity
 
 [Website](https://reactday.berlin) - [Twitter](https://twitter.com/reactdayberlin) - [Facebook](https://www.facebook.com/reactdayberlin/) - [Videos](https://portal.gitnation.org/events/react-day-berlin-2023)
 
+### App.js Conf 2024 {/*appjs-conf-2024*/}
+May 22 - 24, 2024. In-person in Kraków, Poland + remote
+
+[Website](https://appjs.co) - [Twitter](https://twitter.com/appjsconf)
+
 ### Render(ATL) 2024 🍑 {/*renderatl-2024-*/}
 June 12 - June 14, 2024. Atlanta, GA, USA
 

diff --git a/src/content/community/meetups.md b/src/content/community/meetups.md
@@ -48,6 +48,7 @@ Do you have a local React.js meetup? Add it here! (Please keep the list alphabet
 * [Montreal, QC - React Native](https://www.meetup.com/fr-FR/React-Native-MTL/)
 * [Vancouver, BC](https://www.meetup.com/ReactJS-Vancouver-Meetup/)
 * [Ottawa, ON](https://www.meetup.com/Ottawa-ReactJS-Meetup/)
+* [Saskatoon, SK](https://www.meetup.com/saskatoon-react-meetup/)
 * [Toronto, ON](https://www.meetup.com/Toronto-React-Native/events/)
 
 ## Chile {/*chile*/}

diff --git a/src/content/learn/describing-the-ui.md b/src/content/learn/describing-the-ui.md
@@ -18,6 +18,7 @@ React is a JavaScript library for rendering user interfaces (UI). UI is built fr
 * [How to conditionally render components](/learn/conditional-rendering)
 * [How to render multiple components at a time](/learn/rendering-lists)
 * [How to avoid confusing bugs by keeping components pure](/learn/keeping-components-pure)
+* [Why understanding your UI as trees is useful](/learn/understanding-your-ui-as-a-tree)
 
 </YouWillLearn>
 
@@ -523,6 +524,29 @@ Read **[Keeping Components Pure](/learn/keeping-components-pure)** to learn how
 
 </LearnMore>
 
+## Your UI as a tree {/*your-ui-as-a-tree*/}
+
+React uses trees to model the relationships between components and modules. 
+
+A React render tree is a representation of the parent and child relationship between components. 
+
+<Diagram name="generic_render_tree" height={250} width={500} alt="A tree graph with five nodes, with each node representing a component. The root node is located at the top the tree graph and is labelled 'Root Component'. It has two arrows extending down to two nodes labelled 'Component A' and 'Component C'. Each of the arrows is labelled with 'renders'. 'Component A' has a single 'renders' arrow to a node labelled 'Component B'. 'Component C' has a single 'renders' arrow to a node labelled 'Component D'.">An example React render tree.</Diagram>
+
+Components near the top of the tree, near the root component, are considered top-level components. Components with no child components are leaf components. This categorization of components is useful for understanding data flow and rendering performance.
+
+Modelling the relationship between JavaScript modules is another useful way to understand your app. We refer to it as a module dependency tree. 
+
+<Diagram name="generic_dependency_tree" height={250} width={500} alt="A tree graph with five nodes. Each node represents a JavaScript module. The top-most node is labelled 'RootModule.js'. It has three arrows extending to the nodes: 'ModuleA.js', 'ModuleB.js', and 'ModuleC.js'. Each arrow is labelled as 'imports'. 'ModuleC.js' node has a single 'imports' arrow that points to a node labelled 'ModuleD.js'.">An example module dependency tree.</Diagram>
+
+A dependency tree is often used by build tools to bundle all the relevant JavaScript code for the client to download and render. A large bundle size regresses user experience for React apps. Understanding the module dependency tree is helpful to debug such issues. 
+
+<LearnMore path="/learn/understanding-your-ui-as-a-tree">
+
+Read **[Your UI as a Tree](/learn/understanding-your-ui-as-a-tree)** to learn how to create a render and module dependency trees for a React app and how they're useful mental models for improving user experience and performance.
+
+</LearnMore>
+
+
 ## What's next? {/*whats-next*/}
 
 Head over to [Your First Component](/learn/your-first-component) to start reading this chapter page by page!

diff --git a/src/content/learn/preserving-and-resetting-state.md b/src/content/learn/preserving-and-resetting-state.md
@@ -10,33 +10,17 @@ State is isolated between components. React keeps track of which state belongs t
 
 <YouWillLearn>
 
-* How React "sees" component structures
 * When React chooses to preserve or reset the state
 * How to force React to reset component's state
 * How keys and types affect whether the state is preserved
 
 </YouWillLearn>
 
-## The UI tree {/*the-ui-tree*/}
+## State is tied to a position in the render tree {/*state-is-tied-to-a-position-in-the-tree*/}
 
-Browsers use many tree structures to model UI. The [DOM](https://developer.mozilla.org/docs/Web/API/Document_Object_Model/Introduction) represents HTML elements, the [CSSOM](https://developer.mozilla.org/docs/Web/API/CSS_Object_Model) does the same for CSS. There's even an [Accessibility tree](https://developer.mozilla.org/docs/Glossary/Accessibility_tree)!
-
-React also uses tree structures to manage and model the UI you make. React makes **UI trees** from your JSX. Then React DOM updates the browser DOM elements to match that UI tree. (React Native translates these trees into elements specific to mobile platforms.)
-
-<DiagramGroup>
-
-<Diagram name="preserving_state_dom_tree" height={193} width={864} alt="Diagram with three sections arranged horizontally. In the first section, there are three rectangles stacked vertically, with labels 'Component A', 'Component B', and 'Component C'. Transitioning to the next pane is an arrow with the React logo on top labeled 'React'. The middle section contains a tree of components, with the root labeled 'A' and two children labeled 'B' and 'C'. The next section is again transitioned using an arrow with the React logo on top labeled 'React'. The third and final section is a wireframe of a browser, containing a tree of 8 nodes, which has only a subset highlighted (indicating the subtree from the middle section).">
-
-From components, React creates a UI tree which React DOM uses to render the DOM
-
-</Diagram>
-
-</DiagramGroup>
-
-## State is tied to a position in the tree {/*state-is-tied-to-a-position-in-the-tree*/}
-
-When you give a component state, you might think the state "lives" inside the component. But the state is actually held inside React. React associates each piece of state it's holding with the correct component by where that component sits in the UI tree.
+React builds [render trees](learn/understanding-your-ui-as-a-tree#the-render-tree) for the component structure in your UI.
 
+When you give a component state, you might think the state "lives" inside the component. But the state is actually held inside React. React associates each piece of state it's holding with the correct component by where that component sits in the render tree.
 
 Here, there is only one `<Counter />` JSX tag, but it's rendered at two different positions:
 
@@ -190,7 +174,7 @@ Updating state
 </DiagramGroup>
 
 
-React will keep the state around for as long as you render the same component at the same position. To see this, increment both counters, then remove the second component by unchecking "Render the second counter" checkbox, and then add it back by ticking it again:
+React will keep the state around for as long as you render the same component at the same position in the tree. To see this, increment both counters, then remove the second component by unchecking "Render the second counter" checkbox, and then add it back by ticking it again:
 
 <Sandpack>
 

diff --git a/src/content/learn/referencing-values-with-refs.md b/src/content/learn/referencing-values-with-refs.md
@@ -284,7 +284,7 @@ You also don't need to worry about [avoiding mutation](/learn/updating-objects-i
 
 ## Refs and the DOM {/*refs-and-the-dom*/}
 
-You can point a ref to any value. However, the most common use case for a ref is to access a DOM element. For example, this is handy if you want to focus an input programmatically. When you pass a ref to a `ref` attribute in JSX, like `<div ref={myRef}>`, React will put the corresponding DOM element into `myRef.current`. You can read more about this in [Manipulating the DOM with Refs.](/learn/manipulating-the-dom-with-refs)
+You can point a ref to any value. However, the most common use case for a ref is to access a DOM element. For example, this is handy if you want to focus an input programmatically. When you pass a ref to a `ref` attribute in JSX, like `<div ref={myRef}>`, React will put the corresponding DOM element into `myRef.current`. Once the element is removed from the DOM, React will update `myRef.current` to be `null`. You can read more about this in [Manipulating the DOM with Refs.](/learn/manipulating-the-dom-with-refs)
 
 <Recap>
 

diff --git a/src/content/learn/rendering-lists.md b/src/content/learn/rendering-lists.md
@@ -1086,7 +1086,7 @@ Here, `<Recipe {...recipe} key={recipe.id} />` is a syntax shortcut saying "pass
 
 #### List with a separator {/*list-with-a-separator*/}
 
-This example renders a famous haiku by Katsushika Hokusai, with each line wrapped in a `<p>` tag. Your job is to insert an `<hr />` separator between each paragraph. Your resulting structure should look like this:
+This example renders a famous haiku by Tachibana Hokushi, with each line wrapped in a `<p>` tag. Your job is to insert an `<hr />` separator between each paragraph. Your resulting structure should look like this:
 
 ```js
 <article>

diff --git a/src/content/learn/start-a-new-react-project.md b/src/content/learn/start-a-new-react-project.md
@@ -21,12 +21,12 @@ If you want to build a new app or a new website fully with React, we recommend p
 **[Next.js](https://nextjs.org/) is a full-stack React framework.** It's versatile and lets you create React apps of any size--from a mostly static blog to a complex dynamic application. To create a new Next.js project, run in your terminal:
 
 <TerminalBlock>
-npx create-next-app
+npx create-next-app@latest
 </TerminalBlock>
 
 If you're new to Next.js, check out the [Next.js tutorial.](https://nextjs.org/learn/foundations/about-nextjs)
 
-Next.js is maintained by [Vercel](https://vercel.com/). You can [deploy a Next.js app](https://nextjs.org/docs/deployment) to any Node.js or serverless hosting, or to your own server. [Fully static Next.js apps](https://nextjs.org/docs/advanced-features/static-html-export) can be deployed to any static hosting.
+Next.js is maintained by [Vercel](https://vercel.com/). You can [deploy a Next.js app](https://nextjs.org/docs/app/building-your-application/deploying) to any Node.js or serverless hosting, or to your own server. Next.js also supports a [static export](https://nextjs.org/docs/pages/building-your-application/deploying/static-exports) which doesn't require a server.
 
 ### Remix {/*remix*/}
 
@@ -89,14 +89,9 @@ These features are getting closer to being production-ready every day, and we've
 
 ### Next.js (App Router) {/*nextjs-app-router*/}
 
-**[Next.js's App Router](https://beta.nextjs.org/docs/getting-started) is a redesign of the Next.js APIs aiming to fulfill the React team’s full-stack architecture vision.** It lets you fetch data in asynchronous components that run on the server or even during the build.
+**[Next.js's App Router](https://nextjs.org/docs) is a redesign of the Next.js APIs aiming to fulfill the React team’s full-stack architecture vision.** It lets you fetch data in asynchronous components that run on the server or even during the build.
 
-Next.js is maintained by [Vercel](https://vercel.com/). You can [deploy a Next.js app](https://nextjs.org/docs/deployment) to any Node.js or serverless hosting, or to your own server. Next.js also supports [static export](https://beta.nextjs.org/docs/configuring/static-export) which doesn't require a server.
-<Pitfall>
-
-Next.js's App Router is **currently in beta and is not yet recommended for production** (as of Mar 2023). To experiment with it in an existing Next.js project, [follow this incremental migration guide](https://beta.nextjs.org/docs/upgrade-guide#migrating-from-pages-to-app).
-
-</Pitfall>
+Next.js is maintained by [Vercel](https://vercel.com/). You can [deploy a Next.js app](https://nextjs.org/docs/app/building-your-application/deploying) to any Node.js or serverless hosting, or to your own server. Next.js also supports [static export](https://nextjs.org/docs/app/building-your-application/deploying/static-exports) which doesn't require a server.
 
 <DeepDive>
 

diff --git a/src/content/learn/tutorial-tic-tac-toe.md b/src/content/learn/tutorial-tic-tac-toe.md
@@ -2073,7 +2073,13 @@ export default function Game() {
 }
 ```
 
-You can see what your code should look like below. Note that you should see an error in the developer tools console that says: ``Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of `Game`.`` You'll fix this error in the next section.
+You can see what your code should look like below. Note that you should see an error in the developer tools console that says: 
+
+<ConsoleBlock level="warning">
+Warning: Each child in an array or iterator should have a unique "key" prop. Check the render method of &#96;Game&#96;.
+</ConsoleBlock>
+
+You'll fix this error in the next section.
 
 <Sandpack>
 

diff --git a/src/content/learn/typescript.md b/src/content/learn/typescript.md
@@ -284,7 +284,7 @@ export default App = AppTSX;
 
 </Sandpack>
 
-This technique works when you have an default value which makes sense - but there are occasionally cases when you do not, and in those cases `null` can feel reasonable as a default value. However, to allow the type-system to understand your code, you need to explicitly set `ContextShape | null` on the `createContext`. 
+This technique works when you have a default value which makes sense - but there are occasionally cases when you do not, and in those cases `null` can feel reasonable as a default value. However, to allow the type-system to understand your code, you need to explicitly set `ContextShape | null` on the `createContext`. 
 
 This causes the issue that you need to eliminate the `| null` in the type for context consumers. Our recommendation is to have the hook do a runtime check for it's existence and throw an error when not present:
 
@@ -460,4 +460,4 @@ We recommend the following resources:
 
  - [React TypeScript Cheatsheet](https://react-typescript-cheatsheet.netlify.app/) is a community-maintained cheatsheet for using TypeScript with React, covering a lot of useful edge cases and providing more breadth than this document.
 
- - [TypeScript Community Discord](https://discord.com/invite/typescript) is a great place to ask questions and get help with TypeScript and React issues.
+ - [TypeScript Community Discord](https://discord.com/invite/typescript) is a great place to ask questions and get help with TypeScript and React issues.
-Original file line number
+Diff line change
@@ Expand Up @@
     <Intro>
-    [React 18](https://reactjs.org/blog/2022/03/29/react-v18) was years in the making, and with it brought valuable lessons for the React team. Its release was the result of many years of research and exploring many paths. Some of those paths were successful; many more were dead-ends that led to new insights. One lesson we’ve learned is that it’s frustrating for the community to wait for new features without having insight into these paths that we’re exploring.
+    [React 18](https://react.dev/blog/2022/03/29/react-v18) was years in the making, and with it brought valuable lessons for the React team. Its release was the result of many years of research and exploring many paths. Some of those paths were successful; many more were dead-ends that led to new insights. One lesson we’ve learned is that it’s frustrating for the community to wait for new features without having insight into these paths that we’re exploring.
     </Intro>
@@ Expand Down @@