From 6671ba7b77142a73184caf863890d5ff20f2361b Mon Sep 17 00:00:00 2001 From: Oliver Joseph Ash Date: Wed, 7 Aug 2024 10:46:23 +0100 Subject: [PATCH 1/5] Document behaviour of setting state inside `useLayoutEffect` (#7096) Co-authored-by: Sebastian Silbermann --- src/content/reference/react/useLayoutEffect.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/content/reference/react/useLayoutEffect.md b/src/content/reference/react/useLayoutEffect.md index 0d7b04841..d38458f14 100644 --- a/src/content/reference/react/useLayoutEffect.md +++ b/src/content/reference/react/useLayoutEffect.md @@ -67,6 +67,8 @@ function Tooltip() { * The code inside `useLayoutEffect` and all state updates scheduled from it **block the browser from repainting the screen.** When used excessively, this makes your app slow. When possible, prefer [`useEffect`.](/reference/react/useEffect) +* If you trigger a state update inside `useLayoutEffect`, React will execute all remaining Effects immediately including `useEffect`. + --- ## Usage {/*usage*/} From 2bfa7a628b0534bb0d437ff7520a72010ab970c3 Mon Sep 17 00:00:00 2001 From: lauren Date: Thu, 8 Aug 2024 10:43:41 -0400 Subject: [PATCH 2/5] Update compiler docs installation instructions (#7095) --- src/content/learn/react-compiler.md | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/content/learn/react-compiler.md b/src/content/learn/react-compiler.md index f34c382ed..2920e8643 100644 --- a/src/content/learn/react-compiler.md +++ b/src/content/learn/react-compiler.md @@ -121,7 +121,7 @@ In addition to these docs, we recommend checking the [React Compiler Working Gro Prior to installing the compiler, you can first check to see if your codebase is compatible: -npx react-compiler-healthcheck@latest +npx react-compiler-healthcheck@experimental This script will: @@ -143,7 +143,7 @@ Found no usage of incompatible libraries. React Compiler also powers an eslint plugin. The eslint plugin can be used **independently** of the compiler, meaning you can use the eslint plugin even if you don't use the compiler. -npm install eslint-plugin-react-compiler +npm install eslint-plugin-react-compiler@experimental Then, add it to your eslint config: @@ -203,7 +203,7 @@ If you're starting a new project, you can enable the compiler on your entire cod ### Babel {/*usage-with-babel*/} -npm install babel-plugin-react-compiler +npm install babel-plugin-react-compiler@experimental The compiler includes a Babel plugin which you can use in your build pipeline to run the compiler. @@ -258,7 +258,7 @@ Next.js has an experimental configuration to enable the React Compiler. It autom - Install `babel-plugin-react-compiler` -npm install next@canary babel-plugin-react-compiler +npm install next@canary babel-plugin-react-compiler@experimental Then configure the experimental option in `next.config.js`: From a220bb3f21170210fb37375f349c943150a5364d Mon Sep 17 00:00:00 2001 From: k8o <61353435+k35o@users.noreply.github.com> Date: Thu, 22 Aug 2024 16:46:36 +0900 Subject: [PATCH 3/5] docs: replace check mark emoji to check mark button emoji (#7121) --- .../blog/2023/03/16/introducing-react-dev.md | 4 +-- src/content/learn/conditional-rendering.md | 32 +++++++++---------- src/content/learn/describing-the-ui.md | 2 +- 3 files changed, 19 insertions(+), 19 deletions(-) diff --git a/src/content/blog/2023/03/16/introducing-react-dev.md b/src/content/blog/2023/03/16/introducing-react-dev.md index 2498f40dc..c4da2b61f 100644 --- a/src/content/blog/2023/03/16/introducing-react-dev.md +++ b/src/content/blog/2023/03/16/introducing-react-dev.md @@ -269,7 +269,7 @@ Use the conditional operator (`cond ? a : b`) to render a ❌ if `isPacked` isn function Item({ name, isPacked }) { return (
  • - {name} {isPacked && '✔'} + {name} {isPacked && '✅'}
    • ); } @@ -307,7 +307,7 @@ export default function PackingList() { function Item({ name, isPacked }) { return (
  • - {name} {isPacked ? '✔' : '❌'} + {name} {isPacked ? '✅' : '❌'}
    • ); } diff --git a/src/content/learn/conditional-rendering.md b/src/content/learn/conditional-rendering.md index 895d610d3..95be5d2e0 100644 --- a/src/content/learn/conditional-rendering.md +++ b/src/content/learn/conditional-rendering.md @@ -52,13 +52,13 @@ export default function PackingList() { -Notice that some of the `Item` components have their `isPacked` prop set to `true` instead of `false`. You want to add a checkmark (✔) to packed items if `isPacked={true}`. +Notice that some of the `Item` components have their `isPacked` prop set to `true` instead of `false`. You want to add a checkmark (✅) to packed items if `isPacked={true}`. You can write this as an [`if`/`else` statement](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if...else) like so: ```js if (isPacked) { - return
  • {name} ✔
    • ; + return
  • {name} ✅
    • ; } return
  • {name}
    • ; ``` @@ -70,7 +70,7 @@ If the `isPacked` prop is `true`, this code **returns a different JSX tree.** Wi ```js function Item({ name, isPacked }) { if (isPacked) { - return
  • {name} ✔
    • ; + return
  • {name} ✅
    • ; } return
  • {name}
    • ; } @@ -159,7 +159,7 @@ In practice, returning `null` from a component isn't common because it might sur In the previous example, you controlled which (if any!) JSX tree would be returned by the component. You may already have noticed some duplication in the render output: ```js -
  • {name} ✔
    • +
  • {name} ✅
    • ``` is very similar to @@ -172,7 +172,7 @@ Both of the conditional branches return `
  • ...
    • `: ```js if (isPacked) { - return
  • {name} ✔
    • ; + return
  • {name} ✅
    • ; } return
  • {name}
    • ; ``` @@ -187,7 +187,7 @@ Instead of this: ```js if (isPacked) { - return
  • {name} ✔
    • ; + return
  • {name} ✅
    • ; } return
  • {name}
    • ; ``` @@ -197,12 +197,12 @@ You can write this: ```js return (
  • - {isPacked ? name + ' ✔' : name} + {isPacked ? name + ' ✅' : name}
    • ); ``` -You can read it as *"if `isPacked` is true, then (`?`) render `name + ' ✔'`, otherwise (`:`) render `name`"*. +You can read it as *"if `isPacked` is true, then (`?`) render `name + ' ✅'`, otherwise (`:`) render `name`"*. @@ -222,7 +222,7 @@ function Item({ name, isPacked }) {
  • {isPacked ? ( - {name + ' ✔'} + {name + ' ✅'} ) : ( name @@ -265,7 +265,7 @@ Another common shortcut you'll encounter is the [JavaScript logical AND (`&&`) o ```js return (
  • - {name} {isPacked && '✔'} + {name} {isPacked && '✅'}
    • ); ``` @@ -280,7 +280,7 @@ Here it is in action: function Item({ name, isPacked }) { return (
  • - {name} {isPacked && '✔'} + {name} {isPacked && '✅'}
    • ); } @@ -337,7 +337,7 @@ Use an `if` statement to reassign a JSX expression to `itemContent` if `isPacked ```js if (isPacked) { - itemContent = name + " ✔"; + itemContent = name + " ✅"; } ``` @@ -357,7 +357,7 @@ This style is the most verbose, but it's also the most flexible. Here it is in a function Item({ name, isPacked }) { let itemContent = name; if (isPacked) { - itemContent = name + " ✔"; + itemContent = name + " ✅"; } return (
  • @@ -401,7 +401,7 @@ function Item({ name, isPacked }) { if (isPacked) { itemContent = ( - {name + " ✔"} + {name + " ✅"} ); } @@ -464,7 +464,7 @@ Use the conditional operator (`cond ? a : b`) to render a ❌ if `isPacked` isn function Item({ name, isPacked }) { return (
  • - {name} {isPacked && '✔'} + {name} {isPacked && '✅'}
    • ); } @@ -502,7 +502,7 @@ export default function PackingList() { function Item({ name, isPacked }) { return (
  • - {name} {isPacked ? '✔' : '❌'} + {name} {isPacked ? '✅' : '❌'}
    • ); } diff --git a/src/content/learn/describing-the-ui.md b/src/content/learn/describing-the-ui.md index ce49b85c8..34ee0c01a 100644 --- a/src/content/learn/describing-the-ui.md +++ b/src/content/learn/describing-the-ui.md @@ -327,7 +327,7 @@ In this example, the JavaScript `&&` operator is used to conditionally render a function Item({ name, isPacked }) { return (
  • - {name} {isPacked && '✔'} + {name} {isPacked && '✅'}
    • ); } From b5f28b48441e7e46c11ba066110a3c952c33c4ba Mon Sep 17 00:00:00 2001 From: Bartosz Klonowski <70535775+BartoszKlonowski@users.noreply.github.com> Date: Fri, 23 Aug 2024 14:21:11 +0200 Subject: [PATCH 4/5] Redirect lists-and-keys to rendering-lists describing key (#7120) --- vercel.json | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/vercel.json b/vercel.json index eac0efb9c..8b0546e37 100644 --- a/vercel.json +++ b/vercel.json @@ -24,6 +24,11 @@ "destination": "/learn/rendering-lists#keeping-list-items-in-order-with-key", "permanent": false }, + { + "source": "/docs/lists-and-keys", + "destination": "/learn/rendering-lists#keeping-list-items-in-order-with-key", + "permanent": false + }, { "source": "/link/invalid-hook-call", "destination": "/warnings/invalid-hook-call-warning", From 7d50c3ffd4df2dc7903f4e41069653a456a9c223 Mon Sep 17 00:00:00 2001 From: Bartosz Klonowski <70535775+BartoszKlonowski@users.noreply.github.com> Date: Sun, 25 Aug 2024 22:32:42 +0200 Subject: [PATCH 5/5] Emphasize the second problem paragraph with chain of effects example (#7108) * Emphasize the second problem acapit with chain of effects example * Replace 'One' with 'First' to keep problems counting consistent --- src/content/learn/you-might-not-need-an-effect.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/content/learn/you-might-not-need-an-effect.md b/src/content/learn/you-might-not-need-an-effect.md index 66cdc3117..27031720d 100644 --- a/src/content/learn/you-might-not-need-an-effect.md +++ b/src/content/learn/you-might-not-need-an-effect.md @@ -408,9 +408,9 @@ function Game() { There are two problems with this code. -One problem is that it is very inefficient: the component (and its children) have to re-render between each `set` call in the chain. In the example above, in the worst case (`setCard` → render → `setGoldCardCount` → render → `setRound` → render → `setIsGameOver` → render) there are three unnecessary re-renders of the tree below. +First problem is that it is very inefficient: the component (and its children) have to re-render between each `set` call in the chain. In the example above, in the worst case (`setCard` → render → `setGoldCardCount` → render → `setRound` → render → `setIsGameOver` → render) there are three unnecessary re-renders of the tree below. -Even if it weren't slow, as your code evolves, you will run into cases where the "chain" you wrote doesn't fit the new requirements. Imagine you are adding a way to step through the history of the game moves. You'd do it by updating each state variable to a value from the past. However, setting the `card` state to a value from the past would trigger the Effect chain again and change the data you're showing. Such code is often rigid and fragile. +The second problem is that even if it weren't slow, as your code evolves, you will run into cases where the "chain" you wrote doesn't fit the new requirements. Imagine you are adding a way to step through the history of the game moves. You'd do it by updating each state variable to a value from the past. However, setting the `card` state to a value from the past would trigger the Effect chain again and change the data you're showing. Such code is often rigid and fragile. In this case, it's better to calculate what you can during rendering, and adjust the state in the event handler: