{"id":17406,"date":"2022-06-04T08:51:36","date_gmt":"2022-06-03T23:51:36","guid":{"rendered":"http:\/\/www.code-magagine.com\/?p=17406"},"modified":"2023-09-05T22:50:42","modified_gmt":"2023-09-05T13:50:42","slug":"%e3%80%90react%e3%80%91%e3%80%8c18%e3%80%8d%e3%81%ab%e3%81%a4%e3%81%84%e3%81%a6","status":"publish","type":"post","link":"http:\/\/www.code-magagine.com\/?p=17406","title":{"rendered":"\u3010React\u3011\u30d0\u30fc\u30b8\u30e7\u30f3\u300c18\u300d\u306b\u3064\u3044\u3066"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">\u958b\u767a\u6642\u306bstrict\u30e2\u30fc\u30c9\u3067\u306f2\u56de\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u304c\u884c\u308f\u308c\u308b\u3002<\/h2>\n\n\n\n<p>React18\u306estrict\u30e2\u30fc\u30c9\u306e\u4ed5\u69d8\u306b\u306a\u308a\u307e\u3059\u3002yarn start\u306a\u3069\u306e\u958b\u767a\u30e2\u30fc\u30c9\u3067\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3092\u8d77\u52d5\u3057\u305f\u5834\u5408\u3060\u3051\u9069\u7528\u3055\u308c\u307e\u3059\u3002yarn build\u3067\u30d3\u30eb\u30c9\u6642\u306b\u306f\u7279\u306b\u9069\u7528\u306f\u3055\u308c\u307e\u305b\u3093\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u3053\u306e\u6a5f\u80fd\u304c\u3042\u308b\u7406\u7531<\/h3>\n\n\n\n<p>\u958b\u767a\u6642\u306b\u4e8b\u524d\u306b\u300c\u30de\u30a6\u30f3\u30c8\u2192\u30a2\u30f3\u30de\u30a6\u30f3\u30c8\u2192\u30de\u30a6\u30f3\u30c8\u300d\u3068\u3044\u3046\u6319\u52d5\u3092\u7e70\u308a\u8fd4\u3059\u3053\u3068\u306b\u3088\u308a\u4e8b\u524d\u306b\u4e88\u671f\u3057\u306a\u3044\u526f\u4f5c\u7528\u3092\u62bd\u51fa\u3059\u308b\u3053\u3068\u3092\u76ee\u7684\u3068\u3057\u3066\u5b9f\u88c5\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u3053\u306e\u30e2\u30fc\u30c9\u3092\u89e3\u9664\u3059\u308b\u306b\u306f\uff1f<\/h3>\n\n\n\n<p>index.js\u5185\u306e\u300c&lt;React.StrictMode&gt;\u300d\u3068\u3044\u3046\u30bf\u30b0\u5185\u5bb9\u3092\u524a\u9664\u3059\u308c\u3070\u958b\u767a\u6642\u3067\u3082\u672c\u6319\u52d5\u306f\u89e3\u9664\u3055\u308c\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>root.render(\n  &lt;React.StrictMode&gt;\n\u3000&lt;\/React.StrictMode&gt;<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">Suspense\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8<\/h2>\n\n\n\n<p>\u30c7\u30fc\u30bf\u306e\u53d7\u3051\u53d6\u308a\u72b6\u614b\u3092\u691c\u77e5\u3067\u304d\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">&lt;Suspense fallback={&lt;\u5f85\u6a5f\u4e2d\u306b\u8868\u793a\u3055\u305b\u305f\u3044\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8 \/&gt;}&gt;\n  &lt;\u4efb\u610f\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8 \/&gt;\n&lt;\/Suspense&gt;<\/pre>\n\n\n\n<p>\u4efb\u610f\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\uff08\u975e\u540c\u671f\u51e6\u7406\u304c\u3042\u308b\u3082\u306e\uff09\u304c\u8fd4\u3063\u3066\u304f\u308b\u307e\u3067\u5f85\u6a5f\u4e2d\u306b\u8868\u793a\u3055\u305b\u305f\u3044\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092fallback\u3067\u6307\u5b9a\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4ed5\u7d44\u307f\u3068\u3057\u3066\u306fPromise\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306e\u72b6\u614b\u3092\u76e3\u8996\u3057\u3066pending\u306b\u306a\u3063\u3066\u3044\u308b\u5834\u5408\u306b\u6307\u5b9a\u3057\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092\u8868\u793a\u3057\u3066\u304f\u308c\u307e\u3059\u3002\uff08Promise\u304cfulfilled\u3084\u3001rejected\u306b\u306a\u3063\u305f\u3089\u7d42\u4e86\u3067\u3059\u3002\uff09<\/p>\n\n\n\n<p>\u307e\u305f\u3001Suspense\u81ea\u4f53\u306f\u30cd\u30b9\u30c8\u3082\u3067\u304d\u308b\u306e\u3067\u300c\u3042\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306f\u3053\u306e\u30c7\u30fc\u30bf\u30ed\u30fc\u30c9\u304c\u7d42\u308f\u308b\u307e\u3067\u51fa\u3059\u300d\u3001\u300c\u3055\u3089\u306b\u5225\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306f\u5225\u9014\u5f85\u3064\u300d\u306a\u3069\u306e\u8a18\u8ff0\u3082\u3067\u304d\u305f\u308a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30e1\u30ea\u30c3\u30c8<\/h3>\n\n\n\n<p>\u300c\u30ed\u30fc\u30c7\u30a3\u30f3\u30b0\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u300d\u3068\u300c\u4efb\u610f\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u300d\u306e\u30ed\u30b8\u30c3\u30af\u3092\u5206\u96e2\u3067\u304d\u308b\u306e\u3067\u826f\u3044\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Suspense on Server<\/h3>\n\n\n\n<p>\u975e\u540c\u671f\u3067\u51e6\u7406\u3092\u5f85\u3063\u3066\u3044\u308b\u9593\u306f\u90e8\u5206\u7684\u306b\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3067\u304d\u308b\u3002SSR\u304c\u91cd\u304f\u306a\u3089\u306a\u3044\u3002<\/p>\n\n\n\n<p>\u4eca\u3060\u3063\u305f\u3089ISR(\u30a2\u30af\u30bb\u30b9\u304c\u3042\u308b\u3054\u3068\u306b\u30a4\u30f3\u30bf\u30fc\u30d0\u30eb\u3092\u7f6e\u3044\u3066\u65b0\u3057\u3044\u30b5\u30a4\u30c8\u3092\u751f\u6210\u3059\u308b\u6280\u8853)\u3067\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3059\u308b\u6226\u7565\u306f\u3042\u308b\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Streaming Server Rendering with Suspense<\/h3>\n\n\n\n<p>\u6e96\u5099\u3055\u308c\u305f\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304b\u3089\u30d6\u30e9\u30a6\u30b6\u306b\u63cf\u753b\u3057\u3066\u3044\u304f\u3002\u63cf\u753b\u306e\u9045\u3044\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u3042\u308c\u3070\u4ed6\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u63cf\u753b\u3082\u305d\u308c\u306b\u5f15\u304d\u3065\u3089\u308c\u3066\u9045\u304f\u306a\u3063\u3066\u3057\u307e\u3046\u3002<\/p>\n\n\n\n<p>\u5404\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092\u4e26\u5217\u3067\u63cf\u753b\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308b\u3002<\/p>\n\n\n\n<p>\u4eca\u307e\u3067\u306f\u5168\u3066\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u63cf\u753b\u3055\u308c\u308b\u307e\u3067\u306f\u30af\u30ea\u30c3\u30af\u306a\u3069\u306e\u30a4\u30d9\u30f3\u30c8\u30cf\u30f3\u30c9\u30e9\u3082\u5b9f\u884c\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u306a\u304b\u3063\u305f\u304c\u3001\u3042\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u63cf\u753b\u304c\u5b8c\u4e86\u3059\u308b\u307e\u3067\u5f85\u305f\u306a\u304f\u3066\u3082\u5225\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u30af\u30ea\u30c3\u30af\u306a\u3069\u3092\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u3063\u305f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Nested suspense<\/h3>\n\n\n\n<p>Suspense\u306f\u5165\u308c\u5b50\u306b\u3067\u304d\u307e\u3059\u3002\u5165\u308c\u5b50\u306b\u3057\u305f\u5834\u5408\u306f\u5916\u5074\u306esuspense\u304b\u3089\u52d5\u304d\u5185\u5074\u306esuspense\u304c\u52d5\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>      &lt;Suspense fallback={&lt;Spinner \/&gt;}&gt;\n        &lt;FetchUsers \/&gt;\n        &lt;Suspense fallback={&lt;Spinner \/&gt;}&gt;\n          &lt;FetchTasks \/&gt;\n        &lt;\/Suspense&gt;\n      &lt;\/Suspense&gt;<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">React Server Component<\/h2>\n\n\n\n<p>\u30b5\u30fc\u30d0\u30fc\u5185\u3067\u3057\u304b\u5b9f\u884c\u3055\u308c\u306a\u3044\u3002<\/p>\n\n\n\n<p>SPA\u3068SSR\u3092\u5171\u5b58\u3067\u304d\u308b\u6a5f\u80fd\u3002SPA\u3067\u8868\u793a\u3055\u305b\u305f\u3044\u3082\u306e\u3092client.js\u3067\u6307\u5b9a\u3057\u3001SSR\u3067\u8868\u793a\u3055\u305b\u305f\u3044\u3082\u306e\u306fserver.js\u3068\u3044\u3046\u30d5\u30a1\u30a4\u30eb\u3092\u4f5c\u3063\u3066server.js\u5074\u3067client.js\u3092\u30a4\u30f3\u30dd\u30fc\u30c8\u3057\u3066\u4f7f\u3046\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30e1\u30ea\u30c3\u30c8<\/h3>\n\n\n\n<ul>\n<li>\u30af\u30e9\u30a4\u30a2\u30f3\u30c8\u5074\u306b\u30e9\u30a4\u30d6\u30e9\u30ea\u306a\u3069\u304c\u30d0\u30f3\u30c9\u30eb\u3055\u305b\u306a\u304f\u3066\u3082\u826f\u304f\u306a\u308b\u3002\uff08\u30d0\u30f3\u30c9\u30eb\u30b5\u30a4\u30ba\u306f\u5168\u3066\u306b\u304a\u3044\u3066\u60aa\u3060\u3057\u3067\u304d\u308b\u3060\u3051\u5c0f\u3055\u304f\u3057\u305f\u65b9\u304c\u826f\u3044\uff09<\/li>\n\n\n\n<li>\u30c7\u30fc\u30bf\u30bd\u30fc\u30b9\u306b\u30c0\u30a4\u30ec\u30af\u30c8\u306b\u30a2\u30af\u30bb\u30b9\u3067\u304d\u308b\u3002(API\u7d4c\u7531\u3067\u547c\u3073\u51fa\u3055\u306a\u304f\u3066\u3082\u3088\u304f\u306a\u308b\u3002\uff09<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">\u5236\u7d04<\/h3>\n\n\n\n<ul>\n<li>server.js\u5185\u3067\u3057\u304b\u3053\u306e\u6a5f\u80fd\u306f\u4f7f\u3048\u306a\u3044\u3002<\/li>\n\n\n\n<li>useState\u306f\u4f7f\u3048\u306a\u3044\u3002<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">\u30b9\u30c6\u30fc\u30c8\u66f4\u65b0<\/h2>\n\n\n\n<h2 class=\"wp-block-heading\">automatic batching<\/h2>\n\n\n\n<p>\u5f93\u6765\u3060\u3068\u3001state\u3092\u66f4\u65b0\u3059\u308b\u305f\u3073\u306b\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u304c\u884c\u308f\u308c\u308b\u3053\u3068\u306b\u306a\u308b\u3002\u305d\u308c\u304cstate\u304c\u4f55\u5ea6\u66f4\u65b0\u3055\u308c\u3088\u3046\u3068\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u306f1\u5ea6\u3060\u3051\u884c\u3046\u3088\u3046\u306b\u3059\u308b\u306a\u3069\u3092\u3057\u3066\u304f\u308c\u308b\u6a5f\u80fd\u3002\u6b63\u78ba\u306b\u8a00\u3048\u3070\u3001\u524d\u304b\u3089auto batching\u306e\u6a5f\u80fd\u81ea\u4f53\u306f\u3042\u3063\u305f\u306e\u3067\u3059\u304c\u300118\u304b\u3089\u306fpromise\u306a\u3069\u306b\u3082\u5bfe\u5fdc\u3055\u308c\u307e\u3057\u305f\u3002(17\u307e\u3067\u306f\u5bfe\u5fdc\u3057\u3066\u3044\u306a\u304b\u3063\u305f\u3002\uff09<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">setTimeout(() =&gt; {\n  setCount(c =&gt; c + 1);\n  setFlag(f =&gt; !f);\n  \/\/ React will only re-render once at the end (that's batching!)\n}, 1000);<\/pre>\n\n\n\n<p><span style=\"color: #ff0000;\"><strong>\u8907\u6570state\u304c\u66f4\u65b0\u3055\u308c\u308b\u5834\u5408\u306f\u3001\u6700\u5f8c\u306estate\u304c\u66f4\u65b0\u3055\u308c\u305f\u5834\u5408\u306e\u307f\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3092\u5b9f\u884c\u3059\u308b<\/strong><\/span>\u3068\u3044\u3046\u3088\u3046\u306a\u4ed5\u69d8\u306b\u5909\u66f4\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30e6\u30fc\u30b9\u30b1\u30fc\u30b9<\/h3>\n\n\n\n<p>axios\u306a\u3069\u3067API\u3092\u5b9f\u884c\u3057\u3066\u53d6\u5f97\u3057\u305f\u51e6\u7406\u7d50\u679c\u306a\u3069\u3067state\u3092\u8907\u6570\u66f4\u65b0\u3059\u308b\u5834\u5408\u3067\u3082\u4e00\u5ea6\u3057\u304b\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u304c\u767a\u751f\u3057\u306a\u304f\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u3053\u306e\u6319\u52d5\u3092\u7121\u52b9\u5316\u3057\u305f\u3044\u5834\u5408\uff08React17\u3068\u540c\u3058\u6319\u52d5\u306b\u3057\u305f\u3044\u5834\u5408\uff09<\/h3>\n\n\n\n<p>flushSync\u3092\u4f7f\u3044\u307e\u3059\u3002\u4ee5\u4e0b\u306e\u3088\u3046\u306bsetState\u5185\u3092\u305d\u308c\u305e\u308cflushSync\u306e\u69cb\u6587\u3067\u56f2\u3044\u307e\u3059\u3002React17\u3068\u540c\u3058\u3088\u3046\u306b\u305d\u308c\u305e\u308c\u3067\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>import { flushSync } from 'react-dom'\n\n    axios.get('URL').then((res) =&gt; {\n      flushSync(() =&gt; {\n         setA(res.a)\n      })\n      flushSync(() =&gt; {\n         setB(res.b)\n      })\n<\/code><\/pre>\n\n\n\n<h2 class=\"wp-block-heading\">\u30b3\u30f3\u30ab\u30ec\u30f3\u30c8\u30e2\u30fc\u30c9\u3092\u5b9f\u73fe\u3059\u308b\u305f\u3081\u306e\u65b0API\u304c\u8ffd\u52a0\u3055\u308c\u308b\u3002<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">useTransition\u3001startTransition<\/h3>\n\n\n\n<p>\u57fa\u672c\u306f\u4f7f\u308f\u306a\u3044\u3053\u3068\u3002\u4ed6\u306e\u4ee3\u66ff\u624b\u6cd5\u3067\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u6700\u9069\u5316\u3067\u304d\u308b\u304b\u8a66\u3057\u3066\u305d\u308c\u3067\u3082\u3060\u3081\u306a\u3089\u4f7f\u3046\u3053\u3068\u3092\u691c\u8a0e\u3059\u308b\u3002<\/p>\n\n\n\n<p>React17\u307e\u3067\u306fstate\u306e\u66f4\u65b0\u306b\u512a\u5148\u9806\u4f4d\u3092\u3064\u3051\u308b\u3053\u3068\u306f\u3067\u304d\u306a\u304b\u3063\u305f\u3002\u512a\u5148\u5ea6\u304c\u9ad8\u3044\u51e6\u7406\u3092\u4f4e\u3044\u51e6\u7406\u306b\u5272\u308a\u8fbc\u307e\u305b\u3066\u5b9f\u884c\u3055\u305b\u308b\u3068\u3044\u3046\u30b3\u30f3\u30ab\u30ec\u30f3\u30c8\uff08\u4e26\u5217\u8a08\u7b97\uff09\u306a\u5b9f\u884c\u304cReact18\u3067\u53ef\u80fd\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<p>startTransition\u3067\u6307\u5b9a\u3059\u308bstate\u306f\u7dca\u6025\u6027\u304c\u306a\u3044state\u3068\u307f\u306a\u3059\u3053\u3068\u304c\u3067\u304d\u7279\u5b9a\u51e6\u7406\u306e\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u3092\u4e0a\u3052\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u3002<\/p>\n\n\n\n<p>\u4f8b\u3048\u3070\u3001\u300c\u30d5\u30a9\u30fc\u30e0\u753b\u9762\u3067\u30c6\u30ad\u30b9\u30c8\u30dc\u30c3\u30af\u30b9\u3078\u306e\u5165\u529b\u304a\u3088\u3073\u53cd\u6620\u306f\u7dca\u6025\u6027\u304c\u9ad8\u3044\u306e\u3067\u512a\u5148\u5ea6\u3092\u4e0a\u3052\u305f\u3044\u300d\u307f\u305f\u3044\u306a\u5834\u5408\u306b\u4f7f\u3048\u307e\u3059\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u4f8b<\/h4>\n\n\n\n<p>\u30d5\u30a9\u30fc\u30e0\u306b\u5165\u529b\u3057\u305f\u5024\u3092\u5143\u306b\u30d5\u30a3\u30eb\u30bf\u30fc\u3059\u308b\u51e6\u7406\u304c\u3042\u308b\u3068\u3057\u305f\u3089\u3001\u30ad\u30fc\u5165\u529b\u306e\u72b6\u614b\u66f4\u65b0\u306e\u512a\u5148\u5ea6\u3092\u4e0a\u3052\u3066\u3001\u30d5\u30a3\u30eb\u30bf\u30fc\u306f\u5c11\u3057\u512a\u5148\u5ea6\u3092\u4e0b\u3052\u308b\u306a\u3069\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">\u5b9f\u88c5\u4f8b<\/h4>\n\n\n\n<pre class=\"wp-block-preformatted\">const [isPending, startTransition] = useTransition()\n<\/pre>\n\n\n\n<h5 class=\"wp-block-heading\">isPending<\/h5>\n\n\n\n<p>true\u306a\u3089\u512a\u5148\u5ea6\u304c\u9ad8\u3044state\u304c\u66f4\u65b0\u3055\u308c\u3066\u3044\u3066\u3001\u512a\u5148\u5ea6\u304c\u4f4e\u3044state\u304c\u307e\u3060\u66f4\u65b0\u3055\u308c\u3066\u306a\u3044\u3053\u3068\u3092\u6307\u3057\u307e\u3059\u3002false\u306a\u3089\u5168\u3066\u306estate\u304c\u66f4\u65b0\u3055\u308c\u3066\u3044\u308b\u72b6\u614b\u3092\u6307\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u4f8b\u3048\u3070\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306binput\u3068updateValue\u3068\u3044\u3046\u72b6\u614b\u304c\u3042\u3063\u305f\u3068\u3057\u305f\u3089startTrasition\u3092\u6307\u5b9a\u3057\u3066\u3044\u308b\u72b6\u614b(updateValue\uff09\u306f\u66f4\u65b0\u3092\u9045\u5ef6\u3055\u305b\u308b\u3053\u3068\u304c\u53ef\u80fd\u3067\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">  const update = (e) =&gt; {\n    setInput(e.target.value)\n    startTransition(() =&gt; setUpdateValue(e.target.value))\n  }<\/pre>\n\n\n\n<p>\u3082\u3057\u305d\u3053\u307e\u3067\u30d1\u30d5\u30a9\u30fc\u30de\u30f3\u30b9\u304c\u60aa\u304f\u306a\u3044\u30da\u30fc\u30b8\u306e\u5834\u5408\u306b\u52b9\u679c\u3092\u4f53\u611f\u3057\u305f\u3044\u5834\u5408\u306fChrome\u306e\u958b\u767a\u8005\u30c4\u30fc\u30eb\u306ePerformance\u30bf\u30d6\u306e\u4e2d\u306eCPU\u306e\u5024\u3092\u300c4x slowdown\u300d\u306a\u3069\u306b\u5909\u66f4\u3059\u308b\u3053\u3068\u3067\u691c\u8a3c\u3059\u308b\u3053\u3068\u304c\u53ef\u80fd\u3067\u3059\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" loading=\"lazy\" width=\"277\" height=\"111\" src=\"http:\/\/www.code-magagine.com\/wp-content\/uploads\/2023\/09\/image-4.png\" alt=\"\" class=\"wp-image-22400\"\/><\/figure>\n\n\n\n<p>startTransition\u3092\u4ed8\u3051\u3066\u3044\u306a\u3044state\u306e\u66f4\u65b0\u306f\u4eee\u306b\u4e0a\u8a18\u306e\u3088\u3046\u306b\u30b9\u30ed\u30fc\u30c0\u30a6\u30f3\u3057\u3066\u3044\u305f\u3068\u3057\u3066\u3082\u901f\u653b\u3067\u63cf\u753b\u304c\u7d42\u308f\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">useDeferredValue<\/h3>\n\n\n\n<p>\u57fa\u672c\u7684\u306b\u306fuseTransition\u3068\u540c\u3058\u3088\u3046\u306b\u4f7f\u3046\u306e\u3067useTransition\u3092\u512a\u5148\u3057\u3066\u4f7f\u3048\u3070\u3088\u3044\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u305f\u3060\u3001\u4e00\u70b9\u3060\u3051\u7528\u9014\u304c\u7570\u306a\u308b\u3002<\/p>\n\n\n\n<p>useTransition\u3060\u3068\u66f4\u65b0\u7528\u95a2\u6570\u3092startTransition\u3067\u56f2\u3046\u3053\u3068\u306b\u306a\u308b\u3002\u3057\u304b\u3057\u30e9\u30a4\u30d6\u30e9\u30ea\u306a\u3069\u3092\u5229\u7528\u3057\u3066\u3044\u308b\u5834\u5408\u306a\u3069\u3067\u4f7f\u3048\u306a\u3044\u30b1\u30fc\u30b9\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>const \u9045\u5ef6\u3055\u305b\u305f\u3044\u5024 = \u95a2\u6570();\r\r\nconst \u9045\u5ef6\u5f8c\u306e\u5024 = useDeferredValue(\u9045\u5ef6\u3055\u305b\u305f\u3044\u5024)<\/code><\/pre>\n\n\n\n<p>useTransition\u306f\u9045\u5ef6\u3055\u305b\u305f\u3044\u95a2\u6570\u3092\u30e9\u30c3\u30d7\u3057\u3066\u3044\u305f\u304c\u3001useDeferredValue\u306f\u9045\u5ef6\u3055\u305b\u305f\u3044\u5024\u3092\u30e9\u30c3\u30d7\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u3061\u306a\u307f\u306b\u4e0a\u8a18\u4f8b\u3067\u3044\u3048\u3070\u3001\u300c\u9045\u5ef6\u3055\u305b\u305f\u3044\u5024\u300d\u3068\u300c\u9045\u5ef6\u5f8c\u306e\u5024\u300d\u306f\u4e2d\u8eab\u306f\u540c\u3058\u306a\u306e\u3067\u3059\u304c\u3001\u66f4\u65b0\u306e\u512a\u5148\u5ea6\u304c\u4ed6\u306e\u5024\u306b\u6bd4\u3079\u3066\u4e0b\u304c\u308a\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u958b\u767a\u6642\u306bstrict\u30e2\u30fc\u30c9\u3067\u306f2\u56de\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u304c\u884c\u308f\u308c\u308b\u3002 React18\u306estrict\u30e2\u30fc\u30c9\u306e\u4ed5\u69d8\u306b\u306a\u308a\u307e\u3059\u3002yarn start\u306a\u3069\u306e\u958b\u767a\u30e2\u30fc\u30c9\u3067\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3092\u8d77\u52d5\u3057\u305f\u5834\u5408\u3060\u3051\u9069\u7528\u3055\u308c\u307e\u3059\u3002yarn build\u3067 [&hellip;]","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[116],"tags":[],"_links":{"self":[{"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=\/wp\/v2\/posts\/17406"}],"collection":[{"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=17406"}],"version-history":[{"count":23,"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=\/wp\/v2\/posts\/17406\/revisions"}],"predecessor-version":[{"id":22434,"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=\/wp\/v2\/posts\/17406\/revisions\/22434"}],"wp:attachment":[{"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=17406"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=17406"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.code-magagine.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=17406"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}