{"id":2565,"date":"2022-04-22T12:41:34","date_gmt":"2022-04-22T03:41:34","guid":{"rendered":"https:\/\/weseek.co.jp\/tech\/?p=2565"},"modified":"2023-04-17T10:27:37","modified_gmt":"2023-04-17T01:27:37","slug":"react%e3%81%ab%e3%81%8a%e3%81%91%e3%82%8bglobal-state%e3%81%ae%e7%ae%a1%e7%90%86%e6%b3%954%e9%81%b8","status":"publish","type":"post","link":"https:\/\/weseek.co.jp\/tech\/2565\/","title":{"rendered":"React\u306b\u304a\u3051\u308bGlobal state\u306e\u7ba1\u7406\u6cd54\u9078"},"content":{"rendered":"

\u3053\u306e\u6295\u7a3f\u306f\u3001\u5f0a\u793e\u304c\u63d0\u4f9b\u3059\u308bWESEEK TECH\u901a\u4fe1<\/b>\u306e\u4e00\u74b0\u3067\u3059\u3002
\nWESEEK TECH\u901a\u4fe1\u3068\u306f\u3001WESEEK\u306e\u30a8\u30f3\u30b8\u30cb\u30a2\u304c\u30ad\u30e3\u30c3\u30c1\u30a2\u30c3\u30d7\u3057\u305f\u6280\u8853\u306b\u95a2\u3059\u308b\u60c5\u5831\u3092\u3001tech\u30d6\u30ed\u30b0\u3092\u901a\u3058\u3066\u5b9a\u671f\u7684\u306b\u767a\u4fe1\u3057\u3066\u3044\u304f\u3082\u306e\u3067\u3059\u3002<\/p>\n

\u306f\u3058\u3081\u306b<\/h2>\n

\u4eca\u56de\u306e\u8a18\u4e8b\u3067\u306f React \u306b\u304a\u3051\u308b Global state \u306e\u7ba1\u7406\u6cd5\u306b\u3064\u3044\u3066\u3055\u307e\u3056\u307e\u306a\u65b9\u6cd5\u3092\u3001\u305d\u308c\u305e\u308c\u306e\u30e1\u30ea\u30c3\u30c8\u30c7\u30e1\u30ea\u30c3\u30c8\u3068\u3068\u3082\u306b\u89e3\u8aac\u3057\u307e\u3059\u3002<\/p>\n

React \u3067\u5927\u898f\u6a21\u306a\u958b\u767a\u3092\u884c\u3046\u969b\u306b Global state \u306e\u7ba1\u7406\u6cd5\u304c\u5b9a\u307e\u3063\u3066\u3044\u308b\u3068\u975e\u5e38\u306b\u958b\u767a\u304c\u697d\u306b\u306a\u308b\u305f\u3081\u3001\u662f\u975e\u3068\u3082\u3053\u306e\u3044\u305a\u308c\u304b\u306e\u65b9\u6cd5\u3092\u7406\u89e3\u3057\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n

<\/p>\n\n

Global state\u306e\u7ba1\u7406\u304c\u5fc5\u8981\u306a\u7406\u7531<\/h2>\n

React \u306b\u304a\u3044\u3066\u3001\u4f8b\u3048\u3070\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u69cb\u6210\u304c5\u968e\u5c64\u306b\u306a\u3063\u3066\u3044\u305f\u5834\u5408\u306b\u3001\u4e00\u756a\u4e0a\u306e\u968e\u5c64\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067\u5b9a\u7fa9\u3057\u3066\u3044\u308b state \u3092\u4e00\u756a\u4e0b\u306e\u968e\u5c64\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u6e21\u3057\u305f\u3044\u5834\u5408\u306f\u3069\u3046\u3059\u308c\u3070\u826f\u3044\u3067\u3057\u3087\u3046\u304b\u3002
\n\u4e0a\u304b\u3089\u4e0b\u307e\u3067\u306e\u305d\u308c\u305e\u308c\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067 state \u3092 props \u3068\u3057\u3066\u6e21\u3057\u3066\u3042\u3052\u308b\u3053\u3068\u3067\u3001\u4e00\u756a\u4e0b\u306e\u968e\u5c64\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u307e\u3067\u6e21\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n

\u3057\u304b\u3057\u3001\u3053\u306e\u65b9\u6cd5\u3067\u306f state \u3092\u30d0\u30b1\u30c4\u30ea\u30ec\u30fc\u306e\u3088\u3046\u306b\u8907\u6570\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u307e\u305f\u304c\u3063\u3066\u6e21\u3057\u3066\u3044\u308b\u305f\u3081\u3001\u30b3\u30fc\u30c9\u304c\u8907\u96d1\u5316\u3057\u3066\u3057\u307e\u3044\u307e\u3059\u3002\u307e\u305f\u3001\u4e2d\u9593\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u3068\u3063\u3066\u306f\u672c\u6765\u5fc5\u8981\u306e\u306a\u3044 props \u3092\u53d7\u3051\u53d6\u3063\u3066\u3044\u308b\u305f\u3081\u3001\u518d\u5229\u7528\u306e\u96e3\u3057\u3044\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u306a\u3063\u3066\u3057\u307e\u3046\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u305d\u306e\u4ed6\u306b\u3082\u3001\u4e2d\u9593\u306b\u4f4d\u7f6e\u3059\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u9054\u306f state \u304c\u66f4\u65b0\u3055\u308c\u308b\u305f\u3073\u306b\u3001\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u306e\u5fc5\u8981\u304c\u306a\u3044\u306b\u3082\u304b\u304b\u308f\u3089\u305a\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u3066\u3057\u307e\u3046\u3068\u3044\u3046\u554f\u984c\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n

\u3053\u308c\u3089\u306e\u554f\u984c\u3092\u89e3\u6c7a\u3057\u3001\u7121\u99c4\u306a\u30b3\u30fc\u30c9\u3084\u7121\u99c4\u306a\u6319\u52d5\u3092\u6e1b\u3089\u3059\u305f\u3081\u306b Global state \u304c\u5fc5\u8981\u306b\u306a\u308b\u3068\u3044\u3046\u3053\u3068\u3067\u3059\u3002<\/p>\n

1. React Context<\/h2>\n

\u4e00\u756a\u521d\u3081\u306b\u7d39\u4ecb\u3059\u308b\u306e\u306f\u3001React \u306e\u6a19\u6e96\u6a5f\u80fd\u3068\u3057\u3066\u5099\u308f\u3063\u3066\u3044\u308b useContext<\/a> \u3092\u4f7f\u7528\u3057\u305f\u65b9\u6cd5\u3067\u3059\u3002
\n\u3053\u306e\u65b9\u6cd5\u306f React \u3055\u3048\u5c0e\u5165\u3055\u308c\u3066\u3044\u308c\u3070\u4f7f\u7528\u3067\u304d\u308b\u305f\u3081\u3001\u8ffd\u52a0\u3067\u4ed6\u306e\u30d1\u30c3\u30b1\u30fc\u30b8\u3092\u30a4\u30f3\u30b9\u30c8\u30fc\u30eb\u3059\u308b\u5fc5\u8981\u304c\u306a\u3044\u3053\u3068\u304c\u30e1\u30ea\u30c3\u30c8\u3067\u3059\u3002<\/p>\n

\u307e\u305a\u521d\u3081\u306b\u3001\u30da\u30fc\u30b8\u5168\u4f53\u306e\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u3092 Global state \u3068\u3057\u3066\u6271\u3046\u3053\u3068\u3092\u60f3\u5b9a\u3057\u3066\u3001\u4e00\u756a\u4e0a\u306e Top \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067\u5b9a\u7fa9\u3055\u308c\u305f\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u3092\u4e00\u756a\u4e0b\u306e Bottom \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u8868\u793a\u3055\u305b\u308b\u3068\u3044\u3046\u4f8b\u3092\u7528\u610f\u3057\u307e\u3059\u3002<\/p>\n

import { useState } from 'react'\n\nconst Top = () => {\n  const [themeColor] = useState('dark')\n\n  return (\n    <Middle color={themeColor} \/>\n  )\n}\n\nconst Middle = (props) => {\n  return (\n    <Bottom color={props.color} \/>\n  )\n}\n\nconst Bottom = (props) => {\n  return (\n    <div>\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u306f {props.color} \u3067\u3059\u3002<\/div>\n  )\n}<\/code><\/pre>\n
\u4e2d\u9593\u306e Middle \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067\u306f\u3001\u6b21\u306e Bottom \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b props \u3092\u6e21\u3059\u305f\u3081\u3060\u3051\u306b props \u3092\u53d7\u3051\u53d6\u3063\u3066\u3044\u308b\u3053\u3068\u304c\u5206\u304b\u308a\u307e\u3059\u3002
\n(\u3053\u306e\u7a0b\u5ea6\u3067\u3042\u308c\u3070\u5168\u7136\u554f\u984c\u306f\u306a\u3044\u3067\u3059\u304c) \u3082\u3057 state \u306e\u6e21\u3057\u5148\u304c\u305a\u3063\u3068\u4e0b\u5c64\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067\u3042\u3063\u305f\u5834\u5408\u306f\u8907\u96d1\u306a\u30b3\u30fc\u30c9\u3068\u306a\u3063\u3066\u3057\u307e\u3044\u307e\u3059\u3002
\n\u3053\u306e\u4f8b\u3092\u5143\u306b useContext \u3092\u4f7f\u7528\u3057\u3066\u3001Top \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304b\u3089 Bottom \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u76f4\u63a5 state \u3092\u6e21\u305b\u308b\u3088\u3046\u306b\u6539\u5584\u3057\u307e\u3059\u3002<\/p>\n
React \u306e context \u6a5f\u80fd\u3092\u4f7f\u7528\u3057\u305f Global state \u7ba1\u7406\u306e\u624b\u9806\u306f\u975e\u5e38\u306b\u30b7\u30f3\u30d7\u30eb\u3067\u3001\u4ee5\u4e0b\u306e4\u30b9\u30c6\u30c3\u30d7\u3067\u5b9f\u65bd\u3067\u304d\u307e\u3059\u3002<\/p>\n
    \n
  1. React.createContext \u3067 Context \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4f5c\u6210\u3059\u308b<\/li>\n
  2. Context.Provider \u306e value \u306b\u5bfe\u3057\u3066 state \u3092\u6e21\u3059<\/li>\n
  3. state \u306e\u6e21\u3057\u5148\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092 Context.Provider \u3067\u56f2\u3046<\/li>\n
  4. \u6e21\u3057\u5148\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067 React.useContext \u3092\u4f7f\u7528\u3057\u3066 state \u3092\u547c\u3073\u51fa\u3059<\/li>\n<\/ol>\n
    \u4f8b\u3092\u898b\u3066\u3044\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n
    import { useState, createContext, useContext } from 'react'\n\nconst SampleContext = createContext('light')\n\nconst Top = () => {\n  const [themeColor] = useState('dark')\n\n  return (\n    <SampleContext.Provider value={themeColor}>\n      <Middle \/>\n    <\/SampleContext.Provider>\n  )\n}\n\nconst Middle = () => {\n  return (\n    <Bottom \/>\n  )\n}\n\nconst Bottom = () => {\n  const color = useContext(SampleContext)\n\n  return (\n    <div>\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u306f {color} \u3067\u3059\u3002<\/div>\n  )\n}<\/code><\/pre>\n
    \u307e\u305a\u3001createContext \u3067 Context \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092\u4f5c\u6210\u3057\u307e\u3059\u3002
    \ncreateContext \u306e\u5f15\u6570\u306b\u306f Global state \u306e\u521d\u671f\u5024\u3092\u8a2d\u5b9a\u3067\u304d\u307e\u3059\u3002\u4eca\u56de\u306f light \u3068\u3057\u307e\u3059\u3002<\/p>\n
    const SampleContext = createContext('light')<\/code><\/pre>\n
    \u6b21\u306b\u3001Context.Provider \u306e value \u306b\u3001Global state \u3068\u3057\u3066\u7ba1\u7406\u3059\u308b state \u3092\u6e21\u3057\u307e\u3059\u3002<\/p>\n
    \u305d\u3057\u3066\u3001Context.Provider \u3067 Middle \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092\u56f2\u3044\u307e\u3059\u3002
    \n\u3053\u3046\u3059\u308b\u3053\u3068\u306b\u3088\u308a\u3001Middle \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3068\u305d\u306e\u914d\u4e0b\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067\u3001useContext \u306e\u4f7f\u7528\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
    const Top = () => {\n  const [themeColor] = useState('dark')\n\n  return (\n    <SampleContext.Provider value={themeColor}>\n      <Middle \/>\n    <\/SampleContext.Provider>\n  )\n}<\/code><\/pre>\n
    \u6700\u5f8c\u306b\u3001createContext \u3067\u4f5c\u6210\u3057\u305f Context \u3092 useContext \u306e\u5f15\u6570\u306b\u6e21\u3057\u3066\u3042\u3052\u308b\u3053\u3068\u3067 Global state \u3092\u547c\u3073\u51fa\u3059\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
    const Middle = () => {\n  return (\n    <Bottom \/>\n  )\n}\n\nconst Bottom = () => {\n  const color = useContext(SampleContext)\n\n  return (\n    <div>\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u306f {color} \u3067\u3059\u3002<\/div>\n  )\n}<\/code><\/pre>\n
    \u3053\u308c\u306b\u3088\u308a\u3001\u4e2d\u9593\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u3044\u304f\u3064\u5b58\u5728\u3057\u3066\u3044\u3088\u3046\u3068\u3001\u76f4\u63a5\u6700\u4e0b\u5c64\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067 state \u3092\u6271\u3048\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n
    SampleContext.Provider \u3092\u4f7f\u7528\u3057\u3066\u3044\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u4ee5\u5916\u306e\u7b87\u6240\u3067 Global state \u3092\u66f4\u65b0\u3057\u305f\u3044\u5834\u5408\u306f\u3001useState \u3092\u4f7f\u7528\u3057 state \u3068\u305d\u308c\u3092\u66f4\u65b0\u3059\u308b\u305f\u3081\u306e\u95a2\u6570\u306e\u4e21\u65b9\u3092 Context.Provider \u306e value \u306b\u6e21\u3057\u3066\u3042\u3052\u308b\u3053\u3068\u3067\u66f4\u65b0\u304c\u53ef\u80fd\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n
    \u4ee5\u4e0b\u306e\u4f8b\u3067\u306f useState \u3092\u4f7f\u7528\u3057\u305f\u30ab\u30b9\u30bf\u30e0\u30d5\u30c3\u30af\u3092\u4f5c\u6210\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n
    import { useState } from 'react'\n\nconst useThemeColor = () => {\n  const [themeColor, setThemeColor] = useState('light')\n\n  return {\n    themeColor,\n    setThemeColor\n  }\n}\n\nexport default useThemeColor<\/code><\/pre>\n
    import { createContext, useContext } from 'react'\nimport useThemeColor from '.\/hooks\/useThemeColor'\n\nconst SampleContext = createContext()\n\nconst Top = () => {\n  return (\n    <SampleContext.Provider value={useThemeColor()}>\n      <Middle \/>\n    <\/SampleContext.Provider>\n  )\n}\n\nconst Middle = () => {\n  return (\n    <Bottom \/>\n  )\n}\n\nconst Bottom = () => {\n  const context = useContext(SampleContext)\n\n  return (\n    \/\/ \u30dc\u30bf\u30f3\u3092\u62bc\u3057\u305f\u6642\u306b context.themeColor \u3092 'dark' \u306b\u66f4\u65b0\u3059\u308b\n    <button onClick={() => context.setThemeColor('dark')}>\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u66f4\u65b0<\/button>\n  )\n}\n<\/code><\/pre>\n
    Global state \u304c\u66f4\u65b0\u3055\u308c\u308b\u305f\u3073\u306b\u3001useContext \u3067\u305d\u306e Context \u3092\u53c2\u7167\u3057\u3066\u3044\u308b\u5168\u3066\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304c\u518d\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\u3055\u308c\u308b\u305f\u3081\u30011\u3064\u306e Context \u3067\u5168\u3066\u306e Global state \u3092\u7ba1\u7406\u3059\u308b\u306e\u3067\u306f\u306a\u304f\u3001\u5fc5\u8981\u306b\u5fdc\u3058\u3066\u8907\u6570\u306e Context \u3092\u7528\u610f\u3059\u308b\u3068\u826f\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n
    \u305d\u306e\u4ed6\u3001React Context \u306b\u3064\u3044\u3066\u306f React \u306e\u516c\u5f0f\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306b\u8a73\u3057\u304f\u66f8\u304b\u308c\u3066\u3044\u308b\u305f\u3081\u3001\u6c17\u306b\u306a\u308b\u65b9\u306f\u662f\u975e\u3054\u89a7\u304f\u3060\u3055\u3044\u3002
    \n\u30b3\u30f3\u30c6\u30ad\u30b9\u30c8\u306e\u30ac\u30a4\u30c9<\/a><\/p>\n
    \u3053\u306e React Context \u3092\u4f7f\u3063\u305f Global state \u306e\u7ba1\u7406\u306f\u3001\u4eca\u56de\u7d39\u4ecb\u3059\u308b\u65b9\u6cd5\u306e\u4e2d\u3067\u6bd4\u8f03\u7684\u304a\u624b\u8efd\u306b\u4f7f\u3046\u3053\u3068\u304c\u3067\u304d\u308b\u306e\u3067\u3001\u5c0f\u898f\u6a21\u306a\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306f\u3053\u306e\u65b9\u6cd5\u3092\u7528\u3044\u308b\u306e\u304c\u826f\u3044\u306e\u3067\u306f\u306a\u3044\u304b\u3068\u601d\u308f\u308c\u307e\u3059\u3002<\/p>\n
    2. Redux<\/h2>\n
    Redux<\/a> \u3068\u306f\u3001React \u304c\u6271\u3046 state \u306e\u7ba1\u7406\u306b\u7279\u5316\u3057\u305f\u30e9\u30a4\u30d6\u30e9\u30ea\u3067\u3042\u308a\u3001\u73fe\u6642\u70b9 (2022 \u5e74 4 \u6708) \u306b\u304a\u3051\u308b React \u306e state \u7ba1\u7406\u306e\u30c7\u30d5\u30a1\u30af\u30c8\u30b9\u30bf\u30f3\u30c0\u30fc\u30c9\u306b\u8fd1\u3044\u30dd\u30b8\u30b7\u30e7\u30f3\u3092\u53d6\u3063\u3066\u3044\u307e\u3059\u3002<\/p>\n
    Redux - npm<\/a> \u3092\u898b\u308b\u3068\u3001Weekly Downloads \u304c 2022 \u5e74 4 \u6708\u306e\u6642\u70b9\u3067\u7d04 780 \u4e07\u3068\u975e\u5e38\u306b\u591a\u304f\u3001\u5168\u4e16\u754c\u3067\u591a\u304f\u306e\u958b\u767a\u8005\u306b\u5229\u7528\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u304c\u5206\u304b\u308a\u307e\u3059\u3002<\/p>\n
    \"\"<\/p>\n
    Redux \u306f\u7279\u306b\u5927\u898f\u6a21\u306a\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306b\u9069\u3057\u3066\u3044\u308b\u3068\u8a00\u308f\u308c\u3066\u3044\u307e\u3059\u3002Redux \u306f Facebook \u304c\u751f\u307f\u51fa\u3057\u305f Flux<\/a> \u3068\u3044\u3046\u30a2\u30fc\u30ad\u30c6\u30af\u30c1\u30e3\u306b\u5247\u3063\u3066\u8a2d\u8a08\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u304c\u7279\u5fb4\u3067\u3059\u3002<\/p>\n
    \u4ee5\u4e0b\u3001\u516c\u5f0f\u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u3088\u308a\u5f15\u7528<\/p>\n
    \"\"<\/p>\n
    Redux \u3067\u306f\u3001Store \u3068\u547c\u3070\u308c\u308b\u5834\u6240\u306b\u5168\u3066\u306e State \u304c\u4fdd\u5b58\u3055\u308c\u307e\u3059\u3002Action \u3092 Dispatch (\u9001\u4fe1) \u3059\u308b\u3053\u3068\u3067 State \u3092\u5b9a\u7fa9\u3057\u305f\u308a\u66f4\u65b0\u3057\u305f\u308a\u3057\u307e\u3059\u3002
    \nStore \u306e\u4e2d\u306e Reducer \u3067 State \u306e\u66f4\u65b0\u3092\u884c\u3044\u307e\u3059\u3002Reducer \u3067 Dispatch \u3055\u308c\u305f Action \u3092\u53d7\u3051\u53d6\u308a\u3001\u65b0\u3057\u3044 State \u3092\u8fd4\u5374\u3057\u307e\u3059\u3002<\/p>\n
    \u5168\u4f53\u306e\u6d41\u308c\u3092\u8aac\u660e\u3059\u308b\u3068\u3001<\/p>\n
      \n
    1. ActionCreator \u304c Action \u3092\u4f5c\u6210\u3059\u308b<\/li>\n
    2. Store \u306b\u5bfe\u3057\u3066 Action \u304c Dispatch\uff08\u9001\u4fe1\uff09\u3055\u308c\u308b<\/li>\n
    3. Dispatch \u3055\u308c\u305f Action \u304c Reducer \u306b\u6e21\u3055\u308c\u308b<\/li>\n
    4. Reducer \u304c\u65b0\u3057\u3044 State \u3092\u751f\u6210\u3059\u308b<\/li>\n
    5. Store \u304b\u3089\u65b0\u3057\u3044 State \u3092\u547c\u3073\u51fa\u3057\u3066\u753b\u9762\u4e0a\u306b\u8868\u793a\u3059\u308b<\/li>\n<\/ol>\n
      \u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n
      Redux \u3092\u5c0e\u5165\u3059\u308b\u3053\u3068\u3067\u3001\u8907\u96d1\u306a state \u306e\u7ba1\u7406\u304c\u53ef\u80fd\u306b\u306a\u308a\u307e\u3059\u304c\u3001\u4e00\u65b9\u3067\u5b66\u7fd2\u30b3\u30b9\u30c8\u304c\u9ad8\u3044\u3068\u3044\u3046\u30c7\u30e1\u30ea\u30c3\u30c8\u304c\u5b58\u5728\u3057\u307e\u3059\u3002
      \n\u305d\u306e\u305f\u3081\u5927\u898f\u6a21\u306a\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306e\u63a1\u7528\u304c\u9069\u3057\u3066\u3044\u308b\u3068\u8003\u3048\u3089\u308c\u307e\u3059\u3002<\/p>\n
      3. Recoil<\/h2>\n
      Recoil<\/a> \u3068\u306f\u3001Facebook \u793e\u304c\u958b\u767a\u3057 2020 \u5e74\u306b\u516c\u958b\u3055\u308c\u305f\u3001\u975e\u5e38\u306b\u65b0\u3057\u3044 state \u7ba1\u7406\u306e\u30e9\u30a4\u30d6\u30e9\u30ea\u3067\u3059\u3002<\/p>\n
      Recoil \u3092\u5229\u7528\u3057\u305f Global state \u306e\u7ba1\u7406\u306f\u5b9f\u88c5\u306e\u30cf\u30fc\u30c9\u30eb\u304c\u3068\u3066\u3082\u4f4e\u304f\u3001React Hooks \u306e useState \u306e\u3088\u3046\u306a\u611f\u899a\u3067\u4f7f\u7528\u3067\u304d\u308b\u70b9\u304c\u5927\u304d\u306a\u7279\u5fb4\u3067\u3059\u3002<\/p>\n
      Recoil \u306f Redux \u3068\u540c\u69d8\u306b\u3001Facebook \u304c\u751f\u307f\u51fa\u3057\u305f Flux<\/a> \u3068\u3044\u3046\u30a2\u30fc\u30ad\u30c6\u30af\u30c1\u30e3\u306b\u5247\u3063\u3066\u8a2d\u8a08\u3055\u308c\u3066\u304a\u308a\u3001Atom \u3084 Selector \u3068\u547c\u3070\u308c\u308b\u5358\u4f4d\u3092\u4f7f\u7528\u3057\u3066\u30c7\u30fc\u30bf\u3092\u7ba1\u7406\u3057\u307e\u3059\u3002<\/p>\n
      \u4eca\u56de\u3082\u30da\u30fc\u30b8\u5168\u4f53\u306e\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u3092 Global state \u3068\u3057\u3066\u6271\u3046\u3053\u3068\u3092\u60f3\u5b9a\u3057\u3066\u3001\u5b9f\u969b\u306b Recoil \u3092\u89e6\u3063\u3066\u307f\u307e\u3059\u3002<\/p>\n
      import { RecoilRoot, atom, useRecoilState } from 'recoil'\n\nconst themeColorState = atom({\n  key: 'themeColorState',\n  default: 'light'\n})\n\nconst Top = () => {\n  return (\n    <RecoilRoot>\n      <Middle \/>\n    <\/RecoilRoot>\n  )\n}\n\nconst Middle = () => {\n  return (\n    <Bottom \/>\n  )\n}\n\nconst Bottom = () => {\n  const [themeColor, setThemeColor] = useRecoilState(themeColorState)\n\n  return (\n    <div>\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u306f {themeColor} \u3067\u3059\u3002<\/div>\n  )\n}<\/code><\/pre>\n
      atom \u306f\u72b6\u614b\u306e\u4e00\u90e8\u3092\u8868\u3057\u3066\u304a\u308a\u3001\u4efb\u610f\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u304b\u3089\u8aad\u307f\u53d6\u308a\u3084\u66f8\u304d\u8fbc\u307f\u3092\u884c\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
      key \u306b\u306f\u4ed6\u306e atom \u3068\u88ab\u3089\u306a\u3044\u3088\u3046\u306a unique ID \u3092\u4ed8\u3051\u3001default \u306b state \u306e\u521d\u671f\u5024\u3092\u5165\u308c\u307e\u3059\u3002<\/p>\n
      const themeColorState = atom({\n  key: 'themeColorState',\n  default: 'light'\n})<\/code><\/pre>\n
      Recoil \u3092\u4f7f\u7528\u3059\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3092 RecoilRoot \u3067\u56f2\u307f\u307e\u3059\u3002\u3053\u308c\u306b\u3088\u308a\u3001\u4ee5\u4e0b\u306e\u4f8b\u3067\u306f Middle \u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3068\u305d\u306e\u914d\u4e0b\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u3067 state \u3092\u547c\u3073\u51fa\u3057\u305f\u308a\u3001\u66f4\u65b0\u3057\u305f\u308a\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
      const Top = () => {\n  return (\n    <RecoilRoot>\n      <Middle \/>\n    <\/RecoilRoot>\n  )\n}<\/code><\/pre>\n
      \u6700\u5f8c\u306b\u3001\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u5185\u3067 useRecoilState \u3092\u4f7f\u3046\u3053\u3068\u3067\u3001state \u306e\u547c\u3073\u51fa\u3057\u3068\u66f4\u65b0\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
      useRecoilState \u304b\u3089\u8fd4\u3055\u308c\u308b\u914d\u5217\u306e1\u3064\u76ee\u306e\u8981\u7d20\u306f state \u306e\u73fe\u5728\u306e\u5024\u3067\u3042\u308a\u30012 \u3064\u76ee\u306e\u8981\u7d20\u306f\u305d\u308c\u3092\u66f4\u65b0\u3059\u308b\u305f\u3081\u306e\u95a2\u6570\u3067\u3059\u3002<\/p>\n
      const Middle = () => {\n  return (\n    <Bottom \/>\n  )\n}\n\nconst Bottom = () => {\n  const [themeColor, setThemeColor] = useRecoilState(themeColorState)\n\n  return (\n    <div>\u30c6\u30fc\u30de\u30ab\u30e9\u30fc\u306f {themeColor} \u3067\u3059\u3002<\/div>\n  )\n}<\/code><\/pre>\n
      Recoil \u3067\u4e00\u756a\u591a\u304f\u4f7f\u3046\u3053\u3068\u306b\u306a\u308b\u3067\u3042\u308d\u3046 useRecoilState \u306f\u3001React Hooks \u306e useState \u3068\u307b\u3068\u3093\u3069\u540c\u3058\u3088\u3046\u306a\u4f7f\u3044\u65b9\u304c\u3067\u304d\u308b\u305f\u3081\u3001\u65e2\u306b React Hooks \u3092\u4f7f\u3044\u3053\u306a\u305b\u3066\u3044\u308b\u4eba\u306f\u975e\u5e38\u306b\u4f4e\u3044\u5b66\u7fd2\u30b3\u30b9\u30c8\u3067 Recoil \u3092\u6271\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
      Recoil \u306f\u307e\u3060\u516c\u958b\u3055\u308c\u3066\u9593\u3082\u306a\u304f\u3001\u73fe\u6642\u70b9 (2022 \u5e74 4 \u6708) \u3067\u306f\u307e\u3060\u5b9f\u9a13\u7684\u306a\u6bb5\u968e\u3067\u3059\u304c\u3001\u4eca\u5f8c state \u7ba1\u7406\u30e9\u30a4\u30d6\u30e9\u30ea\u306e\u4e3b\u6d41\u306b\u306a\u308b\u3068\u3082\u8a00\u308f\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n
      Recoil \u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u306b\u3088\u308a\u7c21\u5358\u306b Global state \u3092\u7ba1\u7406\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308b\u305f\u3081\u3001\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306e\u898f\u6a21\u306b\u3088\u3089\u305a\u975e\u5e38\u306b\u304a\u3059\u3059\u3081\u3067\u3059\u3002<\/p>\n
      4. SWR<\/h2>\n
      SWR<\/a> \u306f Next.js \u3092\u958b\u767a\u3057\u3066\u3044\u308b Vercel \u304c\u958b\u767a\u3057\u305f\u3001\u30c7\u30fc\u30bf\u53d6\u5f97\u306e\u305f\u3081\u306e React Hooks \u30e9\u30a4\u30d6\u30e9\u30ea\u3067\u3059\u3002
      \nSWR \u3068\u3044\u3046\u540d\u524d\u306f       stale-while-revalidate<\/a> \u3068\u3044\u3046\u30ad\u30e3\u30c3\u30b7\u30e5\u6226\u7565\u304b\u3089\u6765\u3066\u3044\u307e\u3059\u3002<\/p>\n
      \u57fa\u672c\u7684\u306a\u4f7f\u3044\u65b9\u3068\u3057\u3066\u306f\u3001useSWR \u3068\u3044\u3046 React Hooks \u3092\u7528\u3044\u308b\u3053\u3068\u3067\u3001API \u3092\u901a\u3058\u305f\u30c7\u30fc\u30bf\u306e\u53d6\u5f97\u30fb\u30ad\u30e3\u30c3\u30b7\u30e5\u3092\u7c21\u5358\u306b\u8a18\u8ff0\u3059\u308b\u624b\u52a9\u3051\u3092\u3057\u3066\u304f\u308c\u307e\u3059\u3002<\/p>\n
      import useSWR from 'swr'\n\nconst fetcher = () => fetch('\/api\/user')\n\nconst Profile = () => {\n  const { data, error } = useSWR('\/api\/user', fetcher)\n\n  if (error) return <div>failed to load<\/div>\n  if (!data) return <div>loading...<\/div>\n  return <div>hello {data.name}!<\/div>\n}<\/code><\/pre>\n
      useSWR \u30d5\u30c3\u30af\u306f key \u6587\u5b57\u5217\u3068 fetcher \u95a2\u6570\u3092\u53d7\u3051\u53d6\u308a\u307e\u3059\u3002 key \u306f\u30c7\u30fc\u30bf\u306e\u4e00\u610f\u306a\u8b58\u5225\u5b50\u3067\u3001fetcher \u306b\u5f15\u6570\u3068\u3057\u3066\u6e21\u3055\u308c\u307e\u3059\u3002 fetcher \u306f\u30c7\u30fc\u30bf\u3092\u8fd4\u3059\u4efb\u610f\u306e\u975e\u540c\u671f\u95a2\u6570\u3067\u3001fetch \u3084 Axios \u306e\u3088\u3046\u306a\u30c4\u30fc\u30eb\u3092\u4f7f\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
      \u901a\u5e38\u306f\u3053\u306e\u3088\u3046\u306b\u3001API \u3092\u901a\u3058\u3066\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3059\u308b\u305f\u3081\u306b\u4f7f\u7528\u3057\u307e\u3059\u3002
      \n\u3057\u304b\u3057\u7b2c\u4e8c\u5f15\u6570\u306e fetcher \u3092\u6e21\u3059\u7b87\u6240\u306b null \u3092\u6e21\u3059\u3053\u3068\u306b\u3088\u308a\u3001useSWR \u3067 Global state \u306e\u7ba1\u7406\u304c\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n
      const { data: themeColor, mutate: setThemeColor } = useSWR('themeColor', null, { initialData: 'light' });<\/code><\/pre>\n
      useSWR \u304b\u3089\u8fd4\u3063\u3066\u304f\u308b data \u306f\u30c7\u30fc\u30bf\u306e\u73fe\u5728\u306e\u5024\u3067\u3042\u308a\u3001mutate \u95a2\u6570\u3092\u4f7f\u7528\u3059\u308b\u3053\u3068\u3067\u30c7\u30fc\u30bf\u3092\u66f4\u65b0\u3067\u304d\u308b\u305f\u3081\u3001React Hooks \u306e useState \u306e\u3088\u3046\u306a\u4f7f\u3044\u65b9\u304c\u3067\u304d\u307e\u3059\u3002
      \n\u305d\u306e\u305f\u3081\u3001\u3053\u3061\u3089\u3082\u4f4e\u3044\u5b66\u7fd2\u30b3\u30b9\u30c8\u3067\u6271\u3046\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n
      \u307e\u305f\u3001useSWR \u306e\u7b2c\u4e09\u5f15\u6570\u306b\u306f\u69d8\u3005\u306a option \u3092\u6307\u5b9a\u3067\u304d\u3001initialData \u3067\u306f data \u306e\u521d\u671f\u5024\u3092\u6307\u5b9a\u3067\u304d\u307e\u3059\u3002<\/p>\n
      \u65e2\u306b\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u5185\u3067\u30c7\u30fc\u30bf\u306e\u53d6\u5f97\u7528\u3068\u3057\u3066 SWR \u3092\u5c0e\u5165\u3057\u3066\u3044\u308b\u5834\u5408\u306b\u3001Global state \u7ba1\u7406\u306e\u305f\u3081\u306b SWR \u3092\u4f7f\u7528\u3059\u308b\u3068\u3044\u3046\u306e\u304c\u826f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n
      \u307e\u3068\u3081<\/h2>\n
      React \u306b\u304a\u3051\u308b Global state \u306e\u7ba1\u7406\u6cd5\u30924\u3064\u3054\u7d39\u4ecb\u3057\u307e\u3057\u305f\u3002
      \n\u500b\u4eba\u7684\u306b\u306f\u3001\u73fe\u5728\u5e45\u5e83\u304f\u4f7f\u7528\u3055\u308c\u3066\u3044\u308b SWR \u3084\u7c21\u5358\u306b\u6271\u3046\u3053\u3068\u306e\u3067\u304d\u308b Recoil \u3092\u304a\u3059\u3059\u3081\u3057\u307e\u3059\u304c\u3001\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u5c0e\u5165\u305b\u305a\u306b\u4f7f\u7528\u3067\u304d\u308b React Context \u3084\u3001\u8907\u96d1\u306a state \u7ba1\u7406\u304c\u53ef\u80fd\u3068\u306a\u308b Redux \u306a\u3069\u3001\u81ea\u8eab\u306e\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u306b\u5408\u3063\u305f Global state \u306e\u7ba1\u7406\u6cd5\u3092\u5c0e\u5165\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
      \u3053\u306e\u6295\u7a3f\u306f\u3001\u5f0a\u793e\u304c\u63d0\u4f9b\u3059\u308bWESEEK TECH\u901a\u4fe1\u306e\u4e00\u74b0\u3067\u3059\u3002 WESEEK TECH\u901a\u4fe1\u3068\u306f\u3001WESEEK\u306e\u30a8\u30f3\u30b8\u30cb\u30a2\u304c\u30ad\u30e3\u30c3\u30c1\u30a2\u30c3\u30d7\u3057\u305f\u6280\u8853\u306b\u95a2\u3059\u308b\u60c5\u5831\u3092\u3001tech\u30d6\u30ed\u30b0\u3092\u901a\u3058\u3066\u5b9a\u671f\u7684\u306b\u767a\u4fe1\u3057\u3066\u3044\u304f\u3082\u306e\u3067\u3059\u3002 \u306f\u3058<\/p>\n","protected":false},"author":4,"featured_media":2569,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[31,51],"tags":[],"_links":{"self":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts\/2565"}],"collection":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/comments?post=2565"}],"version-history":[{"count":27,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts\/2565\/revisions"}],"predecessor-version":[{"id":2768,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/posts\/2565\/revisions\/2768"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/media\/2569"}],"wp:attachment":[{"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/media?parent=2565"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/categories?post=2565"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/weseek.co.jp\/tech\/wp-json\/wp\/v2\/tags?post=2565"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}