react 国际化的实现代码示例
背景
楼主最近新接了一个项目,从0开始做,需要做多语言的国际化,今天搞了一下,基本达到了想要的效果, 在这里简单分享下:
一些探索
也说不上是探索吧,就Google了一波, 去gayHub 上找了一个比较成熟的库 react-i18next
, 写了一些代码,现将过程分享一下, 附带详细代码,手把手教你实现国际化。
先睹为快
先看一下最后的成果:
// ... import i18n from '@src/i18n'; // xxx component console.log('哈哈哈哈哈i18n来一发:', i18n.t('INVALID_ORDER')); // ... render() { // ... <button> {i18n.t('INVALID_ORDER')} <button> }
控制台中:
对应json 中的信息:
开始
原理
原理其实很简单: 字符串替换。
拉取远程的国际化json文件到本地,再根据语言做一个映射就可以了。
废话不多说, 来看代码吧。
先简单看一下目录结构:
先看一下 config
里面的 相关代码:
env.js
:
'use strict'; const fs = require('fs'); const path = require('path'); const paths = require('./paths'); const languages = require('./languages'); // Make sure that including paths.js after env.js will read .env variables. delete require.cache[require.resolve('./paths')]; const NODE_ENV = process.env.NODE_ENV; if (!NODE_ENV) { throw new Error( 'The NODE_ENV environment variable is required but was not specified.' ); } // https://github.com/bkeepers/dotenv#what-other-env-files-can-i-use var dotenvFiles = [ `${paths.dotenv}.${NODE_ENV}.local`, `${paths.dotenv}.${NODE_ENV}`, // Don't include `.env.local` for `test` environment // since normally you expect tests to produce the same // results for everyone NODE_ENV !== 'test' && `${paths.dotenv}.local`, paths.dotenv, ].filter(Boolean); // Load environment variables from .env* files. Suppress warnings using silent // if this file is missing. dotenv will never modify any environment variables // that have already been set. Variable expansion is supported in .env files. // https://github.com/motdotla/dotenv // https://github.com/motdotla/dotenv-expand dotenvFiles.forEach(dotenvFile => { if (fs.existsSync(dotenvFile)) { require('dotenv-expand')( require('dotenv').config({ path: dotenvFile, }) ); } }); // We support resolving modules according to `NODE_PATH`. // This lets you use absolute paths in imports inside large monorepos: // https://github.com/facebookincubator/create-react-app/issues/253. // It works similar to `NODE_PATH` in Node itself: // https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders // Note that unlike in Node, only *relative* paths from `NODE_PATH` are honored. // Otherwise, we risk importing Node.js core modules into an app instead of Webpack shims. // https://github.com/facebookincubator/create-react-app/issues/1023#issuecomment-265344421 // We also resolve them to make sure all tools using them work consistently. const appDirectory = fs.realpathSync(process.cwd()); process.env.NODE_PATH = (process.env.NODE_PATH || '') .split(path.delimiter) .filter(folder => folder && !path.isAbsolute(folder)) .map(folder => path.resolve(appDirectory, folder)) .join(path.delimiter); // Grab NODE_ENV and REACT_APP_* environment variables and prepare them to be // injected into the application via DefinePlugin in Webpack configuration. const REACT_APP = /^REACT_APP_/i; function getClientEnvironment(publicUrl) { const raw = Object.keys(process.env) .filter(key => REACT_APP.test(key)) .reduce( (env, key) => { env[key] = process.env[key]; return env; }, { // Useful for determining whether we're running in production mode. // Most importantly, it switches React into the correct mode. NODE_ENV: process.env.NODE_ENV || 'development', // Useful for resolving the correct path to static assets in `public`. // For example, <img src={process.env.PUBLIC_URL + '/img/logo.png'} />. // This should only be used as an escape hatch. Normally you would put // images into the `src` and `import` them in code to get their paths. PUBLIC_URL: publicUrl, LANGUAGE: { resources: languages.resources, defaultLng: languages.defaultLng }, COUNTRY: process.env.COUNTRY } ); // Stringify all values so we can feed into Webpack DefinePlugin const stringified = { 'process.env': Object.keys(raw).reduce((env, key) => { env[key] = JSON.stringify(raw[key]); return env; }, {}), }; return { raw, stringified }; } module.exports = getClientEnvironment;
主要看lannguage 相关的代码就好了, 其他的都create-react-app
的相关配置, 不用管。
再看下 language.js
里面的逻辑:
const path = require('path'); const paths = require('./paths'); const localesHash = require('../i18n/localesHash'); const resourcesHash = require('../i18n/resourcesHash'); const COUNTRY = process.env.COUNTRY || 'sg'; const country = (COUNTRY).toUpperCase(); const defaultLng = localesHash[country][0]; const langs = [ 'en', 'id' ]; const prefixLangs = []; const entries = {}; for (let i = 0, len = langs.length; i < len; i++) { const prefixLang = `dict_${langs[i]}` prefixLangs.push(prefixLang) entries[prefixLang] = path.resolve(paths.appSrc, `../i18n/locales/${langs[i]}.json`) } const resources = { [defaultLng]: { common: resourcesHash[defaultLng] } } exports.resources = resources; exports.defaultLng = defaultLng;
逻辑也比较简单, 根据语言列表把对应的json 内容加进来。 作为示例,这里我设置的是 英文 和 印尼语。
下面看 i18n
文件里面的内容:
locales
里面放的是语言的json 文件, 内容大概是:
{ "msg_Created": "Pesanan telah terbuat" // ... }
localesHash.js
:
module.exports = { SG: ['en'], ID: ['id'] }
resourcesHash.js
:
module.exports = { 'en': require('./locales/en.json'), 'id': require('./locales/id.json') }
index.js
const path = require('path') const fs = require('fs') const fetch = require('isomorphic-fetch') const localesHash = require('./localesHash') const argv = process.argv.slice(2) const country = (argv[0] || '').toUpperCase() const i18nServerURI = locale => { const keywords = { 'en': 'en', 'id': 'id' } const keyword = keywords[locale] return keyword === 'en' ? 'xxx/json/download' : `/${keyword}/json/download` } const fetchKeys = async (locale) => { const uri = i18nServerURI(locale) console.log(`Downloading ${locale} keys...\n${uri}`) const respones = await fetch(uri) const keys = await respones.json() return keys } const access = async (filepath) => { return new Promise((resolve, reject) => { fs.access(filepath, (err) => { if (err) { if (err.code === 'EXIST') { resolve(true) } resolve(false) } resolve(true) }) }) } const run = async () => { const locales = localesHash[country] || Object .values(localesHash) .reduce( (previous, current) => previous.concat(current), [] ) if (locales === undefined) { console.error('This country is not in service.') return } for (const locale of locales) { const keys = await fetchKeys(locale) const data = JSON.stringify(keys, null, 2) const directoryPath = path.resolve(__dirname, 'locales') if (!fs.existsSync(directoryPath)) { fs.mkdirSync(directoryPath) } const filepath = path.resolve(__dirname, `locales/${locale}.json`) const isExist = await access(filepath) const operation = isExist ? 'update' : 'create' console.log(operation) fs.writeFileSync(filepath, `${data}\n`) console.log(`${operation}\t${filepath}`) } } run();
再看下src
中的配置:
i18nn.js
import i18next from 'i18next' import { firstLetterUpper } from './common/helpers/util'; const env = process.env; let LANGUAGE = process.env.LANGUAGE; LANGUAGE = typeof LANGUAGE === 'string' ? JSON.parse(LANGUAGE) : LANGUAGE const { defaultLng, resources } = LANGUAGE i18next .init({ lng: defaultLng, fallbackLng: defaultLng, defaultNS: 'common', keySeparator: false, debug: env.NODE_ENV === 'development', resources, interpolation: { escapeValue: false }, react: { wait: false, bindI18n: 'languageChanged loaded', bindStore: 'added removed', nsMode: 'default' } }) function isMatch(str, substr) { return str.indexOf(substr) > -1 || str.toLowerCase().indexOf(substr) > -1 } export const changeLanguage = (locale) => { i18next.changeLanguage(locale) } // Uppercase the first letter of every word. abcd => Abcd or abcd efg => Abcd Efg export const tUpper = (str, allWords = true) => { return firstLetterUpper(i18next.t(str), allWords) } // Uppercase all letters. abcd => ABCD export const tUpperCase = (str) => { return i18next.t(str).toUpperCase() } export const loadResource = lng => { let p; return new Promise((resolve, reject) => { if (isMatch(defaultLng, lng)) resolve() switch (lng) { case 'id': p = import('../i18n/locales/id.json') break default: p = import('../i18n/locales/en.json') } p.then(data => { i18next.addResourceBundle(lng, 'common', data) changeLanguage(lng) }) .then(resolve) .catch(reject) }) } export default i18next
// firstLetterUpper export const firstLetterUpper = (str, allWords = true) => { let tmp = str.replace(/^(.)/g, $1 => $1.toUpperCase()) if (allWords) { tmp = tmp.replace(/\s(.)/g, $1 => $1.toUpperCase()) } return tmp; }
这些准备工作做好后, 还需要把i18n 注入到app中:
index.js
:
import React from 'react'; import { render } from 'react-dom'; import { Provider } from 'react-redux'; import rootReducer from './common/redux/reducers'; import { configureStore } from './common/redux/store'; import { Router } from 'react-router-dom'; import createBrowserHistory from 'history/createBrowserHistory'; import { I18nextProvider } from 'react-i18next'; import i18n from './i18n'; import './common/styles/index.less'; import App from './App'; export const history = createBrowserHistory(); const ROOT = document.getElementById('root'); render( <I18nextProvider i18n={i18n}> <Provider store={configureStore(rootReducer)} > <Router history={history}> <App /> </Router> </Provider> </I18nextProvider>, ROOT );
如何使用
加入上面的代码后, 控制台会有一些log 信息, 表示语言已经加载好了。
在具体的业务组件中,使用方法是:
// ... import i18n from '@src/i18n'; console.log('哈哈哈哈哈i18n来一发:', i18n.t('INVALID_ORDER'));
控制台中:
对应json 中的信息:
后面你就可以愉快的加各种词条了。
Tips
我们在src 中的文件中引入了src 目录外的文件, 这是create-react-app 做的限制, 编译会报错, 把它去掉就好了:
结语
这里作为例, 就是把语言的json 文件下载下来放到locales 目录里, 如果想实时拉取,要保证文件下载完之后再render app.
类似:
loadResource(getLocale()) .then(() => { import('./app.js') })
当然你也可以免了这一步,直接下载好放到工程里来。