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， GitHub 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(‘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/${langs[i]}.json`)
}
const resources = {
[defaultLng]: {
common: resourcesHash[defaultLng]
}
}
exports.resources = resources;
exports.defaultLng = defaultLng;
逻辑也比较简单， 根据语言列表把对应的json 内容加进来。 作为示例，这里我设置的是 英文 和 印尼语。
下面看 i18n 文件里面的内容：
locales 里面放的是语言的json 文件， 内容大概是：
{
"msg_Created": "Pesanan telah terbuat"
// ...
}localesHash.js:
module.exports = {
SG: [‘en‘],
ID: [‘id‘]
}
resourcesHash.js:
module.exports = {
‘en‘: require(‘./locales/en.json‘),
‘id‘: require(‘./locales/id.json‘)
}
index.js
const path = require(‘path‘)
const fs = require(‘fs‘)
const fetch = require(‘isomorphic-fetch‘)
const localesHash = require(‘./localesHash‘)
const argv = process.argv.slice(2)
const country = (argv[0] || ‘‘).toUpperCase()
const i18nServerURI = locale => {
const keywords = {
‘en‘: ‘en‘,
‘id‘: ‘id‘
}
const keyword = keywords[locale]
return keyword === ‘en‘
? ‘your/transify/website/json/download‘
: `your/transify/website/${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：
关于多语言的设置
代码示例：
i18next.init({
lng: ‘en‘,
});初始化的时候可以设置默认语言， 如需要切换系统语言， 可以调用 i18n 提供的方法：
import { changeLanguage } from ‘@src/i18n‘;
// ...
// 设置为印尼语
changeLanguage(‘id‘);为了保存语言设置, 可以把 language 保存在 localStorage 中, 使用的时候直接从 storage 里取。
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。
大概就是这样，以上就是实现国际化的全部代码，希望对大家有所帮助。
