Migration ways

vue-i18n-bridge

What is vue-i18n-bridge?

vue-i18n-bridge is a bridge to make the upgrade as easy as possible between vue-i18n@v8.26.1 or later and vue-i18n@v9.x.

It can be used in Vue 2 applications that you have already built with vue-i18n@v8.26.1 or later.

And, also some features are backported from vue-i18n@v9.x:

  • Vue I18n Compostion API, that is powered by @vue/composition-api
  • Message format syntax, that is powered by @intlify/message-compiler

Installation

Package manager

# npm
npm install vue-i18n-bridge
# yarn
yarn add vue-i18n-bridge
# pnpm
pnpm add vue-i18n-bridge

You must install the below packages before using this library:

  • vue-i18n: >= v8.26.1 < v9
  • @vue/composition-api: >= v1.2.0

CDN

Include vue-i18n-bridge after vue, @vue/composition-api and it will install.

<script src="https://cdn.jsdelivr.net/npm/vue@2.6"></script>
<script src="https://unpkg.com/vue-i18n@8/dist/vue-i18n.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/@vue/composition-api@1.2"></script>
<script src="https://unpkg.com/vue-i18n-bridge@9.2.0-beta.11/dist/vue-i18n-bridge.global.prod.js"></script>

Usage

Composition API

import Vue from 'vue'
import VueCompositionAPI, { createApp } from '@vue/composition-api'
import { createI18n, useI18n } from 'vue-i18n-bridge'

Vue.use(VueCompositionAPI)
Vue.use(VueI18n, { bridge: true }) // you must specify '{ bridge: true }' plugin option when install vue-i18n

// `createI18n` options is almost same vue-i18n-next (vue-i18n@v9.x) API
const i18n = createI18n({
  legacy: false,
  locale: 'ja',
  messages: {
    en: {
      message: {
        hello: 'hello, {name}!'
      }
    },
    ja: {
      message: {
        hello: 'こんにちは、{name}!'
      }
    }
  }
}, VueI18n) // `createI18n` which is provide `vue-i18n-bridge` has second argument, you **must** pass `VueI18n` constructor which is provide `vue-i18n`

const app = createApp({
 setup() {
   // `useI18n` options is almost same vue-i18n-next (vue-i18n@v9.x) API
   const { t, locale } = useI18n()
   // ... todo something

   return { t, locale }
 }
})

app.use(i18n) // you must install `i18n` instance which is created by `createI18n`
app.mount('#app')

Legacy API

import Vue from 'vue'
import VueCompositionAPI from '@vue/composition-api'
import { createI18n, useI18n } from 'vue-i18n-bridge'

Vue.use(VueCompositionAPI)
Vue.use(VueI18n, { bridge: true }) // you must specify '{ bridge: true }' plugin option when install vue-i18n

// `createI18n` options is almost same vue-i18n-next (vue-i18n@v9.x) API
const i18n = createI18n({
  locale: 'ja',
  messages: {
    en: {
      message: {
        hello: 'hello, {name}!'
      }
    },
    ja: {
      message: {
        hello: 'こんにちは、{name}!'
      }
    }
  }
}, VueI18n) // `createI18n` which is provide `vue-i18n-bridge` has second argument, you **must** pass `VueI18n` constructor which is provide `vue-i18n`

Vue.use(i18n) // you must install `i18n` instance which is created by `createI18n`

const app = new Vue({ i18n })
app.$mount('#app')

for TypeScript:

import Vue from 'vue'
import VueCompositionAPI from '@vue/composition-api'
import { createI18n, useI18n, castToVueI18n } from 'vue-i18n-bridge'

Vue.use(VueCompositionAPI)
Vue.use(VueI18n, { bridge: true })

// you need to cast `i18n` instance
const i18n = castToVueI18n(createI18n({
  locale: 'ja',
  messages: {
    en: {
      message: {
        hello: 'hello, {name}!'
      }
    },
    ja: {
      message: {
        hello: 'こんにちは、{name}!'
      }
    }
  }
}, VueI18n))

Vue.use(i18n)

const app = new Vue({ i18n })
app.$mount('#app')

Usage UMD module in browser

const { createApp } = VueCompositionAPI // exported UMD which is named by `VueCompositionAPI
const { createI18n, useI18n } = VueI18nBridge // exported UMD which is named by `VueI18nBridge`

Vue.use(VueCompositionAPI)
Vue.use(VueI18n, { bridge: true })

Limitations

  • In Legacy API mode, You cannot use new message format syntax by porting from vue-i18n-next
    • it use possible only Composition API mode
  • In Legacy API mode, You cannot use back-ported components that are following components by porting from vue-i18n-next
    • Translation components: <i18n-t>
    • DateTime format components: <i18n-d>
    • Number format components: <i18n-n>

Explanation of Different Builds

In the dist/ directory of the npm package you will find many different builds of vue-i18n-bridge. Here is an overview of which dist file should be used depending on the use-case.

From CDN or without a Bundler

  • vue-i18n-bridge(.runtime).global(.prod).js:
    • For direct use via <script src="..."> in the browser. Exposes the VueI18nBridge global
    • In-browser message format compilation:
      • vue-i18n-bridge.global.js is the "full" build that includes both the compiler and the runtime so it supports compiling message formats on the fly
      • vue-i18n-bridge.runtime.global.js contains only the runtime and requires message formats to be pre-compiled during a build step
    • Inlines all Vue I18n core internal packages - i.e. it’s a single file with no dependencies on other files. This means you must import everything from this file and this file only to ensure you are getting the same instance of code
    • Contains hard-coded prod/dev branches, and the prod build is pre-minified. Use the *.prod.js files for production

NOTICE

Global builds are not UMD builds. They are built as IIFEs and are only meant for direct use via <script src="...">.

  • vue-i18n-bridge(.runtime).esm-browser(.prod).js:
    • For usage via native ES modules imports (in browser via <script type="module">)
    • Shares the same runtime compilation, dependency inlining and hard-coded prod/dev behavior with the global build

With a Bundler

  • vue-i18n-bridge(.runtime).esm-bundler.js:
    • For use with bundlers like webpack, rollup and parcel
    • Leaves prod/dev branches with process\.env\.NODE_ENV guards (must be replaced by bundler)
    • Does not ship minified builds (to be done together with the rest of the code after bundling)
    • Imports dependencies (e.g. @intlify/core-base, @intlify/message-compiler)
      • Imported dependencies are also esm-bundler builds and will in turn import their dependencies (e.g. @intlify/message-compiler imports @intlify/shared)
      • This means you can install/import these deps individually without ending up with different instances of these dependencies, but you must make sure they all resolve to the same version
    • In-browser locale messages compilation:
      • vue-i18n-bridge.runtime.esm-bundler.js is runtime only, and requires all locale messages to be pre-compiled. This is the default entry for bundlers (via module field in package.json) because when using a bundler templates are typically pre-compiled (e.g. in *.json files)
      • vue-i18n-bridge.esm-bundler.js (default): includes the runtime compiler. Use this if you are using a bundler but still want locale messages compilation (e.g. templates via inline JavaScript strings). To use this build, change your import statement to: import { createI18n } from "vue-i18n-bridge/dist/vue-i18n-bridge.esm-bundler.js";

NOTICE

If you use vue-i18n-bridge.runtime.esm-bundler.js, you will need to precompile all locale messages, and you can do that with .json (.json5) or .yaml, i18n custom blocks to manage i18n resources. Therefore, you can be going to pre-compile all locale messages with bundler and the following loader / plugin.

For Node.js (Server-Side)

  • vue-i18n-bridge.cjs(.prod).js:
    • For use in Node.js via require()
    • If you bundle your app with webpack with target: 'node' and properly externalize vue-i18n-bridge, this is the build that will be loaded
    • The dev/prod files are pre-built, but the appropriate file is automatically required based on process\.env\.NODE_ENV

vue-i18n-composable

Composition API is supported from Vue 3, and you can use the official @vue/composition-api plugin to make the Composition API available to Vue 2.

Vue I18n Composition API is also available in Vue 2 using the vue-i18n-composable plugin.

About how to usage, See the here

NOTICE

vue-i18n-composable allows the main API of Vue I18n v8.x to work with the Composition API. All of Composition API provided in Vue I18n v9 are not available.