vue-translator

A deadly simple i18n translate plugin for Vue, ready for Server Side Rendering.

Demo

client side rendering: https://JounQin.github.io/vue-translator

server side rendering: https://rubick.1stg.me (source code)

Usage

yarn add vue-translator

Basic Usage

import Vue from 'vue'
import VueTranslator from 'vue-translator'

Vue.use(VueTranslator, {
  locale?: string, // set it on initialize or before first rendering
  translations?: {  // If you want to define translations in component only, no need to set it on initialize
    [locale: string]: {
      [key:string]: string | array | object
    }
  },
  defaultLocale?: string, // when no value can be found in current locale, try to fallback to defaultLocale
  filter?: boolean | string, // whether to enable filter `translate` or custom define filter name (>= 0.7.0)
  merge?: Function // `lodash.merge` for example, if you want to use component translator you must pass it
})

You will get a default translator instance on Vue.translator, it is safe to use it on client, but please avoid use it on server, be careful!

translations is often generated via require.context provided by webpack from *.{locale}.i18n.json:

const context = require.context('.', true, /([\w-]*[\w]+)\.i18n\.json$/)

const LOCALE_KEYS: { [key: string]: string[] } = {}

const translations: {
  [locale: string]: {
    [key: string]: string
  }
} = context.keys().reduce((modules: any, key: string) => {
  const module = context(key)
  const lang = key.match(/([\w-]*[\w]+)\.i18n\.json$/)[1]
  const matched = modules[lang] || (modules[lang] = {})

  if (process.env.NODE_ENV === 'development') {
    const keys = LOCALE_KEYS[lang] || (LOCALE_KEYS[lang] || [])
    const moduleKeys = Object.keys(module)

    const duplicates = _.intersection(keys, moduleKeys)

    if (duplicates.length) {
      console.warn('detect duplicate keys:', duplicates)
    }

    keys.push(...moduleKeys)
  }

  Object.assign(matched, module)
  return modules
}, {})

Then you will be able to use $t in all your component template.

<template>
  <div>
    {{ $t('message', obj_params?) }}
    {{ $t('nested.message', arr_params?) }}
  </div>
</template>
<script>
export default {
  name: 'custom-component', // it is needed for better cache for < 0.6.0, after >= 0.6.0 not required
  translator: {
    zh: {
      message: '我的信息',
    },
    en: {
      message: 'My Message',
    },
  },
}
</script>

If you are trying to get a non-exist key or value is undefined, you will get a warning in console on development. And if you want to ignore it, pass a third parameter ignoreNonExist: boolean: $t('non-exist-key', null, true).

If you want to watch locale change in any component, global watch should be defined on root component:

new Vue({
  el: '#app',
  watch: {
    '$t.locale'(curr, prev) {
      // do something
    },
  },
})

Or you want to change locale on client:

{
  methods: {
    changeLocale() {
      this.$t.locale = 'locale'
    }
  }
}

SSR related

You'd better to detect user custom locale via cookie and fallback to accept-language on first request.

And you need to generate a single translator instance for every user request (cache by locale would be better) via createTranslator, koa for example:

import { createTranslator } from 'vue-translator'

app.use(async (ctx, next) => {
  const translator = createTranslator({
    locale: string, // ctx.cookies.get('locale_cookie')
    defaultLocale: string,
  })

  const context = {} // user context

  context.translator = translator

  // ... do anything
})

Then $t will be translator generated above, if you don't mind user's locale cookie and not pass translator instance into user context, it will fallback to the default translator.

Remember, always get translator instance via this.$t of context.translator instead of Vue.translator unless you are not handling user request.

And notice implement of filter translate on server is a little hacky which overwrites Vue.prototype._f internally to get this.$t for every request.

template syntax

Translation key should be string, but .(dot) will be parsed as nested key, it will also work in template!

$t('a.b.c') // will try to find `a.b.c` on your custom transition, if a is falsy, will render undefined and try default locale

// render `nested value`
new Vue({
  translator: {
    en: {
      a: {
        b: {
          c: 'nested value',
        },
      },
    },
  },
})

// render `nested template`
$t('a.b', {c: d: 'nested template'})
new Vue({
  translator: {
    en: {
      a: {
        b: '{ c.d }'
      },
    },
  },
})

Array is also supported, .index(dot) or [index] can both be used!

// nested with array key and template
// render `1`
$t('a.b[0]', [{ a: 1 }])

new Vue({
  translator: {
    en: {
      a: {
        b: ['{ 0.a }'], // do not use `[0].a` here, `0[a]` is also OK
      },
    },
  },
})

Feature Request or Troubleshooting

Feel free to create an issue.