Internationalization is a design process that ensures a product (a website or application) can be adapted to various languages and regions without requiring engineering changes to the source code. Think of internationalization as readiness for localization.

Setup manually

If you missed enabling i18n during yarn create quasar (or npm init quasar) wizard, here is how you can set it up manually.

1. Install the vue-i18n dependency into your app.

$ yarn add vue-i18n@next
// or:
$ npm install vue-i18n@next

2. Create a file src/boot/i18n.js with following content:

import { createI18n } from 'vue-i18n'
import messages from 'src/i18n'

export default ({ app }) => {
  // Create I18n instance
  const i18n = createI18n({
    locale: 'en-US',
    globalInjection: true,
    messages
  })

  // Tell app to use the I18n instance
  app.use(i18n)
}

3. Create a folder (/src/i18n/) in your app which will hold the definitions for each language that you’ll support. Example: src/i18n. Notice the “import messages from ‘src/i18n’” from step 2. This is step where you write the content that gets imported.

4. Now reference this file in quasar.config.js in the boot section:

// quasar.config.js
return {
  boot: [
    // ...
    'i18n'
  ],

  // ...
}

Now you are ready to use it in your pages.

Setting up Translation Blocks in your SFCs

If we want to add support to the <i18n> tag inside a SFC (single file component) in a Quasar CLI project then we need to modify the existing configuration.

We first install the @intlify/vue-i18n-loader package:

$ yarn add --dev @intlify/vue-i18n-loader
# or
$ npm i --save-dev @intlify/vue-i18n-loader

We then edit quasar.config.js at the root of our project. We have to include the following:

// quasar.config.js

const path = require('path')

build: {
  chainWebpack: chain => {
    chain.module
      .rule('i18n-resource')
        .test(/\.(json5?|ya?ml)$/)
          .include.add(path.resolve(__dirname, './src/i18n'))
          .end()
        .type('javascript/auto')
        .use('i18n-resource')
          .loader('@intlify/vue-i18n-loader')
    chain.module
      .rule('i18n')
        .resourceQuery(/blockType=i18n/)
        .type('javascript/auto')
        .use('i18n')
          .loader('@intlify/vue-i18n-loader')
  }
}

How to use

There are 3 main cases:

<template>
  <q-page>
    <q-btn :label="$t('mykey2')">
    {{ $t('mykey1') }}
    <span v-html="content"></span>
  </q-page>
</template>

<script>
export default {
  data() {
    return {
      content: this.$t('mykey3')
    }
  }
}
</script>

1. mykey1 in HTML body
2. mykey2 in attribute
3. mykey3 programmatically

Add new language

Let’s say you want to add new German language.

1. Create the new file src/i18n/de/index.js and copy there the content of the file src/i18n/en-US/index.js then make changes to the language strings.
2. Now change src/i18n/index.js and add the new de language there.

import enUS from './en-US'
import de from './de'

export default {
  'en-US': enUS,
  'de': de
}

Create language switcher

<!-- some .vue file -->

<template>
  <!-- ...... -->
  <q-select
    v-model="locale"
    :options="localeOptions"
    label="Quasar Language"
    dense
    borderless
    emit-value
    map-options
    options-dense
    style="min-width: 150px"
  />
  <!-- ...... -->
</template>

<script>
import { useI18n } from 'vue-i18n'

export default {
  setup () {
    const { locale } = useI18n({ useScope: 'global' })

    return {
      locale,
      localeOptions: [
        { value: 'en-US', label: 'English' },
        { value: 'de', label: 'German' }
      ]
    }
  }
}
</script>

UPPERCASE

Many languages, such as Greek, German and Dutch have non-intuitive rules for uppercase display, and there is an edge case that you should be aware of:

QBtn component will use the CSS text-transform: uppercase rule to automatically turn its label into all-caps. According to the MDN webdocs, “The language is defined by the lang HTML attribute or the xml:lang XML attribute.” Unfortunately, this has spotty implementation across browsers, and the 2017 ISO standard for the uppercase German eszett ß has not really entered the canon. At the moment you have two options:

1. use the prop no-caps in your label and write the string as it should appear
2. use the prop no-caps in your label and rewrite the string with toLocaleUpperCase by using the locale as detected by $q.lang.getLocale()

Detecting Locale

There’s also a method to determine user locale which is supplied by Quasar out of the box:

// outside of a Vue file
import { Quasar } from 'quasar'
Quasar.lang.getLocale() // returns a string

// inside of a Vue file
import { useQuasar } from 'quasar'

setup () {
  const $q = useQuasar()
  $q.lang.getLocale() // returns a string
}