i18n Localization

MStore Dashboard mendukung 3 bahasa menggunakan @nuxtjs/i18n: English, Bahasa Indonesia, dan Japanese.

Configuration

// nuxt.config.ts
export default defineNuxtConfig({
  modules: ['@nuxtjs/i18n'],

  i18n: {
    locales: [
      { code: 'en', name: 'English', file: 'en.json' },
      { code: 'id', name: 'Bahasa Indonesia', file: 'id.json' },
      { code: 'ja', iso: 'ja-JP', name: '日本語', file: 'ja.json' }
    ],
    defaultLocale: 'id',
    strategy: 'no_prefix',      // No URL prefix
    detectBrowserLanguage: false, // Disable auto-detection
    restructureDir: '.',
    langDir: 'locales',
    lazy: true                  // Lazy load translations
  }
})

Locale Files Structure

locales/
├── en.json     # English translations
├── id.json     # Indonesian translations
└── ja.json     # Japanese translations

Example Locale Files

// locales/en.json
{
  "common": {
    "save": "Save",
    "cancel": "Cancel",
    "delete": "Delete",
    "edit": "Edit",
    "search": "Search",
    "loading": "Loading...",
    "noData": "No data available"
  },
  "auth": {
    "login": "Login",
    "logout": "Logout",
    "email": "Email",
    "password": "Password",
    "forgotPassword": "Forgot Password?",
    "loginSuccess": "Login successful",
    "loginFailed": "Login failed"
  },
  "inventory": {
    "title": "Inventory",
    "addProduct": "Add Product",
    "productName": "Product Name",
    "sku": "SKU",
    "price": "Price",
    "stock": "Stock",
    "category": "Category"
  },
  "validation": {
    "required": "This field is required",
    "email": "Please enter a valid email",
    "minLength": "Minimum {min} characters required",
    "maxLength": "Maximum {max} characters allowed"
  }
}

// locales/id.json
{
  "common": {
    "save": "Simpan",
    "cancel": "Batal",
    "delete": "Hapus",
    "edit": "Ubah",
    "search": "Cari",
    "loading": "Memuat...",
    "noData": "Tidak ada data"
  },
  "auth": {
    "login": "Masuk",
    "logout": "Keluar",
    "email": "Email",
    "password": "Kata Sandi",
    "forgotPassword": "Lupa Kata Sandi?",
    "loginSuccess": "Berhasil masuk",
    "loginFailed": "Gagal masuk"
  },
  "inventory": {
    "title": "Inventaris",
    "addProduct": "Tambah Produk",
    "productName": "Nama Produk",
    "sku": "SKU",
    "price": "Harga",
    "stock": "Stok",
    "category": "Kategori"
  },
  "validation": {
    "required": "Field ini wajib diisi",
    "email": "Masukkan email yang valid",
    "minLength": "Minimal {min} karakter",
    "maxLength": "Maksimal {max} karakter"
  }
}

// locales/ja.json
{
  "common": {
    "save": "保存",
    "cancel": "キャンセル",
    "delete": "削除",
    "edit": "編集",
    "search": "検索",
    "loading": "読み込み中...",
    "noData": "データがありません"
  },
  "auth": {
    "login": "ログイン",
    "logout": "ログアウト",
    "email": "メール",
    "password": "パスワード",
    "forgotPassword": "パスワードをお忘れですか？",
    "loginSuccess": "ログインに成功しました",
    "loginFailed": "ログインに失敗しました"
  },
  "inventory": {
    "title": "在庫",
    "addProduct": "商品を追加",
    "productName": "商品名",
    "sku": "SKU",
    "price": "価格",
    "stock": "在庫",
    "category": "カテゴリー"
  }
}

Usage in Components

Basic Usage with $t

<template>
  <div>
    <h1>{{ $t('inventory.title') }}</h1>

    <UButton>{{ $t('common.save') }}</UButton>
    <UButton variant="outline">{{ $t('common.cancel') }}</UButton>

    <UInput :placeholder="$t('common.search')" />
  </div>
</template>

With useI18n Composable

<script setup lang="ts">
const { t, locale, locales, setLocale } = useI18n()

// Get current locale
console.log(locale.value) // 'id'

// Get available locales
console.log(locales.value) // [{ code: 'en', name: 'English' }, ...]

// Change locale
const switchLanguage = (code: string) => {
  setLocale(code)
}
</script>

<template>
  <div>
    <h1>{{ t('inventory.title') }}</h1>

    <!-- Language Switcher -->
    <USelect
      :model-value="locale"
      :options="locales.map(l => ({ label: l.name, value: l.code }))"
      @update:model-value="switchLanguage"
    />
  </div>
</template>

With Parameters

<template>
  <!-- locales/en.json: "welcome": "Welcome, {name}!" -->
  <p>{{ $t('welcome', { name: user.name }) }}</p>

  <!-- locales/en.json: "items": "{count} item | {count} items" -->
  <p>{{ $t('items', { count: itemCount }, itemCount) }}</p>

  <!-- locales/en.json: "minLength": "Minimum {min} characters required" -->
  <p>{{ $t('validation.minLength', { min: 8 }) }}</p>
</template>

Pluralization

// locales/en.json
{
  "cart": {
    "items": "No items | 1 item | {count} items"
  }
}

<template>
  <p>{{ $t('cart.items', itemCount) }}</p>
  <!-- 0 items → "No items" -->
  <!-- 1 item → "1 item" -->
  <!-- 5 items → "5 items" -->
</template>

Language Switcher Component

<!-- components/LanguageSwitcher.vue -->
<script setup lang="ts">
const { locale, locales, setLocale } = useI18n()

const currentLocale = computed(() =>
  locales.value.find(l => l.code === locale.value)
)

const items = computed(() =>
  locales.value.map(l => [{
    label: l.name,
    click: () => setLocale(l.code),
    active: l.code === locale.value,
  }])
)
</script>

<template>
  <UDropdown :items="items">
    <UButton variant="ghost" class="flex items-center gap-2">
      <UIcon name="i-heroicons-globe-alt" />
      <span>{{ currentLocale?.name }}</span>
      <UIcon name="i-heroicons-chevron-down" class="w-4 h-4" />
    </UButton>
  </UDropdown>
</template>

Formatting

Date Formatting

<script setup lang="ts">
const { d, locale } = useI18n()

const date = new Date()
</script>

<template>
  <p>{{ d(date, 'short') }}</p>
  <p>{{ d(date, 'long') }}</p>
</template>

Configure date formats in each locale:

// locales/id.json
{
  "dateTimeFormats": {
    "short": {
      "year": "numeric",
      "month": "short",
      "day": "numeric"
    },
    "long": {
      "year": "numeric",
      "month": "long",
      "day": "numeric",
      "weekday": "long"
    }
  }
}

Number Formatting

<script setup lang="ts">
const { n, locale } = useI18n()

const price = 1500000
</script>

<template>
  <p>{{ n(price, 'currency') }}</p>
  <!-- id: Rp 1.500.000 -->
  <!-- en: $1,500,000 -->
  <!-- ja: ¥1,500,000 -->
</template>

Configure number formats:

// locales/id.json
{
  "numberFormats": {
    "currency": {
      "style": "currency",
      "currency": "IDR",
      "currencyDisplay": "symbol"
    },
    "decimal": {
      "style": "decimal",
      "minimumFractionDigits": 2,
      "maximumFractionDigits": 2
    }
  }
}

Persisting Language Preference

// composables/useLanguagePreference.ts
export const useLanguagePreference = () => {
  const { locale, setLocale } = useI18n()

  // Load saved preference on mount
  onMounted(() => {
    const saved = localStorage.getItem('language')
    if (saved) {
      setLocale(saved)
    }
  })

  // Save preference when changed
  watch(locale, (newLocale) => {
    localStorage.setItem('language', newLocale)
  })

  return { locale, setLocale }
}

Integration with Backend

Sending Locale to API

// plugins/api.client.ts
export default defineNuxtPlugin(() => {
  const { locale } = useI18n()

  const $api = $fetch.create({
    onRequest({ options }) {
      // Send locale header to backend
      options.headers = {
        ...options.headers,
        'Accept-Language': locale.value,
      }
    },
  })

  return {
    provide: { api: $api },
  }
})

Translating Backend Errors

// composables/useApiError.ts
export const useApiError = () => {
  const { t } = useI18n()

  const translateError = (error: ApiError): string => {
    // Try to find translation for error code
    const translationKey = `errors.${error.code}`

    // Check if translation exists
    if (t(translationKey) !== translationKey) {
      return t(translationKey, error.params || {})
    }

    // Fallback to original message
    return error.message
  }

  return { translateError }
}

Organizing Translations

For large applications, organize translations by feature:

locales/
├── en/
│   ├── common.json
│   ├── auth.json
│   ├── inventory.json
│   ├── sales.json
│   └── index.ts       # Merge all
├── id/
│   ├── common.json
│   ├── auth.json
│   ├── inventory.json
│   ├── sales.json
│   └── index.ts
└── ja/
    └── ...

// locales/en/index.ts
import common from './common.json'
import auth from './auth.json'
import inventory from './inventory.json'
import sales from './sales.json'

export default {
  ...common,
  auth,
  inventory,
  sales,
}

Best Practices

Key Naming Convention

Use hierarchical keys:

{
  "module.section.action": "Translation"
}

Example:

inventory.form.save
auth.error.invalidCredentials
common.button.cancel

Lazy Loading

Enable lazy loading untuk mengurangi initial bundle size:

i18n: {
  lazy: true,
  langDir: 'locales'
}

Default Locale

Selalu set default locale:

i18n: {
  defaultLocale: 'id',
  fallbackLocale: 'en' // Fallback jika key tidak ditemukan
}

Missing Translations

Handle missing translations gracefully:

<template>
  <!-- Will show key if translation missing -->
  {{ $t('some.missing.key') }}

  <!-- With fallback -->
  {{ $t('some.missing.key', 'Default Text') }}
</template>

UI Framework

i18n Localization

i18n Localization

Configuration

Locale Files Structure

Example Locale Files

Usage in Components

Basic Usage with $t

With useI18n Composable

With Parameters

Pluralization

Language Switcher Component

Formatting

Date Formatting

Number Formatting

Persisting Language Preference

Integration with Backend

Sending Locale to API

Translating Backend Errors

Organizing Translations

Best Practices

Next Steps

Nuxt UI Components

Development Guide

UI Framework

​i18n Localization

​Configuration

​Locale Files Structure

​Example Locale Files

​Usage in Components

​Basic Usage with $t

​With useI18n Composable

​With Parameters

​Pluralization

​Language Switcher Component

​Formatting

​Date Formatting

​Number Formatting

​Persisting Language Preference

​Integration with Backend

​Sending Locale to API

​Translating Backend Errors

​Organizing Translations

​Best Practices

​Next Steps

Nuxt UI Components

Development Guide

i18n Localization

Configuration

Locale Files Structure

Example Locale Files

Usage in Components

Basic Usage with $t

With useI18n Composable

With Parameters

Pluralization

Language Switcher Component

Formatting

Date Formatting

Number Formatting

Persisting Language Preference

Integration with Backend

Sending Locale to API

Translating Backend Errors

Organizing Translations

Best Practices

Next Steps