nuxt-i18n-micro

Nuxt I18n Micro

Nuxt I18n Micro is a fast, simple, and lightweight internationalization (i18n) module for Nuxt. Despite its compact size, it's designed with large projects in mind, offering significant performance improvements over traditional i18n solutions like nuxt-i18n. The module was built from the ground up to be highly efficient, focusing on minimizing build times, reducing server load, and shrinking bundle sizes.

Why Nuxt I18n Micro?

The Nuxt I18n Micro module was created to address critical performance issues found in the original nuxt-i18n module, particularly in high-traffic environments and projects with large translation files. Key issues with nuxt-i18n include:

• High Memory Consumption: Consumes significant memory during both build and runtime, leading to performance bottlenecks.
• Slow Performance: Especially with large translation files, it causes noticeable slowdowns in build times and server response.
• Large Bundle Size: Generates a large bundle, negatively impacting application performance.
• Memory Leaks and Bugs: Known for memory leaks and unpredictable behavior under heavy load.

Performance Comparison

To showcase the efficiency of Nuxt I18n Micro, we conducted tests under identical conditions. Both modules were tested with a 10MB translation file on the same hardware.

Build Time and Resource Consumption

Nuxt I18n:

• Total size: 54.7 MB (3.31 MB gzip)
• Max CPU Usage: 391.4%
• Max Memory Usage: 8305 MB
• Elapsed Time: 0h 1m 31s

Nuxt I18n Micro:

• Total size: 1.93 MB (473 kB gzip) — 96% smaller
• Max CPU Usage: 220.1% — 44% lower
• Max Memory Usage: 655 MB — 92% less memory
• Elapsed Time: 0h 0m 5s — 94% faster

Server Performance (10k Requests)

Nuxt I18n:

• Requests per second: 49.05 [#/sec] (mean)
• Time per request: 611.599 ms (mean)
• Max Memory Usage: 703.73 MB

Nuxt I18n Micro:

• Requests per second: 61.18 [#/sec] (mean) — 25% more requests per second
• Time per request: 490.379 ms (mean) — 20% faster
• Max Memory Usage: 323.00 MB — 54% less memory usage

These results clearly demonstrate that Nuxt I18n Micro significantly outperforms the original module in every critical area.

Key Features

• 🌐 Compact Yet Powerful: Despite its small size, Nuxt I18n Micro is designed for large-scale projects, focusing on performance and efficiency.
• ⚡ Optimized Build and Runtime: Reduces build times, memory usage, and server load, making it ideal for high-traffic applications.
• 🛠 Minimalist Design: The module is structured around just 5 components (1 module and 4 plugins), making it easy to understand, extend, and maintain.
• 📏 Efficient Routing: Generates only 2 routes regardless of the number of locales, thanks to dynamic regex-based routing, unlike other i18n modules that generate separate routes for each locale.
• 🗂 Streamlined Translation Loading: Only JSON files are supported, with translations split between a global file for common texts (e.g., menus) and page-specific files, which are auto-generated in the dev mode if not present.

Quick Setup

Install the module in your Nuxt application with:

npm install nuxt-i18n-micro

Then, add it to your nuxt.config.ts:

export default defineNuxtConfig({
  modules: [
    'nuxt-i18n-micro',
  ],
  i18n: {
    locales: [
      { code: 'en', iso: 'en-US', dir: 'ltr' },
      { code: 'fr', iso: 'fr-FR', dir: 'ltr' },
      { code: 'ar', iso: 'ar-SA', dir: 'rtl' },
    ],
    defaultLocale: 'en',
    translationDir: 'locales',
    meta: true,
  },
})

That's it! You're now ready to use Nuxt I18n Micro in your Nuxt app.

Folder Structure

Translations are organized into global and page-specific files:

/locales
  /pages
    /index
      en.json
      fr.json
      ar.json
    /about
      en.json
      fr.json
      ar.json
  en.json
  fr.json
  ar.json

• Global File: Located at locales/{locale}.json (e.g., locales/en.json). Used for common texts shared across multiple pages, such as menus.
• Page-Specific Files: Located at locales/pages/{routeName}/{locale}.json (e.g., locales/pages/index/en.json). These are used for translations specific to individual pages.

Plugin Methods

$getLocale()

Returns the current locale code.

const locale = $getLocale()

$getLocales()

Returns an array of all available locales configured in the module.

const locales = $getLocales()

$t(key: string, params?: Record<string, any>, defaultValue?: string)

Fetches a translation for the given key. Optionally interpolates parameters into the translation.

const welcomeMessage = $t('welcome', { username: 'Alice', unreadCount: 5 })

$tc(key: string, count: number, defaultValue?: string)

Fetches a pluralized translation for the given key based on the count.

const appleCountMessage = $tc('apples', 10)

$switchLocale(locale: string)

Switches to the given locale and redirects the user to the appropriate localized route.

$switchLocale('fr')

$localeRoute(to: RouteLocationRaw, locale?: string): RouteLocationRaw

Generates a localized route object based on the target route.

const localizedRoute = $localeRoute({ name: 'index' })

$mergeTranslations(newTranslations: Translations)

Merges new translations into the existing translation cache for the current route and locale.

$mergeTranslations({
  welcome: 'Bienvenue, {username}!'
})

$defineI18nRoute(routeDefinition: { locales?: string[] | Record<string, Record<string, TranslationObject>> })

Defines route behavior based on the current locale. This method can be used to control access to specific routes based on available locales or to provide translations for specific locales.

• locales: This property determines which locales are available for the route. It can be either:
  • An array of strings, where each string represents an available locale (e.g., ['en', 'fr', 'de']).
  • An object where each key is a locale code, and the value is either an object containing translations or an empty object if you do not wish to provide translations for that locale.

Example 1: Controlling Access Based on Locales

import { useNuxtApp } from '#imports'

const { $defineI18nRoute } = useNuxtApp()

$defineI18nRoute({
  locales: ['en', 'fr', 'de'] // Only these locales are allowed for this route
})

Example 2: Providing Translations for Locales

import { useNuxtApp } from '#imports'

const { $defineI18nRoute } = useNuxtApp()

$defineI18nRoute({
  locales: {
    en: { greeting: 'Hello', farewell: 'Goodbye' },
    fr: { greeting: 'Bonjour', farewell: 'Au revoir' },
    de: { greeting: 'Hallo', farewell: { aaa: { bbb: "Auf Wiedersehen" } } },
    ru: {} // Russian locale is allowed but no translations are provided
  }
})

Explanation:

• Locales Array: If you only want to specify which locales are allowed for a route, pass an array of locale codes. The user will only be able to access this route if the current locale is in this list.
• Locales Object: If you want to provide specific translations for each locale, pass an object where each key is a locale code. The value should be an object with key-value pairs for translations. If you do not wish to provide translations for a locale but still want to allow access, pass an empty object ({}) for that locale.

useNuxtApp

import { useNuxtApp } from '#imports'

const { $getLocale, $switchLocale, $getLocales, $localeRoute, $t } = useNuxtApp()

Composable

import { useI18n } from '#imports'

const { $getLocale, $switchLocale, $getLocales, $localeRoute, $t } = useI18n()
// or
const i18n = useI18n()

Example

<template>
  <div>
    <p>{{ $t('key2.key2.key2.key2.key2') }}</p>
    <p>Current Locale: {{ $getLocale() }}</p>

    <div>
      {{ $t('welcome', { username: 'Alice', unreadCount: 5 }) }}
    </div>
    <div>
      {{ $tc('apples', 10) }}
    </div>

    <div>
      <button
        v-for="locale in $getLocales()"
        :key="locale"
        :disabled="locale === $getLocale()"
        @click="$switchLocale(locale.code)"
      >
        Switch to {{ locale.code }}
      </button>
    </div>

    <div>
      <NuxtLink :to="$localeRoute({ name: 'index' })">
        Go to Index
      </NuxtLink>
    </div>
  </div>
</template>

<script setup>
  import { useI18n } from '#imports'

  const { $getLocale, $switchLocale, $getLocales, $localeRoute, $t, $tc } = useI18n()
</script>

Module Options

The module accepts the following options in the Nuxt configuration:

locales: An array of locale objects. Each locale should have the following properties:

• code: (string, required) A unique identifier for the locale, such as 'en' for English or 'fr' for French.
• iso: (string, optional) The ISO code for the locale, which is typically used for setting the lang attribute in HTML or for other internationalization purposes (e.g., 'en-US', 'fr-FR').
• dir: (string, optional) The text direction for the locale. It can be either 'rtl' for right-to-left languages (like Arabic or Hebrew) or 'ltr' for left-to-right languages (like English or French). This is useful for ensuring that text is displayed correctly depending on the language's writing system.
• disabled: (boolean, optional) A flag indicating whether this locale should be disabled or excluded from certain layers or operations. When disabled is set to true, this locale will be ignored in situations where only active or enabled locales are considered. This can be particularly useful when working with different layers of content or features in a multi-locale application, allowing developers to temporarily or permanently exclude specific locales from being processed, displayed, or made available to users without removing them entirely from the configuration.

locales: [
  { code: 'en', iso: 'en' },
  { code: 'fr' },
  { code: 'ar', iso: 'ar-SA', dir: 'rtl' }
]

meta: A boolean indicating whether to automatically generate SEO-related meta tags (like alternate links).

defaultLocale: The default locale code (e.g., 'en').

translationDir: The directory where translation files are stored (e.g., 'locales').

autoDetectLanguage: If true, automatically detects the user's preferred language and redirects accordingly.

plural: A custom function for handling pluralization.

includeDefaultLocaleRoute: A boolean. If enabled, all routes without a locale prefix will redirect to the default locale route.

cache: (In development) A boolean option designed to optimize performance when working with large JSON translation files. When enabled, it caches translations specific to the current page, reducing search times and minimizing client-side load. This cached data is then sent to the client, resulting in faster page loads and improved user experience.

Locale Loading in Nuxt I18n Micro

The Nuxt I18n Micro module provides an efficient way to manage internationalization (i18n) in your Nuxt application, with a focus on performance and simplicity. One of the key features of this module is how it handles the loading of locale-specific translations. Below is an explanation of how this process works.

How Locale Loading Works

In Nuxt I18n Micro, translations are loaded dynamically based on the user's selected locale. The module uses a specific route pattern (/_locales/:page/:locale/data.json) to fetch the translation files for each page and locale. This approach is designed to minimize the initial load time and only load the necessary translations for the current page and locale.

Route Structure

The translations are organized into JSON files located in the locales directory. These files are split into:

• Global Files: Located at locales/{locale}.json (e.g., locales/en.json). These files contain translations shared across the entire application, such as menu items or common UI elements.
• Page-Specific Files: Located at locales/pages/{routeName}/{locale}.json (e.g., locales/pages/index/en.json). These files contain translations specific to individual pages.

Dynamic Locale Routes

To accommodate the dynamic nature of translation loading, Nuxt I18n Micro extends the default routing configuration by adding locale-specific routes. This means that for each page, a localized version of the route is generated. For example, if your application has an index page and supports English (en) and French (fr), the following routes would be generated:

• /en/index
• /fr/index

This structure allows the module to load the appropriate translations based on the user's selected locale.

Loading Translations via _locales Route

Given the way Vite and Nuxt handle modules, the Nuxt I18n Micro module uses a special route (/_locales/:page/:locale/data.json) to fetch translations. This is necessary because, during the build process, Vite may not bundle all translation files directly into the application. Instead, the module dynamically loads these files from the server as needed.

When a user navigates to a page, the module will:

1. Check if the necessary translation file for the current page and locale is already loaded in the cache.
2. If not, it will send a request to the _locales route to fetch the required translation file.
3. Once the translation file is loaded, it is cached for future use, ensuring that the translations are readily available when the user navigates to another part of the application.

Caching and Pre-rendering

To further optimize performance, Nuxt I18n Micro supports caching and pre-rendering of translation files:

• Caching: Once a translation file is loaded, it is stored in the cache, reducing the need for subsequent requests.
• Pre-rendering: During the build process, the module can pre-render translation files for all configured locales and routes, which are then served directly from the server without the need for runtime requests.

Certainly! Here's an updated section for your README that includes the description of the <i18n-t> component, along with explanations for each prop and examples of usage.

---

<i18n-t> Component

The <i18n-t> component in Nuxt I18n Micro is a flexible and powerful tool designed to handle translations within your Nuxt application. It supports various features such as interpolation, pluralization, and dynamic HTML rendering.

Component Props

• keypath (string, required): The translation key used to look up the corresponding translation string from the locale files.

• plural (number | null, optional): The count used for pluralization. If provided, the component will use the $tc method for translating based on the pluralization rules defined for the locale.

• tag (string, optional, default: 'span'): The HTML tag used to wrap the translated content. You can specify any valid HTML tag, such as div, p, h1, etc.

• scope (string, optional, default: 'global'): Specifies the scope of the translation. This prop is useful if you have different translation scopes in your application, although the default is set to 'global'.

• params (Record<string, string | number | boolean>, optional, default: () => ({})): An object containing key-value pairs to be interpolated into the translation string. This is useful for dynamic translations where certain values need to be inserted into the text.

• defaultValue (string, optional, default: ''): A fallback translation that will be displayed if the keypath does not match any key in the translation files.

• html (boolean, optional, default: false): A flag indicating whether the translation contains HTML. When set to true, the translated string will be rendered as raw HTML.

• locale (string, optional): The locale to use for this translation. If not provided, the component will use the current locale set by the application.

• wrap (boolean, optional, default: true): Determines if the translated content should be wrapped in the specified tag. If set to false, the component will not wrap the translation in an HTML element.

• customPluralRule ((value: string, count: number, locale: string) => string, optional): A custom function for handling pluralization. This allows you to override the default pluralization behavior with your custom logic.

• hideIfEmpty (boolean, optional, default: false): If true, the component will not render anything if the translation string is empty. This is useful for conditional rendering based on the presence of a translation.

Examples of Usage

Basic Usage

<i18n-t keypath="welcomeMessage"></i18n-t>

This will render the translation associated with the key welcomeMessage using the current locale.

Pluralization

<i18n-t keypath="apples" :plural="10" tag="div"></i18n-t>

This will handle the pluralization for the translation key apples and render it inside a div element.

Interpolation with Parameters

<i18n-t keypath="greeting" :params="{ name: 'John' }"></i18n-t>

Assuming the translation string is "Hello, {name}!", this will render "Hello, John!".

Rendering with HTML Content

<i18n-t keypath="richText" :html="true"></i18n-t>

If richText contains HTML content like "<strong>Welcome</strong> to our site!", setting html to true will render the HTML directly.

Using a Custom Locale

<i18n-t keypath="welcomeMessage" locale="fr"></i18n-t>

This will render the translation in French, overriding the application's current locale.

Conditional Rendering

<i18n-t keypath="optionalMessage" :hideIfEmpty="true"></i18n-t>

This will render nothing if the translation for optionalMessage is empty.

Custom Pluralization Rule

<i18n-t
  keypath="items"
  :plural="itemCount"
  :customPluralRule="(value, count, locale) => {
    return count === 1 ? 'One item' : value.replace('{count}', `${count}`)
  }"></i18n-t>

This uses a custom function to handle the pluralization, bypassing the default logic.

Advanced Example

<i18n-t
  keypath="notifications"
  :plural="unreadCount"
  tag="p"
  :params="{ username: 'Alice' }"
  defaultValue="You have no notifications"
  :html="false"
  locale="en"
  :wrap="true"
  :hideIfEmpty="false">
</i18n-t>

Slot Usage Example

Here's how you can use the slot and access the translation within it:

<i18n-t keypath="welcomeMessage">
  <template #default="{ translation }">
    <strong>{{ translation }}</strong>
  </template>
</i18n-t>

Explanation:

• Slot Prop translation:
  • The component now provides translation as a slot prop, which can be accessed in the parent component’s slot content.
  • In this example, the translation is wrapped in a <strong> tag, allowing you to apply custom styling or further modify how the translation is displayed.

---

The <i18n-t> component provides a powerful and flexible way to handle translations in your Nuxt application, accommodating a wide range of use cases from simple text translations to complex pluralization and HTML rendering scenarios.

Layers

In Nuxt I18n Micro, you can use the concept of layers to manage localization settings in your application. This approach allows you to configure internationalization flexibly depending on the context, and it also enables you to create and extend locale configurations across different parts of your application.

Primary Configuration Layer

The primary configuration layer (i18n) sets the default localization settings used throughout the application. In this layer, you define the main locales, the order in which they are used, SEO settings, behavior for detecting the user's language, and other relevant parameters.

Example of a basic configuration in the primary layer:

export default defineNuxtConfig({
  i18n: {
    locales: [
      { code: 'en', iso: 'en_EN' },
      { code: 'de', iso: 'de_DE' },
    ],
    meta: true, // Enable automatic SEO meta tags generation
    defaultLocale: 'en', // Default language
    translationDir: 'locales', // Directory for translation files
    autoDetectLanguage: true, // Automatically detect the user's language
  },
})

Extending and Modifying Settings in Child Layers

Child layers allow you to extend or modify the configuration set in the primary layer. This is particularly useful if you need to adapt localization settings for specific contexts or sections of your application while retaining the overall base configuration.

Example of using a child layer:

export default defineNuxtConfig({
  extends: '../basic', // Inherit the base configuration layer
  i18n: {
    locales: [
      { code: 'ru', iso: 'ru_RU' }, // Add a new locale for Russian
      { code: 'de', disabled: true }, // Disable the locale for German
    ],
  },
})

In this example:

• We extend the base configuration layer using extends: '../basic'.
• In the child layer, we add a new locale ru for Russian.
• We disable the de locale by setting disabled: true.

Conclusion

Nuxt I18n Micro offers a highly efficient, minimalist approach to internationalization in Nuxt applications. By focusing on performance and simplicity, it provides a powerful alternative to heavier, more complex i18n solutions. Whether you're building a small website or a large-scale application, Nuxt I18n Micro helps you manage multilingual content with ease.

For more details and updates, visit the Nuxt I18n Micro GitHub repository.

Changelog

v1.3.1

compare changes

🩹 Fixes

• Docs (7a1a0b0)

❤️ Contributors

• Pavel Kuzmin (@s00d)