An Astro i18n library in GNU gettext style. Inspired by ttag

Project Status

astro-gettext is still experimental, but covers most of use-cases for simple static websites build with Astro.

Why

• Astro is awesome. It brings simpler syntax for the static website era.
• I'm a big fan of i18n using GNU gettext pattern.
• There's no such library to combine them. Lingui still don't support Astro (on Sep, 2023)

Getting Started

Install

npm install --save astro-gettext

Or if you use Yarn:

yarn add astro-gettext

Implementation

1. Setup translation

By creating a translation instance, you can declare your supported languages:

// src/locale.ts
import { Trans } from 'astro-gettext'

export const trans = new Trans<'en' | 'ja'>()

2. Wrap strings with t tag

---
// src/pages/index.astro
import { trans } from '../locale'

// You need to implement a logic to retrieve the current language.
// `Astro.url` is a recommended way, but it depends on your environment.
const t = trans.get(Astro.url.includes('ja') ? 'ja' : 'en')
---
<div>
  <h1>{t`Hello World!`}</h1>
</div>

3. Setup localization

npm run astro-gettext extract --po ja.po

This will create a new ja.po file with all appropriate translation templates for the Japanese language:

# ja.po
#: src/pages/index.astro:8
msgid "Hello World!"
msgstr ""

Let's add your translation by filling msgstr:

# ja.po
#: src/pages/index.astro:8
msgid "Hello World!"
msgstr "こんにちは！"

4. Load translations

Convert the .po into JSON file so that Astro can load them in runtime:

npm run astro-gettext po2json --po locales/ja.po --output src/ja.json --pretty

It will produce a json file like this:

{
  "charset": "utf-8",
  "translations": {
    "": {
      "Hello World!": {
        "msgid": "Hello World!",
        "msgstr": ["こんにちは！"]
      }
    }
  }
}

Finally, update the translation instance:

// src/locale.ts
import { Trans } from 'astro-gettext'
import ja from './ja.json' // <--- This

export const trans = new Trans<'en' | 'ja'>()
trans.addLocale('ja', ja) // <--- This

Well Done! Then you will see your Astro app is translated, in a manner of gettext.

TODO

• Support i18n in the gray-matter TS code area using ts-morph
• Variable support
• Context support
• ngettext support
• Covers .ts files using TypeScript compiler API - meaning this library truly become ttag replacement.
• Astro frontend integrations?