a-i18n

Inspired by http://i18njs.com/

Install

npm install --save a-i18n

const i18n = require('a-i18n')

Usage

Simple

const en = i18n({ key: 'my message' })
const str = en('key')
console.log(str) // my message

Interpolation

You can interpolate numbers and strings using %n and %s.

const en = i18n({ 
  hello: 'Hello %s', 
  unread_messages: 'You have %n unread messages' 
})

en('hello', 'World') // Hello World
en('unread_messages', 4) // You have 4 unread messages

Interpolation will match by the first argument against the first token of the matching type.

const en = i18n({
  test: '%s %n %s %s %n'
})
en('test', 1, 2, 'a', 'b') // a 1 b %s 2

Note that the third "%s" was left because no argument matched it.

TODO Add option for user to specify how it should be handled (e.g. throw exception, replace with blank string, replace with default string specified by user)

Pluralization

As you noticed in the above example for unread messages, that message wouldn't look very nice if I only had 1 unread message.

const en = i18n({ 
  unread_messages: [
    [0, 0, 'You have no unread messages'], 
    [1, 1, 'You have %n unread message'], 
    [2, null, 'You have %n unread messages']] 
})
en('unread_messages', 1) // You have 1 unread message
en('unread_messages', 2) // You have 2 unread messages

Note that pluralization always assumes that the first argument controls pluralization.

const en = i18n({ 
  any: [
    [0, 0, '%s have no messages.'], 
    [1, null, '%s have messages.']
  ] 
})
en('any', 1, 'You') // This works
en('any', 'You', 1) // This would look at 'You' and since it is not a number default pluralization to 0

Names parameters

const en = i18n({ 
  welcome: 'Welcome %{name}! Your last visit was on %{lastVisit}.' 
})
en('welcome', { name: 'Andreas', lastVisit: '2017-01-01' }) // Welcome Andreas! Your last visit was on 2017-01-01.

Reference other messages

const en = i18n({ 
  hello: 'Hello %s! ${any_messages}', 
  any_messages: [
    [0, 0, 'You have no messages.'], 
    [1, 1, 'You have %n message.'], 
    [2, null, 'You have %n messages.']
  ]
})
en('hello', 1, 'Andreas') // Hello Andreas! You have 1 message.

Multiple languages

const en = i18n({ hello: 'Hello!' })
const sv = i18n({ hello: 'Hej!' })

Planned improvements

User can add multiple languages and receive correct language string based on browser language.

// Not final api, only example:

i18n.addLocale('en', { hello: 'Hello!' })
i18n.addLocale('sv', { hello: 'Hej! })

const fn = i18n.formatterForCurrentLocale()
fn('hello') // Hello! or Hej! depending on locale

const en = i18n.formatterForLocale('en')
en('hello') // Hello!

Add support for type agnostic interpolation

const en = i18n({ test: 'Hello {}! You are guest {} today.' })
en('test', 1, 2) // Hello 1! You are guest 2 today.