js-lingui

I would like to present an alternative i18n libraries which I develop.

• works both with Vanilla JS (lingui-i18n) and React (lingui-react)
• lingui-react is the only library which fully supports inline components and rich formatting (see below)
• build on top of ICU MessageFormat
• includes also CLI (lingui-cli) for building message catalogs
• it uses Flow types and a lot of validation during compile time to catch obvious errors in MessageFormat

Syntax

ICU MessageFormat is very flexible as it supports variables, plurals, ordinals, choices, number/date formatting and is also extensible. However, complex messages are a bit difficult to write.

lingui-i18n provides convenient syntax using ES6 tagged template literals, while lingui-react provides similar syntax using React Components

Vanilla JS

import { i18n } from 'lingui-i18n'i18n.t`Hello World`i18n.t`Hello, my name is ${name}`i18n.plural({ value: count, one: "# book", other: "# books" })

More examples in lingui-i18n docs

React

import React from 'react'import { Trans, Plural } from 'lingui-react'class App extends React.Component {  render() {    const name = "Fred"    const count = 42    return (      <div>      // Static text      <Trans>January</Trans>      // Variables      <Trans>Hello, my name is {name}</Trans>      // Components      <Trans>See the <a href="/more">description</a> below.</Trans>      // Plurals      <Plural         value={count}         zero={<strong>No books</strong>}        one="# book"         other="# books"       />      </div>    )  }}

docs are part of js-lingui main docs.

Inline components and rich formatting

I started writing this lib because I wanted a) easier syntax and b) full support for inline components.

Both react-intl and react-i18next have very limited support for rich text and inline components. You can either use basic html tags inside components (This is <strong>bold</strong> text.) or inject components as variables (This is {el} text. where el = <strong>bold</strong>).

The problem with the 1st approach is that you can't use custom React components. The problem with the 2nd approach is that translator works with 2 messages instead of one (This is {el} text. and bold). This is actually pretty bad because you need to translate the whole sentence to keep context.

With lingui-react you can use any React components inside translations and the message is extracted in one piece:

<Trans>See the <Link to="/more">description</Link> below.</Trans>// for translator: See the <0>description</0> below.

Another advantage of this solution is that component name and props are hidden in extracted message. I remember how we spent a lot of time updating translations only after we changed class on the inner element.

Just compare it with interpolation in react-i18next or react-intl.

Requirements

Both lingui-i18n and lingui-react require presets to make everything work. This is a problem if you want to use it with Create React App as you need to either eject or fork react-scripts.

The general choice is react-intl, which is widely more popular than react-i18next. It currently has 4.5k vs react-i18next's 300 stars on github.It is the go-to solution for localization in React.

Here's a tutorial to get started:https://medium.freecodecamp.com/internationalization-in-react-7264738274a0

Try https://github.com/alibaba/react-intl-universal which is developed by Alibaba Group.yahoo/react-intl can only be applied in view layer such as React.Component. For Vanilla JS file, there’s no way to internationalize it. For example, the following snippet is general form validator used by many React.Component in our apps.

export default const rules = {  noSpace(value) {    if (value.includes(' ')) {      return 'Space is not allowed.';    }  }};

alibaba/react-intl-universal is simple but powerful. It doesn’t change behavior of components. And can used in JSX and normal JS file.