y18n

What is y18n?

The y18n npm package is a library that provides internationalization (i18n) support for your Node.js applications. It allows you to define translations for your application's text strings and switch between different languages at runtime based on user preferences or other criteria.

What are y18n's main functionalities?

Locale String Translation

This feature allows you to translate strings into different locales. You define a set of translations for each language, and y18n will replace placeholders with the appropriate translations.

{"en": {"My cat is %s": "My cat is %s"}, "es": {"My cat is %s": "Mi gato es %s"}}

Pluralization

y18n supports pluralization, which means it can handle different translations based on the number of items. This is useful for languages that have different word forms depending on the count.

{"en": {"cat": {"one": "%d cat", "other": "%d cats"}}, "es": {"cat": {"one": "%d gato", "other": "%d gatos"}}}

Locale Switching

With y18n, you can switch the active locale at runtime, which allows your application to change languages on the fly based on user input or other conditions.

y18n.setLocale('es');

Other packages similar to y18n

i18next

i18next is a very popular internationalization framework for JavaScript. It offers a rich feature set including variable replacement, nesting, formatting, and more. It is more feature-rich and has a larger ecosystem than y18n, including plugins for frontend frameworks and backend integrations.

react-intl

react-intl is designed specifically for React applications and provides React components and an API to format dates, numbers, and strings, including pluralization and handling translations. It is more specialized for React than y18n, which is more general-purpose.

polyglot.js

Polyglot.js is a tiny I18n helper library that provides simple translation and pluralization. It is smaller and has a simpler API compared to y18n, making it a good choice for projects that require a lightweight solution.

README

y18n

The bare-bones internationalization library used by yargs.

Inspired by i18n.

Examples

simple string translation:

const __ = require('y18n')().__;

console.log(__('my awesome string %s', 'foo'));

output:

my awesome string foo

using tagged template literals

const __ = require('y18n')().__;

const str = 'foo';

console.log(__`my awesome string ${str}`);

output:

my awesome string foo

pluralization support:

const __n = require('y18n')().__n;

console.log(__n('one fish %s', '%d fishes %s', 2, 'foo'));

output:

2 fishes foo

Deno Example

As of v5 y18n supports Deno:

import y18n from "https://deno.land/x/y18n/deno.ts";

const __ = y18n({
  locale: 'pirate',
  directory: './test/locales'
}).__

console.info(__`Hi, ${'Ben'} ${'Coe'}!`)

You will need to run with --allow-read to load alternative locales.

JSON Language Files

The JSON language files should be stored in a ./locales folder. File names correspond to locales, e.g., en.json, pirate.json.

When strings are observed for the first time they will be added to the JSON file corresponding to the current locale.

Methods

require('y18n')(config)

Create an instance of y18n with the config provided, options include:

• directory: the locale directory, default ./locales.
• updateFiles: should newly observed strings be updated in file, default true.
• locale: what locale should be used.
• fallbackToLanguage: should fallback to a language-only file (e.g. en.json) be allowed if a file matching the locale does not exist (e.g. en_US.json), default true.

y18n.__(str, arg, arg, arg)

Print a localized string, %s will be replaced with args.

This function can also be used as a tag for a template literal. You can use it like this: __`hello ${'world'}`. This will be equivalent to __('hello %s', 'world').

y18n.__n(singularString, pluralString, count, arg, arg, arg)

Print a localized string with appropriate pluralization. If %d is provided in the string, the count will replace this placeholder.

y18n.setLocale(str)

Set the current locale being used.

y18n.getLocale()

What locale is currently being used?

y18n.updateLocale(obj)

Update the current locale with the key value pairs in obj.

Supported Node.js Versions

Libraries in this ecosystem make a best effort to track Node.js' release schedule. Here's a post on why we think this is important.

License

ISC