intl-pluralrules

What is intl-pluralrules?

The intl-pluralrules npm package is a polyfill for the ECMAScript Internationalization API's PluralRules object. It provides a way to get the plural form of a number for a given locale, which is useful for internationalizing applications.

What are intl-pluralrules's main functionalities?

Basic Usage

This feature allows you to create an instance of Intl.PluralRules for a specific locale and use it to determine the plural form of a number.

const IntlPluralRules = require('intl-pluralrules');
const pr = new IntlPluralRules('en-US');
console.log(pr.select(1)); // 'one'
console.log(pr.select(2)); // 'other'

Using Different Locales

This feature demonstrates how to use the package with different locales. In this example, the locale is set to French (fr-FR).

const IntlPluralRules = require('intl-pluralrules');
const prFrench = new IntlPluralRules('fr-FR');
console.log(prFrench.select(1)); // 'one'
console.log(prFrench.select(2)); // 'other'

Handling Multiple Plural Categories

This feature shows how the package can handle multiple plural categories, which is particularly useful for languages like Arabic that have more than two plural forms.

const IntlPluralRules = require('intl-pluralrules');
const prArabic = new IntlPluralRules('ar-EG');
console.log(prArabic.select(0)); // 'zero'
console.log(prArabic.select(1)); // 'one'
console.log(prArabic.select(2)); // 'two'
console.log(prArabic.select(3)); // 'few'
console.log(prArabic.select(11)); // 'many'
console.log(prArabic.select(100)); // 'other'

Other packages similar to intl-pluralrules

make-plural

The make-plural package provides similar functionality by generating pluralization functions for different locales. It is more customizable and can be used to generate plural rules for a wide range of languages.

cldrjs

The cldrjs package is a JavaScript library for using Unicode CLDR (Common Locale Data Repository) data. It provides comprehensive localization support, including pluralization rules, and is more extensive in scope compared to intl-pluralrules.

globalize

The globalize package is a library for internationalization and localization in JavaScript. It uses CLDR data and provides a wide range of features including number formatting, date and time formatting, and pluralization. It is more feature-rich compared to intl-pluralrules.

README

intl-pluralrules

A spec-compliant implementation & polyfill for Intl.PluralRules, including the selectRange(start, end) method introduced in Intl.NumberFormat v3. Also useful if you need proper support for minimumFractionDigits, which are only supported in Chrome 77 & later.

For a polyfill without selectRange() and with IE 11 support, please use intl-pluralrules@1.

Installation

npm install intl-pluralrules

Polyfill

To use as a polyfill, just import it to ensure that Intl.PluralRules is available in your environment:

import 'intl-pluralrules'

If Intl.PluralRules already exists, includes a selectRange() method, and supports multiple locales, the polyfill will not be loaded.

Ponyfill

A complete implementation of PluralRules is available as intl-pluralrules/plural-rules, if you'd prefer using it without modifying your Intl object, or if you wish to use it rather than your environment's own:

import PluralRules from 'intl-pluralrules/plural-rules'

new PluralRules('en').select(1) // 'one'
new PluralRules('en', { minimumSignificantDigits: 3 }).select(1) // 'other'
new PluralRules('en').selectRange(0, 1) // 'other'
new PluralRules('fr').selectRange(0, 1) // 'one'

Factory

In order to support all available locales, their data needs to be included in the package. This means that when minified and gzipped, the above-documented usage adds about 7kB to your application's production size. If this is a concern, you can use intl-pluralrules/factory and make-plural to build a PluralRules class with locale support limited to only what you actually use.

Thanks to tree-shaking, this example that only supports English and French minifies & gzips to 1472 bytes. Do note that this size difference is only apparent with minified production builds.

import getPluralRules from 'intl-pluralrules/factory'
import { en, fr } from 'make-plural/plurals'
import { en as enCat, fr as frCat } from 'make-plural/pluralCategories'
import { en as enRange, fr as frRange } from 'make-plural/ranges'

const sel = { en, fr }
const getSelector = lc => sel[lc]

const cat = { en: enCat, fr: frCat }
const getCategories = (lc, ord) => cat[lc][ord ? 'ordinal' : 'cardinal']

const range = { en: enRange, fr: frRange }
const getRangeSelector = lc => range[lc]

const PluralRules = getPluralRules(
  Intl.NumberFormat, // Not available in IE 10
  getSelector,
  getCategories,
  getRangeSelector
)
export default PluralRules

All arguments of getPluralRules(NumberFormat, getSelector, getCategories, getRangeSelector) are required.

• NumberFormat should be Intl.NumberFormat, or an implementation which supports at least the "en" locale and all of the min/max digit count options.
• getSelector(lc) should return a function(n, ord) returning the plural category of n, using cardinal plural rules (by default), or ordinal rules if ord is true. n may be a number, or the formatted string representation of a number. This may be called with any user-provided string lc, and should return undefined for invalid or unsupported locales.
• getCategories(lc, ord) should return the set of available plural categories for the locale, either for cardinals (by default), or ordinals if ord is true. This function will be called only with values for which getSelector returns a function.
• getRangeSelector(lc) should return a function(start, end) returning the plural category of the range. start and end are the plural categories of the corresponding values.