Intl.RelativeTimeFormat

A spec-compliant polyfill for Intl.RelativeTimeFormat fully tested by the official ECMAScript Conformance test suite

Installation

npm

npm i @formatjs/intl-relativetimeformat

yarn

yarn add @formatjs/intl-relativetimeformat

Requirements

This package requires the following capabilities:

• Intl.getCanonicalLocales or polyfill
• Intl.Locale or polyfill.
• Intl.PluralRules or polyfill.
• If you need formatToParts and have to support IE11- or Node 10-, you'd need to polyfill using @formatjs/intl-numberformat.

Usage

Via polyfill-fastly.io

You can use polyfill-fastly.io URL Builder to create a polyfill script tag for Intl.RelativeTimeFormat. By default the created URL does not come with any locale data. In order to add locale data, append Intl.RelativeTimeFormat.~locale.<locale> to your list of features. For example:

<!-- Polyfill Intl.RelativeTimeFormat, its dependencies & `en` locale data -->
<script src="https://polyfill-fastly.io/v3/polyfill.min.js?features=Intl.RelativeTimeFormat,Intl.RelativeTimeFormat.~locale.en"></script>

Simple

import '@formatjs/intl-relativetimeformat/polyfill'
import '@formatjs/intl-relativetimeformat/locale-data/en' // locale-data for en

Dynamic import + capability detection

import {shouldPolyfill} from '@formatjs/intl-relativetimeformat/should-polyfill'
async function polyfill(locale: string) {
  const unsupportedLocale = shouldPolyfill(locale)
  // This locale is supported
  if (!unsupportedLocale) {
    return
  }
  // Load the polyfill 1st BEFORE loading data
  await import('@formatjs/intl-relativetimeformat/polyfill-force')
  await import(
    `@formatjs/intl-relativetimeformat/locale-data/${unsupportedLocale}`
  )
}

Tests

This library is fully test262-compliant.