Awesome
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 beIntl.NumberFormat
, or an implementation which supports at least the"en"
locale and all of the min/max digit count options.getSelector(lc)
should return afunction(n, ord)
returning the plural category ofn
, using cardinal plural rules (by default), or ordinal rules iford
is true.n
may be a number, or the formatted string representation of a number. This may be called with any user-provided stringlc
, and should returnundefined
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 iford
is true. This function will be called only with values for whichgetSelector
returns a function.getRangeSelector(lc)
should return afunction(start, end)
returning the plural category of the range.start
andend
are the plural categories of the corresponding values.