README
fluent-langneg
fluent-langneg
is an API for negotiating languages. It's part of
Project Fluent, a localization framework designed to unleash
the expressive power of the natural language.
It's main function is to provide functionality around the Intl.Locale API with a focus on language negotiation, matching and selection.
Installation
fluent-langneg
can be used both on the client-side and the server-side.
You can install it from the npm registry or use it as a standalone script.
npm install fluent-langneg
How to use
import { negotiateLanguages } from 'fluent-langneg';
const supportedLocales = negotiateLanguages(
navigator.languages, // requested locales
['de', 'en-US', 'pl'], // available locales
{ defaultLocale: 'en-US' }
);
The API reference is available at https://projectfluent.org/fluent.js/fluent-langneg.
Strategies
The API supports three negotiation strategies:
filtering (default)
In this strategy the algorithm will look for the best matching available locale for each requested locale.
Example:
requested: ['de-DE', 'fr-FR'] available: ['it', 'de', 'en-US', 'fr-CA', 'de-DE', 'fr', 'de-AU']
supported: ['de-DE', 'fr']
matching
In this strategy the algorithm will try to match as many available locales as possible for each of the requested locale.
Example:
requested: ['de-DE', 'fr-FR'] available: ['it', 'de', 'en-US', 'fr-CA', 'de-DE', 'fr', 'de-AU']
supported: ['de-DE', 'de', 'fr', 'fr-CA']
lookup
In this strategy the algorithm will try to find the single best locale for the requested locale list among the available locales.
Example:
requested: ['de-DE', 'fr-FR'] available: ['it', 'de', 'en-US', 'fr-CA', 'de-DE', 'fr', 'de-AU']
supported: ['de-DE']
API use:
let supported = negotiateLanguages(requested, available, {
strategy: 'matching',
});
Likely subtags
Fluent Language Negotiation module carries its own minimal list of likely subtags data, which is useful in finding most likely available locales in case the requested locale is too generic.
An example of that scenario is when the user requests en
locale, and
the application supportes en-GB
and en-US
.
Learn more
Find out more about Project Fluent at projectfluent.org, including documentation of the Fluent file format (FTL), links to other packages and implementations, and information about how to get involved.