I18next with ability to download missing keys

Existing i18next offers backend plugins like i18next-xhr-backend, but those plugins are requesting keys by namespaces and not at the granularity of an individual key. The goal of this module is to be able to fetch missing keys individually, taking in consideration performances by debouncing the requests in a individual request.

Installation

# using npm
$ npm install i18next-keys-ondemand

# using yarn
$ yarn add i18next-keys-ondemand

Who to use it?

• Use the module when initializing i18next:

import * as i18n from 'i18next';
import { I18nextKeysOnDemand, TranslationMap } from 'i18next-keys-ondemand';



function translationService(keys: string[]) {
    // simulate AJAX call
    return new Promise<TranslationMap>((resolve) => {
        const result: TranslationMap = {};
        keys.map(k => { result[k] = 'translation of ' + k; });

        setTimeout(() => {
            resolve(result);
        },         50);
    });
}

i18n
  .use(new I18nextKeysOnDemand({ translationGetter: translationService })) // init i18next here
  .init({
    fallbackLng: 'en',
    ns: ['thenamespace'],
    defaultNS: 'thenamespace'
  });

• The options:

Field	Mandatory?	Default value	Comment
translationGetter	yes		Translation service to use
missingKeyValue	no	''	Value to return for missing keys
debounceDelay	no	100	Delay in ms used to debounce the translation requests